eaogorg.files.wordpress.com€¦ · Web viewGEOCHEMISTRY ARTICLES – May 2019. Analytical Chemistry. Fallaise, D., Konzuk, J., Cheyne, C., Mack, E.E., Longstaffe, J.G., 2019. Nontargeted

GEOCHEMISTRY ARTICLES – May 2019

Analytical Chemistry

Fallaise, D., Konzuk, J., Cheyne, C., Mack, E.E., Longstaffe, J.G., 2019. Nontargeted analysis of a non-aqueous-phase liquid from a chemical manufacturing site using nuclear magnetic resonance spectroscopy. Environmental Toxicology and Chemistry 38, 947-955.

Le Gresley, A., Broadberry, G., Robertson, C., Peron, J.-M.R., Robinson, J., O’Leary, S., 2019. Application of pure shift and diffusion NMR for the characterisation of crude and processed pyrolysis oil. Journal of Analytical and Applied Pyrolysis 140, 281-289.

Mannikko, D., Stoll, S., 2019. Vanadyl porphyrin speciation based on submegahertz ligand proton hyperfine couplings. Energy & Fuels 33, 4237-4243.

Mateos, R., Vera-López, S., Saz, M., Díez-Pascual, A.M., San Andrés, M.P., 2019. Graphene/sepiolite mixtures as dispersive solid-phase extraction sorbents for the analysis of polycyclic aromatic hydrocarbons in wastewater using surfactant aqueous solutions for desorption. Journal of Chromatography A 1596, 30-40.

Nouara, A., Panagiotopoulos, C., Sempéré, R., 2019. Simultaneous determination of neutral sugars, alditols and anhydrosugars using anion-exchange chromatography with pulsed amperometric detection: Application for marine and atmospheric samples. Marine Chemistry 213, 24-32.

Vieira, A.P., Portela, N.A., Neto, Á.C., Lacerda, V., Romão, W., Castro, E.V.R., Filgueiras, P.R., 2019. Determination of physicochemical properties of petroleum using 1H NMR spectroscopy combined with multivariate calibration. Fuel 253, 320-326.

Vongsvivut, J., Pérez-Guaita, D., Wood, B.R., Heraud, P., Khambatta, K., Hartnell, D., Hackett, M.J., Tobin, M.J., 2019. Synchrotron macro ATR-FTIR microspectroscopy for high-resolution chemical mapping of single cells. Analyst 144, 3226-3238.

Yang, Y., Mai, W., Gao, J., Hu, Z., Xu, J., Zou, S., 2019. An in-needle solid-phase microextraction device packed with etched steel wires for polycyclic aromatic hydrocarbons enrichment in water samples. Journal of Separation Science 42, 1750-1756.

Zhang, S., Zhu, J., Zhan, H., Meng, Z., Chen, R., Liang, H., Zhao, K., Yue, W., 2019. Laser-induced voltage application for identification of crude oils. Energy & Fuels 33, 3855-3858.

GAS CHROMATOGRAPHY/GC×GC/GC-MS

Cordero, C., Guglielmetti, A., Bicchi, C., Liberto, E., Baroux, L., Merle, P., Tao, Q., Reichenbach, S.E., 2019. Comprehensive two-dimensional gas chromatography coupled with time of flight mass spectrometry featuring tandem ionization: Challenges and opportunities for accurate fingerprinting studies. Journal of Chromatography A 1597, 132-141.

Darko, E., Thurbide, K.B., 2019. Dynamic control of gas chromatographic selectivity during the analysis of organic bases. Analytical Chemistry 91, 6682-6688.

Larson, E.A., Lee, J., Paulson, A., Lee, Y.J., 2019. Structural analysis of polyurethane monomers by pyrolysis GC TOFMS via dopant-assisted atmospheric pressure chemical ionization. Journal of The American Society for Mass Spectrometry 30, 1046-1058.

Liu, H., Raffin, G., Trutt, G., Dugas, V., Demesmay, C., Randon, J., 2019. Hyphenation of short monolithic silica capillary column with vacuum ultraviolet spectroscopy detector for light hydrocarbons separation. Journal of Chromatography A 1595, 174-179.

Nelson, R.K., Gosselin, K.M., Hollander, D.J., Murawski, S.A., Gracia, A., Reddy, C.M., Radović, J.R., 2019. Exploring the complexity of two iconic crude oil spills in the Gulf of Mexico (Ixtoc I and Deepwater Horizon) using comprehensive two-dimensional gas chromatography (GC × GC). Energy & Fuels 33, 3925-3933.

Reichenbach, S.E., Zini, C.A., Nicolli, K.P., Welke, J.E., Cordero, C., Tao, Q., 2019. Benchmarking machine learning methods for comprehensive chemical fingerprinting and pattern recognition. Journal of Chromatography A 1595, 158-167.

Schwanz, T.G., Bokowski, L.V.V., Marcelo, M.C.A., Jandrey, A.C., Dias, J.C., Maximiano, D.H., Canova, L.S., Pontes, O.F.S., Sabin, G.P., Kaiser, S., 2019. Analysis of chemosensory markers in cigarette smoke from different tobacco varieties by GC×GC-TOFMS and chemometrics. Talanta 202, 74-89.

Wang, L., Longo, W.M., Dillon, J.T., Zhao, J., Zheng, Y., Moros, M., Huang, Y., 2019. An efficient approach to eliminate steryl ethers and miscellaneous esters/ketones for gas chromatographic analysis of alkenones and alkenoates. Journal of Chromatography A 1596, 175-182.

IMAGING: AFM

Liu, X., Nie, B., Wang, W., Wang, Z., Zhang, L., 2019. The use of AFM in quantitative analysis of pore characteristics in coal and coal-bearing shale. Marine and Petroleum Geology 105, 331-337.

Sauerer, B., Al Abdulghani, A.J., Abdallah, M.S., Abdallah, W., 2019. Interfacial activity of characterized Middle Eastern asphaltenes. Energy & Fuels 33, 3723-3732.

Zhang, R., Neu, T.R., Li, Q., Blanchard, V., Zhang, Y., Schippers, A., Sand, W., 2019. Insight into interactions of thermoacidophilic archaea with elemental sulfur: Biofilm dynamics and EPS analysis. Frontiers in Microbiology 10, 896. doi: 810.3389/fmicb.2019.00896.

Zhang, Y., 2019. Nonalternant aromaticity and partial double bond in petroleum molecules revealed: Theoretical understanding of polycyclic aromatic hydrocarbons obtained by noncontact atomic force microscopy. Energy & Fuels 33, 3816-3820.

Wu, S., Zou, C., Ma, D., Zhai, X., Yu, H., Yu, Z., 2019. Reservoir property changes during CO2–brine flow-through experiments in tight sandstone: Implications for CO2 enhanced

oil recovery in the Triassic Chang 7 Member tight sandstone, Ordos Basin, China. Journal of Asian Earth Sciences 179, 200-210.

IMAGING: SEM, TEM, HIM

Al-Yasiri, M., Awad, A., Pervaiz, S., Wen, D., 2019. Influence of silica nanoparticles on the functionality of water-based drilling fluids. Journal of Petroleum Science and Engineering 179, 504-512.

Andreetto, F., Dela Pierre, F., Gibert, L., Natalicchio, M., Ferrando, S., 2019. Potential fossilized sulfide-oxidizing bacteria in the Upper Miocene sulfur-bearing limestones from the Lorca Basin (SE Spain): Paleoenvironmental implications. Frontiers in Microbiology 10, 1031. doi: 1010.3389/fmicb.2019.01031.

Betancur, S., Carrasco-Marín, F., Pérez-Cadenas, A.F., Franco, C.A., Jiménez, J., Manrique, E.J., Quintero, H., Cortés, F.B., 2019. Effect of magnetic iron core–carbon shell nanoparticles in chemical enhanced oil recovery for ultralow interfacial tension region. Energy & Fuels 33, 4158-4168.

Chavrit, D., Moreira, M.A., Fike, D.A., Moynier, F., 2019. Unusual neon isotopic composition in Neoproterozoic sedimentary rocks: Fluorine bearing mineral contribution or trace of an impact event? Chemical Geology 520, 52-59.

Chen, M., He, S., Yi, J., Zhang, B., Shu, Z., He, C., Yang, R., Dong, T., 2019. Development characteristics of organic pore in shale gas reservoir of Wufeng Formation-Member 1 of Longmaxi Formation in Pingqiao block, Fuling shale gas field Acta Petrolei Sinica 40, 423-433.

Chen, Z., Song, Y., Li, Z., Liu, S., Li, Y., Liu, G., Yang, W., Wang, Q., Yang, Y., Gao, F., 2019. The occurrence characteristics and removal mechanism of residual water in marine shales: A case study of Wufeng-Longmaxi shale in Changning-Weiyuan area, Sichuan basin. Fuel 253, 1056-1070.

Corredor, L.M., Aliabadian, E., Husein, M., Chen, Z., Maini, B., Sundararaj, U., 2019. Heavy oil recovery by surface modified silica nanoparticle/HPAM nanofluids. Fuel 252, 622-634.

Dong, T., He, S., Chen, M., Hou, Y., Guo, X., Wei, C., Han, Y., Yang, R., 2019. Quartz types and origins in the paleozoic Wufeng-Longmaxi Formations, Eastern Sichuan Basin, China: Implications for porosity preservation in shale reservoirs. Marine and Petroleum Geology 106, 62-73.

Gou, Q., Xu, S., Hao, F., Yang, F., Zhang, B., Shu, Z., Zhang, A., Wang, Y., Lu, Y., Cheng, X., Qing, J., Gao, M., 2019. Full-scale pores and micro-fractures characterization using FE-SEM, gas adsorption, nano-CT and micro-CT: A case study of the Silurian Longmaxi Formation shale in the Fuling area, Sichuan Basin, China. Fuel 253, 167-179.

Han, J., Sun, Y., Guo, W., Li, Q., Deng, S., 2019. Characterization of pyrolysis of Nong’an oil shale at different temperatures and analysis of pyrolysate. Oil Shale 3, 151-170.

Horeh, M.B., Afra, M.J.S., Rostami, B., Ghorbanizadeh, S., 2019. Role of brine composition and water-soluble components of crude oil on the wettability alteration of a carbonate surface. Energy & Fuels 33, 3979-3988.

Ji, L., Lin, M., Cao, G., Jiang, W., 2019. A multiscale reconstructing method for shale based on SEM image and experiment data. Journal of Petroleum Science and Engineering 179, 586-599.

Lai, F.P., Li, Z.P., Dong, H.K., Jiang, Z.Y., Mao, G.T., 2019. Micropore structure characteristics and water distribution in a coalbed methane reservoir. Australian Journal of Earth Sciences 66, 741-750.

Lalla, E., Sanz-Arranz, A., Lopez-Reyes, G., Cote, K., Daly, M., Konstantinidis, M., Rodriguez-Losada, J.A., Groemer, G., Medina, J., Martínez-Frías, J., Rull-Pérez, F., 2019. A micro-Raman and X-ray study of erupted submarine pyroclasts from El Hierro (Spain) and its' astrobiological implications. Life Sciences in Space Research 21, 49-64.

Li, M., Fang, C., Kawasaki, S., Huang, M., Achal, V., 2019. Bio-consolidation of cracks in masonry cement mortars by Acinetobacter sp. SC4 isolated from a karst cave. International Biodeterioration & Biodegradation 141, 94-100.

Liang, F., Zhang, J., Liu, H.-H., Bartko, K.M., 2019. Multiscale experimental studies on interactions between aqueous-based fracturing fluids and tight organic-rich carbonate source rocks. SPE-190325-PA 22, 402-417.

Liu, Q., Sun, Z., Santamarina, J.C., 2019. Transport and adsorption of silica nanoparticles in carbonate reservoirs: A sand column study. Energy & Fuels 33, 4009-4016.


Mitchell, A., Espinosa-Ortiz, E.J., Parks, S.L., Phillips, A.J., Cunningham, A.B., Gerlach, R., 2019. Kinetics of calcite precipitation by ureolytic bacteria under aerobic and anaerobic conditions. Biogeosciences 16, 2147-2161.

Qin, T., Javanbakht, G., Goual, L., 2019. Nanoscale investigation of surfactant-enhanced solubilization of asphaltenes from silicate-rich rocks. Energy & Fuels 33, 3796-3807.

Scholz, V.V., Müller, H., Koren, K., Nielsen, L.P., Meckenstock, R.U., 2019. The rhizosphere of aquatic plants is a habitat for cable bacteria. FEMS Microbiology Ecology 95, Article fiz062.

Song, L., Warner, T., Carr, T., 2019. An efficient, consistent, and trackable method to quantify organic matter–hosted porosity from ion-milled scanning electron microscope images of mudrock gas reservoir. American Association of Petroleum Geologist Bulletin 103, 1473-1492.

Song, S.-B., Liu, J.-F., Yang, D.-S., Ni, H.-Y., Huang, B.-X., Zhang, K., Mao, X.-B., 2019. Pore structure characterization and permeability prediction of coal samples based on SEM images. Journal of Natural Gas Science and Engineering 67, 160-171.



Wu, Y., Misra, S., Sondergeld, C., Curtis, M., Jernigen, J., 2019. Machine learning for locating organic matter and pores in scanning electron microscopy images of organic-rich shales. Fuel 253, 662-676.

Yang, Y., Qiu, L., Wan, M., Jia, X., Cao, Y., Lei, D., Qu, C., 2019. Depositional model for a salinized lacustrine basin: The Permian Lucaogou Formation, Jimsar Sag, Junggar Basin, NW China. Journal of Asian Earth Sciences 178, 81-95.

Zhang, G., Wang, Z., Guo, X., Sun, Y., Sun, L., Pan, L., 2019. Characteristics of lacustrine dolomitic rock reservoir and accumulation of tight oil in the Permian Fengcheng Formation, the western slope of the Mahu Sag, Junggar Basin, NW China. Journal of Asian Earth Sciences 178, 64-80.

Zhang, Y., Zhang, X., Zhong, Q., Hu, S., Mathews, J.P., 2019. Structural differences of spontaneous combustion prone inertinite-rich Chinese lignite coals: Insights from XRD, solid-state 13C NMR, LDIMS, and HRTEM. Energy & Fuels 33, 4575-4584.

Zou, J., Chen, W., Yang, D., Yuan, J., Jiao, Y.-Y., 2019. Fractal characteristics of the anisotropic microstructure and pore distribution of low-rank coal. American Association of Petroleum Geologist Bulletin 103, 1297-1319.

IMAGING: X-RAY CT

Abdelmoula, W.M., Regan, M.S., Lopez, B.G.C., Randall, E.C., Lawler, S., Mladek, A.C., Nowicki, M.O., Marin, B.M., Agar, J.N., Swanson, K.R., Kapur, T., Sarkaria, J.N., Wells, W., Agar, N.Y.R., 2019. Automatic 3D nonlinear registration of mass spectrometry imaging and magnetic resonance imaging data. Analytical Chemistry 91, 6206-6216.

Du, Y., Sang, S., Pan, Z., Wang, W., Liu, S., Fu, C., Zhao, Y., Zhang, J., 2019. Experimental study of supercritical CO2-H2O-coal interactions and the effect on coal permeability. Fuel 253, 369-382.


Lei, L., Seol, Y., Choi, J.-H., Kneafsey, T.J., 2019. Pore habit of methane hydrate and its evolution in sediment matrix – Laboratory visualization with phase-contrast micro-CT. Marine and Petroleum Geology 104, 451-467.

Li, L., Su, Y., Sheng, J.J., Hao, Y., Wang, W., Lv, Y., Zhao, Q., Wang, H., 2019. Experimental and numerical study on CO2 sweep volume during CO2 huff-n-puff enhanced oil recovery process in shale oil reservoirs. Energy & Fuels 33, 4017-4032.

Øren, P.E., Ruspini, L.C., Saadatfar, M., Sok, R.M., Knackstedt, M., Herring, A., 2019. In-situ pore-scale imaging and image-based modelling of capillary trapping for geological storage of CO2. International Journal of Greenhouse Gas Control 87, 34-43.

Xu, Q., Ma, Y., Liu, B., Song, X., Su, J., Chen, Z., 2019. Characteristics and control mechanism of nanoscale pores in lacustrine tight carbonates: Examples from the Jurassic Da'anzhai Member in the central Sichuan Basin, China. Journal of Asian Earth Sciences 178, 156-172.


LIQUID CHROMATOGRAPHY/LC-MS/SFC

Duval, J., Colas, C., Bonnet, P., Lesellier, E., 2019. Hyphenation of ultra-high performance supercritical fluid chromatography with atmospheric pressure chemical ionisation high resolution mass spectrometry: Part 2. Study of chromatographic and mass spectrometry parameters for the analysis of natural non-polar compounds. Journal of Chromatography A 1596, 199-208.

Heiland, J.J., Geissler, D., Piendl, S.K., Warias, R., Belder, D., 2019. Supercritical-fluid chromatography on-chip with two-photon-excited-fluorescence detection for high-speed chiral separations. Analytical Chemistry 91, 6134-6140.

Lam, S.C., Sanz Rodriguez, E., Haddad, P.R., Paull, B., 2019. Recent advances in open tubular capillary liquid chromatography. Analyst 144, 3464-3482.

Lee, J.C., Yang, J.S., Moon, M.H., 2019. Simultaneous relative quantification of various polyglycerophospholipids with isotope-labeled methylation by nanoflow ultrahigh performance liquid chromatography-tandem mass spectrometry. Analytical Chemistry 91, 6716-6723.

Simon, J., Rédei, C., Felinger, A., 2019. The use of alteration analysis in supercritical fluid chromatography to monitor changes in a series of chromatograms. Journal of Chromatography A 1596, 217-225.

Uzhel, A.S., Gorbovskaya, A.V., Zatirakha, A.V., Smolenkov, A.D., Shpigun, O.A., 2019. Manipulating selectivity of covalently-bonded hyperbranched anion exchangers toward organic acids. Part II: Effect of mono- and dicarboxylic amino acids in the internal part of the functional layer. Journal of Chromatography A 1596, 117-123.

Versteegh, G.J.M., Lipp, J., 2019. Detection of new long-chain mid-chain keto-ol isomers from marine sediments by means of HPLC–APCI-MS and comparison with long-chain mid-chain diols from the same samples. Organic Geochemistry 133, 92-102.

Zhou, Y., Zhang, H., Wang, X., Qi, D., Gu, W., Wu, D., Liu, B., 2019. Development of a heart-cutting supercritical fluid chromatography-high-performance liquid chromatography coupled to tandem mass spectrometry for the determination of four

tobacco-specific nitrosamines in mainstream smoke. Analytical and Bioanalytical Chemistry 411, 2961-2969.

MASS SPECTROSCOPY/ICR-FTMS/ORBITRAP

Abdul Jameel, A.G., Khateeb, A., Elbaz, A.M., Emwas, A.-H., Zhang, W., Roberts, W.L., Sarathy, S.M., 2019. Characterization of deasphalted heavy fuel oil using APPI (+) FT-ICR mass spectrometry and NMR spectroscopy. Fuel 253, 950-963.

Ajaero, C., Peru, K.M., Hughes, S.A., Chen, H., McKenna, A.M., Corilo, Y.E., McMartin, D.W., Headley, J.V., 2019. Atmospheric pressure photoionization Fourier transform ion cyclotron resonance mass spectrometry characterization of oil sand process-affected water in constructed wetland treatment. Energy & Fuels 33, 4420-4431.

Baird, M.A., Shliaha, P.V., Anderson, G.A., Moskovets, E., Laiko, V., Makarov, A.A., Jensen, O.N., Shvartsburg, A.A., 2019. High-resolution differential ion mobility separations/Orbitrap mass spectrometry without buffer gas limitations. Analytical Chemistry 91, 6918-6925.

Begum, M.S., Jang, I., Lee, J.-M., Oh, H.B., Jin, H., Park, J.-H., 2019. Synergistic effects of urban tributary mixing on dissolved organic matter biodegradation in an impounded river system. Science of The Total Environment 676, 105-119.

Bierstedt, A., You, Y., van Wasen, S., Bosc-Bierne, G., Weller, M., Riedel, J., 2019. Laser-induced microplasma as an ambient ionization approach for the mass-spectrometric analysis of liquid samples. Analytical Chemistry 91, 5922-5928.

Chen, M., Li, C., Zeng, C., Zhang, F., Raymond, P.A., Hur, J., 2019. Immobilization of relic anthropogenic dissolved organic matter from alpine rivers in the Himalayan-Tibetan Plateau in winter. Water Research 160, 97-106.

Igarza, M., Dittmar, T., Graco, M., Niggemann, J., 2019. Dissolved organic matter cycling in the coastal upwelling system off central Peru during an “El Niño” year. Frontiers in Marine Science 6, 198. doi: 110.3389/fmars.2019.00198.

Nagy, T., Kuki, Á., Nagy, M., Zsuga, M., Kéki, S., 2019. Mass-remainder analysis (MARA): An improved method for elemental composition assignment in petroleomics. Analytical Chemistry 91, 6479-6486.

Phungsai, P., Kurisu, F., Kasuga, I., Furumai, H., 2019. Molecular characteristics of dissolved organic matter transformed by O3 and O3/H2O2 treatments and the effects on formation of unknown disinfection by-products. Water Research 159, 214-222.

Ramírez-Pradilla, J.S., Blanco-Tirado, C., Hubert-Roux, M., Giusti, P., Afonso, C., Combariza, M.Y., 2019. Comprehensive petroporphyrin identification in crude oils using highly selective electron transfer reactions in MALDI-FTICR-MS. Energy & Fuels 33, 3899-3907.

Schwaiger-Haber, M., Hermann, G., El Abiead, Y., Rampler, E., Wernisch, S., Sas, K., Pennathur, S., Koellensperger, G., 2019. Proposing a validation scheme for 13C

metabolite tracer studies in high-resolution mass spectrometry. Analytical and Bioanalytical Chemistry 411, 3103-3113.

Wang, Y., Zhang, Z., Han, L., Sun, K., Jin, J., Yang, Y., Yang, Y., Hao, Z., Liu, J., Xing, B., 2019. Preferential molecular fractionation of dissolved organic matter by iron minerals with different oxidation states. Chemical Geology 520, 69-76.

Xu, M.-L., Wei, X.-Y., Yu, X.-Y., Liu, F.-J., Wu, Q.-C., Li, S., Wang, S.-K., Liu, G.-H., Liu, Z.-Q., Guo, X.-H., Zhang, Y.-Y., Zong, Z.-M., 2019. Insight into molecular compositions of soluble species from sequential thermal dissolution of Liuhuanggou bituminous coal and its extraction residue. Fuel 253, 762-771.

MASS SPECTROSCOPY/OTHER



Gyr, L., Klute, F.D., Franzke, J., Zenobi, R., 2019. Characterization of a nitrogen-based dielectric barrier discharge ionization source for mass spectrometry reveals factors important for soft ionization. Analytical Chemistry 91, 6865-6871.

Kelly, K., Bell, S., Maleki, H., Valentine, S., 2019. Synthetic small molecule characterization and isomer discrimination using gas-phase hydrogen–deuterium exchange IMS-MS. Analytical Chemistry 91, 6259-6265.

Lv, Y., Bai, H., Yang, J., He, Y., Ma, Q., 2019. Direct mass spectrometry analysis using in-capillary dicationic ionic liquid-based in situ dispersive liquid–liquid microextraction and sonic-spray ionization. Analytical Chemistry 91, 6661-6668.

Metarapi, D., Šala, M., Vogel-Mikuš, K., Šelih, V.S., van Elteren, J.T., 2019. Nanoparticle analysis in biomaterials using laser ablation−single particle−inductively coupled plasma mass spectrometry. Analytical Chemistry 91, 6200-6205.

Smets, T., Verbeeck, N., Claesen, M., Asperger, A., Griffioen, G., Tousseyn, T., Waelput, W., Waelkens, E., De Moor, B., 2019. Evaluation of distance metrics and spatial autocorrelation in uniform manifold approximation and projection applied to mass spectrometry imaging data. Analytical Chemistry 91, 5706-5714.

Steyer, D.J., Kennedy, R.T., 2019. High-throughput nanoelectrospray ionization-mass spectrometry analysis of microfluidic droplet samples. Analytical Chemistry 91, 6645-6651.

Tamara, S., Hoek, M., Scheltema, R.A., Leney, A.C., Heck, A.J.R., 2019. A colorful pallet of B-phycoerythrin proteoforms exposed by a multimodal mass spectrometry approach. Chem 5, 1302-1317.

Tao, Y., Huang, X., Gao, D., Wang, X., Chen, C., Liang, H., van Loosdrecht, M.C.M., 2019. NanoSIMS reveals unusual enrichment of acetate and propionate by an anammox consortium dominated by Jettenia asiatica. Water Research 159, 223-232.

Trimpin, S., Inutan, E.D., Karki, S., Elia, E.A., Zhang, W.-J., Weidner, S.M., Marshall, D.D., Hoang, K., Lee, C., Davis, E.T.J., Smith, V., Meher, A.K., Cornejo, M.A., Auner, G.W., McEwen, C.N., 2019. Fundamental studies of new ionization technologies and insights from IMS-MS. Journal of The American Society for Mass Spectrometry 30, 1133-1147.

Zhang, Y., Zhao, W., Wang, D., Zhang, H., Chai, G., Zhang, Q., Lu, B., Sun, S., Zhang, J., 2019. Direct analysis of carbonyl compounds by mass spectrometry with double-region atmospheric pressure chemical ionization. Analytical Chemistry 91, 5715-5721.

Zhao, Z.-Y., Qin, L., Huang, X.-H., Zhang, Y.-Y., Du, M., Xu, X.-B., Zhou, D.-Y., Zhu, B.-W., 2019. Coated direct inlet probe coupled with atmospheric-pressure chemical ionization and high-resolution mass spectrometry for fast quantitation of target analytes. Journal of Chromatography A 1596, 20-29.

METABOLOMICS/LIPIDOMICS

Bijlsma, L., Berntssen, M.H.G., Merel, S., 2019. A refined nontarget workflow for the investigation of metabolites through the prioritization by in silico prediction tools. Analytical Chemistry 91, 6321-6328.

Blachowicz, A., Chiang, A.J., Elsaesser, A., Kalkum, M., Ehrenfreund, P., Stajich, J.E., Torok, T., Wang, C.C.C., Venkateswaran, K., 2019. Proteomic and metabolomic characteristics of extremophilic fungi under simulated Mars conditions. Frontiers in Microbiology 10, 1013. doi: 1010.3389/fmicb.2019.01013.

Blevins, M.S., Klein, D.R., Brodbelt, J.S., 2019. Localization of cyclopropane modifications in bacterial lipids via 213 nm ultraviolet photodissociation mass spectrometry. Analytical Chemistry 91, 6820-6828.

Frick, A.A., Weyermann, C., 2019. An untargeted lipidomic approach for qualitative determination of latent fingermark glycerides using UPLC-IMS-QToF-MSE. Analyst 144, 3590-3600.

Geiger, O. (Ed.), 2019. Biogenesis of Fatty Acids, Lipids and Membranes, Handbook of Hydrocarbon and Lipid Microbiology. Springer, Cham, 886 pp.

Ji, H., Xu, Y., Lu, H., Zhang, Z., 2019. Deep MS/MS-aided structural-similarity scoring for unknown metabolite identification. Analytical Chemistry 91, 5629-5637.


Kitamura, S., Toya, Y., Shimizu, H., 2019. 13C-metabolic flux analysis reveals effect of phenol on central carbon metabolism in Escherichia coli. Frontiers in Microbiology 10, 1010. doi: 1010.3389/fmicb.2019.01010.

Liu, W., Song, Q., Cao, Y., Zhao, Y., Huo, H., Wang, Y., Song, Y., Li, J., Tu, P., 2019. Advanced liquid chromatography-mass spectrometry enables merging widely targeted metabolomics and proteomics. Analytica Chimica Acta 1069, 89-97.

Liu, Z., Portero, E.P., Jian, Y., Zhao, Y., Onjiko, R.M., Zeng, C., Nemes, P., 2019. Trace, machine learning of signal images for trace-sensitive mass spectrometry: A case study from single-cell metabolomics. Analytical Chemistry 91, 5768-5776.

Schwaiger-Haber, M., Hermann, G., El Abiead, Y., Rampler, E., Wernisch, S., Sas, K., Pennathur, S., Koellensperger, G., 2019. Proposing a validation scheme for 13C metabolite tracer studies in high-resolution mass spectrometry. Analytical and Bioanalytical Chemistry 411, 3103-3113.

Zheng, J., Zheng, S.-J., Cai, W.-J., Yu, L., Yuan, B.-F., Feng, Y.-Q., 2019. Stable isotope labeling combined with liquid chromatography-tandem mass spectrometry for comprehensive analysis of short-chain fatty acids. Analytica Chimica Acta 1070, 51-59.

Zhu, Q.-F., Zhang, T.-Y., Qin, L.-L., Li, X.-M., Zheng, S.-J., Feng, Y.-Q., 2019. Method to calculate the retention index in hydrophilic interaction liquid chromatography using normal fatty acid derivatives as calibrants. Analytical Chemistry 91, 6057-6063.

PUPPYOMICS

Fall, T., Kuja-Halkola, R., Dobney, K., Westgarth, C., Magnusson, P.K.E., 2019. Evidence of large genetic influences on dog ownership in the Swedish Twin Registry has implications for understanding domestication and health associations. Scientific Reports 9, Article 7554.

Archaeological/Art Organic Chemistry

Delile, H., Pleuger, E., Blichert-Toft, J., Goiran, J.-P., Fagel, N., Gadhoum, A., Abichou, A., Ben Jerbania, I., Fentress, E., Wilson, A.I., 2019. Economic resilience of Carthage during the Punic Wars: Insights from sediments of the Medjerda delta around Utica (Tunisia). Proceedings of the National Academy of Sciences 116, 9764-9769.

Dunne, J., Chapman, A., Blinkhorn, P., Evershed, R.P., 2019. Reconciling organic residue analysis, faunal, archaeobotanical and historical records: Diet and the medieval peasant at West Cotton, Raunds, Northamptonshire. Journal of Archaeological Science 107, 58-70.

Hao, X., Schilling, M.R., Wang, X., Khanjian, H., Heginbotham, A., Han, J., Auffret, S., Wu, X., Fang, B., Tong, H., 2019. Use of THM-PY-GC/MS technique to characterize complex, multilayered Chinese lacquer. Journal of Analytical and Applied Pyrolysis 140, 339-348.

Kashuba, N., Kırdök, E., Damlien, H., Manninen, M.A., Nordqvist, B., Persson, P., Götherström, A., 2019. Ancient DNA from mastics solidifies connection between material culture and

genetics of mesolithic hunter–gatherers in Scandinavia. Communications Biology 2, Article 185.

Kaushal, R., Ghosh, P., Pokharia, A.K., 2019. Stable isotopic composition of rice grain organic matter marking an abrupt shift of hydroclimatic condition during the cultural transformation of Harappan civilization. Quaternary International 512, 144-154.

Metcalfe, J.Z., Mead, J.I., 2019. Do uncharred plants preserve original carbon and nitrogen isotope compositions? Journal of Archaeological Method and Theory 26, 844-872.

Sánchez-Quinto, F., Malmström, H., Fraser, M., Girdland-Flink, L., Svensson, E.M., Simões, L.G., George, R., Hollfelder, N., Burenhult, G., Noble, G., Britton, K., Talamo, S., Curtis, N., Brzobohata, H., Sumberova, R., Götherström, A., Storå, J., Jakobsson, M., 2019. Megalithic tombs in western and northern Neolithic Europe were linked to a kindred society. Proceedings of the National Academy of Sciences 116, 9469-9474.

Scarcelli, N., Cubry, P., Akakpo, R., Thuillet, A.-C., Obidiegwu, J., Baco, M.N., Otoo, E., Sonké, B., Dansi, A., Djedatin, G., Mariac, C., Couderc, M., Causse, S., Alix, K., Chaïr, H., François, O., Vigouroux, Y., 2019. Yam genomics supports West Africa as a major cradle of crop domestication. Science Advances 5, Article eaaw1947.

Schroeder, H., Margaryan, A., Szmyt, M., Theulot, B., Włodarczak, P., Rasmussen, S., Gopalakrishnan, S., Szczepanek, A., Konopka, T., Jensen, T.Z.T., Witkowska, B., Wilk, S., Przybyła, M.M., Pospieszny, Ł., Sjögren, K.-G., Belka, Z., Olsen, J., Kristiansen, K., Willerslev, E., Frei, K.M., Sikora, M., Johannsen, N.N., Allentoft, M.E., 2019. Unraveling ancestry, kinship, and violence in a Late Neolithic mass grave. Proceedings of the National Academy of Sciences 116, 10705-10710.

van der Sluis, L.G., Reimer, P.J., Ogle, N., 2019. Adding hydrogen to the isotopic inventory—Combining δ13C, δ15N and δ2H stable isotope analysis for palaeodietary purposes on archaeological bone. Archaeometry 61, 720-749.

Yoneda, M., Kisida, K., Gakuhari, T., Omori, T., Abe, Y., 2019. Interpretation of bulk nitrogen and carbon isotopes in archaeological foodcrusts on potsherds. Rapid Communications in Mass Spectrometry 33, 1097-1106.

Biochemistry

Brumley, D.R., Carrara, F., Hein, A.M., Yawata, Y., Levin, S.A., Stocker, R., 2019. Bacteria push the limits of chemotactic precision to navigate dynamic chemical gradients. Proceedings of the National Academy of Sciences 116, 10792-10797.

Geiger, O., 2019. Biogenesis of Fatty Acids, Lipids and Membranes, Handbook of Hydrocarbon and Lipid Microbiology. Springer, Cham, p. 886.

Kawai, S., Kamiya, N., Matsuura, K., Haruta, S., 2019. Symbiotic growth of a thermophilic sulfide-oxidizing photoautotroph and an elemental sulfur-disproportionating chemolithoautotroph and cooperative dissimilatory oxidation of sulfide to sulfate. Frontiers in Microbiology 10, 1150. doi: 1110.3389/fmicb.2019.01150.

Liu, C., Mao, L., Zheng, X., Yuan, J., Hu, B., Cai, Y., Xie, H., Peng, X., Ding, X., 2019. Comparative proteomic analysis of Methanothermobacter thermautotrophicus reveals methane formation from H2 and CO2 under different temperature conditions. MicrobiologyOpen 8, e00715.

Ross, M.O., MacMillan, F., Wang, J., Nisthal, A., Lawton, T.J., Olafson, B.D., Mayo, S.L., Rosenzweig, A.C., Hoffman, B.M., 2019. Particulate methane monooxygenase contains only mononuclear copper centers. Science 364, 566-570.

Shah, V., Zhao, X., Lundeen, R.A., Ingalls, A.E., Nicastro, D., Morris, R.M., 2019. Morphological plasticity in a sulfur-oxidizing marine bacterium from the SUP05 clade enhances dark carbon fixation. mBio 10, Article e00216-00219.


Biodegradation

Mehetre, G.T., Dastager, S.G., Dharne, M.S., 2019. Biodegradation of mixed polycyclic aromatic hydrocarbons by pure and mixed cultures of biosurfactant producing thermophilic and thermo-tolerant bacteria. Science of The Total Environment 679, 52-60.

Raddadi, N., Fava, F., 2019. Biodegradation of oil-based plastics in the environment: Existing knowledge and needs of research and innovation. Science of The Total Environment 679, 148-158.

Sabar, M.A., Ali, M.I., Fatima, N., Malik, A.Y., Jamal, A., Farman, M., Huang, Z., Urynowicz, M., 2019. Degradation of low rank coal by Rhizopus oryzae isolated from a Pakistani coal mine and its enhanced releases of organic substances. Fuel 253, 257-265.

Schreiber, L., Fortin, N., Tremblay, J., Wasserscheid, J., Elias, M., Mason, J., Sanschagrin, S., Cobanli, S., King, T., Lee, K., Greer, C.W., 2019. Potential for microbially mediated natural attenuation of diluted bitumen on the coast of British Columbia (Canada). Applied and Environmental Microbiology 85, Article e00086-00019.

Socolofsky, S.A., Gros, J., North, E., Boufadel, M.C., Parkerton, T.F., Adams, E.E., 2019. The treatment of biodegradation in models of sub-surface oil spills: A review and sensitivity study. Marine Pollution Bulletin 143, 204-219.

Song, B., Tang, J., Zhen, M., Liu, X., 2019. Effect of rhamnolipids on enhanced anaerobic degradation of petroleum hydrocarbons in nitrate and sulfate sediments. Science of The Total Environment 678, 438-447.

Steinmetz, Z., Kurtz, M.P., Zubrod, J.P., Meyer, A.H., Elsner, M., Schaumann, G.E., 2019. Biodegradation and photooxidation of phenolic compounds in soil—A compound-specific stable isotope approach. Chemosphere 230, 210-218.

Wang, C.-C., Li, C.-H., Yang, C.-F., 2019. Acclimated methanotrophic consortia for aerobic co-metabolism of trichloroethene with methane. International Biodeterioration & Biodegradation 142, 52-57.

BIODEGRADATION PATHWAYS/GENOMICS

Ali, F., Hu, H., Wang, W., Zhou, Z., Shah, S.B., Xu, P., Tang, H., 2019. Characterization of a dibenzofuran-degrading strain of Pseudomonas aeruginosa, FA-HZ1. Environmental Pollution 250, 262-273.

Elhusseiny, S.M., Amin, H.M., Shebl, R.I., 2019. Modulation of laccase transcriptome during biodegradation of naphthalene by white rot fungus Pleurotus ostreatus. International Microbiology 22, 217-225.

James, K.L., Kung, J.W., Crable, B.R., Mouttaki, H., Sieber, J.R., Nguyen, H.H., Yang, Y., Xie, Y., Erde, J., Wofford, N.Q., Karr, E.A., Loo, J.A., Ogorzalek Loo, R.R., Gunsalus, R.P., McInerney, M.J., 2019. Syntrophus aciditrophicus uses the same enzymes in a reversible manner to degrade and synthesize aromatic and alicyclic acids. Environmental Microbiology 21, 1833-1846.


Koelschbach, J.S., Mouttaki, H., Merl-Pham, J., Arnold, M.E., Meckenstock, R.U., 2019. Identification of naphthalene carboxylase subunits of the sulfate-reducing culture N47. Biodegradation 30, 147-160.

Peng, C., Huang, D., Shi, Y., Zhang, B., Sun, L., Li, M., Deng, X., Wang, W., 2019. Comparative transcriptomic analysis revealed the key pathways responsible for organic sulfur removal by thermophilic bacterium Geobacillus thermoglucosidasius W-2. Science of The Total Environment 676, 639-650.

Rossmassler, K., Snow, C.D., Taggart, D., Brown, C., De Long, S.K., 2019. Advancing biomarkers for anaerobic o-xylene biodegradation via metagenomic analysis of a methanogenic consortium. Applied Microbiology and Biotechnology 103, 4177-4192.

Schlüter, R., Dallinger, A., Kabisch, J., Duldhardt, I., Schauer, F., 2019. Fungal biotransformation of short-chain n-alkylcycloalkanes. Applied Microbiology and Biotechnology 103, 4137-4151.

Wang, X., Xu, P., 2019. Microbial degradation of nitrogen heterocycles. International Biodeterioration & Biodegradation 142, 170-171.

Biofuels/Biomass/Bioengineering

Bhatia, S.K., Gurav, R., Choi, T.-R., Han, Y.H., Park, Y.-L., Jung, H.-R., Yang, S.-Y., Song, H.-S., Yang, Y.-H., 2019. A clean and green approach for odd chain fatty acids production in Rhodococcus sp. YHY01 by medium engineering. Bioresource Technology 286, 121383.

Brandon, A.M., Criddle, C.S., 2019. Can biotechnology turn the tide on plastics? Current Opinion in Biotechnology 57, 160-166.

Chaudhary, R., Dhepe, P.L., 2019. Depolymerization of lignin using a solid base catalyst. Energy & Fuels 33, 4369-4377.

Chellamuthu, P., Naughton, K., Pirbadian, S., Silva, K.P.T., Chavez, M.S., El-Naggar, M.Y., Boedicker, J., 2019. Biogenic control of manganese doping in zinc sulfide nanomaterial using Shewanella oneidensis MR-1. Frontiers in Microbiology 10, 938. doi: 910.3389/fmicb.2019.00938.

Dodge, L.A., Kalinoski, R.M., Das, L., Bursavich, J., Muley, P., Boldor, D., Shi, J., 2019. Sequential extraction and characterization of lignin-derived compounds from thermochemically processed biorefinery lignins. Energy & Fuels 33, 4322-4330.

González Martínez, M., Ohra-aho, T., Tamminen, T., da Silva Perez, D., Campargue, M., Dupont, C., 2019. Detailed structural elucidation of different lignocellulosic biomass types using optimized temperature and time profiles in fractionated Py-GC/MS. Journal of Analytical and Applied Pyrolysis 140, 112-124.

Khan, S., Kay Lup, A.N., Qureshi, K.M., Abnisa, F., Wan Daud, W.M.A., Patah, M.F.A., 2019. A review on deoxygenation of triglycerides for jet fuel range hydrocarbons. Journal of Analytical and Applied Pyrolysis 140, 1-24.

Kim, E.J., Jung, W., Lim, S., Kim, S., Choi, H.-G., Han, S.J., 2019. Lipid production by arctic microalga Chlamydomonas sp. KNF0008 at low temperatures. Applied Biochemistry and Biotechnology 188, 326-337.

Liu, G., Qu, Y., 2019. Engineering of filamentous fungi for efficient conversion of lignocellulose: Tools, recent advances and prospects. Biotechnology Advances 37, 519-529.

Nagappan, S., Devendran, S., Tsai, P.-C., Dinakaran, S., Dahms, H.-U., Ponnusamy, V.K., 2019. Passive cell disruption lipid extraction methods of microalgae for biofuel production – A review. Fuel 252, 699-709.

Omar, B., El-Gammal, M., Abou-Shanab, R., Fotidis, I.A., Angelidaki, I., Zhang, Y., 2019. Biogas upgrading and biochemical production from gas fermentation: Impact of microbial community and gas composition. Bioresource Technology 286, 121413.

Pang, S., 2019. Advances in thermochemical conversion of woody biomass to energy, fuels and chemicals. Biotechnology Advances 37, 589-597.

Papanikolaou, S., Aggelis, G., 2019. Sources of microbial oils with emphasis to Mortierella (Umbelopsis) isabellina fungus. World Journal of Microbiology and Biotechnology 35, Article 63.

Priharto, N., Ronsse, F., Prins, W., Hita, I., Deuss, P.J., Heeres, H.J., 2019. Hydrotreatment of pyrolysis liquids derived from second-generation bioethanol production residues over NiMo and CoMo catalysts. Biomass and Bioenergy 126, 84-93.

Pugazhendhi, A., Mathimani, T., Varjani, S., Rene, E.R., Kumar, G., Kim, S.-H., Ponnusamy, V.K., Yoon, J.-J., 2019. Biobutanol as a promising liquid fuel for the future - recent updates and perspectives. Fuel 253, 637-646.

Silva, T.R., Tavares, R.S.N., Canela-Garayoa, R., Eras, J., Rodrigues, M.V.N., Neri-Numa, I.A., Pastore, G.M., Rosa, L.H., Schultz, J.A.A., Debonsi, H.M., Cordeiro, L.R.G., Oliveira, V.M.,

2019. Chemical characterization and biotechnological applicability of pigments isolated from Antarctic bacteria. Marine Biotechnology 21, 416-429.

Westbrook, A.W., Miscevic, D., Kilpatrick, S., Bruder, M.R., Moo-Young, M., Chou, C.P., 2019. Strain engineering for microbial production of value-added chemicals and fuels from glycerol. Biotechnology Advances 37, 538-568.

Yang, X., Zhao, Y., Li, W., Li, R., Wu, Y., 2019. Unveiling the pyrolysis mechanisms of hemicellulose: Experimental and theoretical studies. Energy & Fuels 33, 4352-4360.

Yang, Z., Zhang, Z., 2019. Recent advances on production of 2, 3-butanediol using engineered microbes. Biotechnology Advances 37, 569-578.

Zeng, A.-P., 2019. New bioproduction systems for chemicals and fuels: Needs and new development. Biotechnology Advances 37, 508-518.

Biogeochemistry

Berg, J.S., Pjevac, P., Sommer, T., Buckner, C.R.T., Philippi, M., Hach, P.F., Liebeke, M., Holtappels, M., Danza, F., Tonolla, M., Sengupta, A., Schubert, C.J., Milucka, J., Kuypers, M.M.M., 2019. Dark aerobic sulfide oxidation by anoxygenic phototrophs in anoxic waters. Environmental Microbiology 21, 1611-1626.

D′Acunha, B., Morillas, L., Black, T.A., Christen, A., Johnson, M.S., 2019. Net ecosystem carbon balance of a peat bog undergoing restoration: Integrating CO2 and CH4 fluxes from eddy covariance and aquatic evasion with DOC drainage fluxes. Journal of Geophysical Research: Biogeosciences 124, 884-901.

Dean, J.F., 2019. Groundwater dependent ecosystems in arid zones can use ancient subterranean carbon as an energy source in the local food web. Journal of Geophysical Research: Biogeosciences 124, 733-736.

Ehrnsten, E., Norkko, A., Timmermann, K., Gustafsson, B.G., 2019. Benthic-pelagic coupling in coastal seas – Modelling macrofaunal biomass and carbon processing in response to organic matter supply. Journal of Marine Systems 196, 36-47.

Fein, J.B., Yu, Q., Nam, J., Yee, N., 2019. Bacterial cell envelope and extracellular sulfhydryl binding sites: Their roles in metal binding and bioavailability. Chemical Geology 521, 28-38.

Gar’kusha, D.N., Fedorov, Y.A., Andreev, Y.A., Tambieva, N.S., Mikhailenko, O.A., 2019. Methane and sulfide sulfur in the bottom sediments of Lake Baikal. Geochemistry International 57, 466-479.

Gerardo-Nieto, O., Vega-Peñaranda, A., Gonzalez-Valencia, R., Alfano-Ojeda, Y., Thalasso, F., 2019. Continuous measurement of diffusive and ebullitive fluxes of methane in aquatic ecosystems by an open dynamic chamber method. Environmental Science & Technology 53, 5159-5167.

Johnson, C.R., Fein, J.B., 2019. A mechanistic study of Au(III) removal from solution by Bacillus subtilis. Geomicrobiology Journal 36, 506-514.


Kwon, M.J., Jung, J.Y., Tripathi, B.M., Göckede, M., Lee, Y.K., Kim, M., 2019. Dynamics of microbial communities and CO2 and CH4 fluxes in the tundra ecosystems of the changing Arctic. Journal of Microbiology 57, 325-336.


Liu, X., Chu, G., Du, Y., Li, J., Si, Y., 2019. The role of electron shuttle enhances Fe(III)-mediated reduction of Cr(VI) by Shewanella oneidensis MR-1. World Journal of Microbiology and Biotechnology 35, Article 64.

Lynch, K.L., Jackson, W.A., Rey, K., Spear, J.R., Rosenzweig, F., Munakata-Marr, J., 2019. Evidence for biotic perchlorate reduction in naturally perchlorate-rich sediments of Pilot Valley Basin, Utah. Astrobiology 19, 629-641.

Ma, S., Tong, M., Yuan, S., Liu, H., 2019. Responses of the microbial community structure in Fe(II)-bearing sediments to oxygenation: The role of reactive oxygen species. ACS Earth and Space Chemistry 3, 738-747.

Meyer-Dombard, D.A.R., Osburn, M.R., Cardace, D., Arcilla, C.A., 2019. The effect of a tropical climate on available nutrient resources to springs in ophiolite-hosted, deep biosphere ecosystems in the Philippines. Frontiers in Microbiology 10, 761. doi: 710.3389/fmicb.2019.00761.

Monachon, M., Albelda-Berenguer, M., Joseph, E., 2019. Biological oxidation of iron sulfides. Advances in Applied Microbiology 107, 1-27.

Naafs, B.D.A., Inglis, G.N., Blewett, J., McClymont, E.L., Lauretano, V., Xie, S., Evershed, R.P., Pancost, R.D., 2019. The potential of biomarker proxies to trace climate, vegetation, and biogeochemical processes in peat: A review. Global and Planetary Change 179, 57-79.

Parro, V., Puente-Sánchez, F., Cabrol, N.A., Gallardo-Carreño, I., Moreno-Paz, M., Blanco, Y., García-Villadangos, M., Tambley, C., Tilot, V.C., Thompson, C., Smith, E., Sobrón, P., Demergasso, C.S., Echeverría-Vega, A., Fernández-Martínez, M.Á., Whyte, L.G., Fairén, A.G., 2019. Microbiology and nitrogen cycle in the benthic sediments of a glacial oligotrophic deep Andean lake as analog of ancient martian lake-beds. Frontiers in Microbiology 10, 929. doi: 910.3389/fmicb.2019.00929.

Soares, A.R.A., Berggren, M., 2019. Indirect link between riverine dissolved organic matter and bacterioplankton respiration in a boreal estuary. Marine Environmental Research 148, 39-45.

Sudirjo, E., Buisman, C.J.N., Strik, D.P.B.T.B., 2019. Marine sediment mixed with activated carbon allows electricity production and storage from internal and external energy sources: A new rechargeable bio-battery with bi-directional electron transfer properties. Frontiers in Microbiology 10, 934. doi: 910.3389/fmicb.2019.00934.

Wakeham, S.G., Lee, C., 2019. Limits of our knowledge, part 2: Selected frontiers in marine organic biogeochemistry. Marine Chemistry 212, 16-46.

Zhan, Y., Yang, M., Zhang, S., Zhao, D., Duan, J., Wang, W., Yan, L., 2019. Iron and sulfur oxidation pathways of Acidithiobacillus ferrooxidans. World Journal of Microbiology and Biotechnology Article 35, 60.

Zhang, J., Kattner, G., Koch, B.P., 2019. Interactions of trace elements and organic ligands in seawater and implications for quantifying biogeochemical dynamics: A review. Earth-Science Reviews 192, 631-649.

Zhang, W., Zhou, Y., Jeppesen, E., Wang, L., Tan, H., Zhang, J., 2019. Linking heterotrophic bacterioplankton community composition to the optical dynamics of dissolved organic matter in a large eutrophic Chinese lake. Science of The Total Environment 679, 136-147.

Zhang, X., Liu, K., Li, P., Jiao, J.J.J., Dvornyk, V., Gu, J.-D., 2019. Molecular existence and diversity of nitrite-dependent anaerobic methane oxidizing (n-damo) bacteria in the lakes of Badain of the Gobi Desert. Geomicrobiology Journal 36, 522-532.

BIOFILM/MICROBIAL INDUCED CORROSION

Antunes, J., Leão, P., Vasconcelos, V., 2019. Marine biofilms: diversity of communities and of chemical cues. Environmental Microbiology Reports 11, 287-305.

Chen, S., Deng, H., Liu, G., Zhang, D., 2019. Corrosion of Q235 carbon steel in seawater containing Mariprofundus ferrooxydans and Thalassospira sp. Frontiers in Microbiology 10, 936. doi: 910.3389/fmicb.2019.00936.

Guo, Z., Pan, S., Liu, T., Zhao, Q., Wang, Y., Guo, N., Chang, X., Liu, T., Dong, Y., Yin, Y., 2019. Bacillus subtilis inhibits Vibrio natriegens-induced corrosion via biomineralization in seawater. Frontiers in Microbiology 10, 1111. doi: 1110.3389/fmicb.2019.01111.

Herrling, M.P., Lackner, S., Nirschl, H., Horn, H., Guthausen, G., 2019. Recent NMR/MRI studies of biofilm structures and dynamics, in: Webb, G.A. (Ed.), Annual Reports on NMR Spectroscopy. Academic Press, pp. 163-213.

Perin, G., Jones, P.R., 2019. Economic feasibility and long-term sustainability criteria on the path to enable a transition from fossil fuels to biofuels. Current Opinion in Biotechnology 57, 175-182.


MICROBIAL MEDIATION OF MINERAL FORMATION/DEGRADATION

Bontognali, T.R.R., 2019. Anoxygenic phototrophs and the forgotten art of making dolomite. Geology 47, 591-592.

Daye, M., Higgins, J., Bosak, T., 2019. Formation of ordered dolomite in anaerobic photosynthetic biofilms. Geology 47, 509-512.

Kim, J., Dong, H., Yang, K., Park, H., Elliott, W.C., Spivack, A., Koo, T.-h., Kim, G., Morono, Y., Henkel, S., Inagaki, F., Zeng, Q., Hoshino, T., Heuer, V.B., 2019. Naturally occurring, microbially induced smectite-to-illite reaction. Geology 47, 535-539.



Rea, M.A., Shuster, J., Hoffmann, V.E., Schade, M., Bissett, A., Reith, F., 2019. Does the primary deposit affect the biogeochemical transformation of placer gold and associated biofilms? Gondwana Research 73, 77-95.

Tamayo-Figueroa, D.P., Castillo, E., Brandão, P.F.B., 2019. Metal and metalloid immobilization by microbiologically induced carbonates precipitation. World Journal of Microbiology and Biotechnology 35, Article 58.

Tong, H., Feng, D., Peckmann, J., Roberts, H.H., Chen, L., Bian, Y., Chen, D., 2019. Environments favoring dolomite formation at cold seeps: A case study from the Gulf of Mexico. Chemical Geology 518, 9-18.

Wang, T., Tian, Z., Tunlid, A., Persson, P., 2019. Influence of ammonium on formation of mineral-associated organic carbon by an ectomycorrhizal fungus. Applied and Environmental Microbiology 85, Article e03007-03018.

Carbon Cycle

Bradbury, H.J., Turchyn, A.V., 2019. Reevaluating the carbon sink due to sedimentary carbonate formation in modern marine sediments. Earth and Planetary Science Letters 519, 40-49.

Cao, S., Neubauer, F., 2019. Graphitic material in fault zones: Implications for fault strength and carbon cycle. Earth-Science Reviews 194, 109-124.

Cuellar-Martinez, T., Ruiz-Fernández, A.C., Sanchez-Cabeza, J.-A., Pérez-Bernal, L.-H., Sandoval-Gil, J., 2019. Relevance of carbon burial and storage in two contrasting blue carbon ecosystems of a north-east Pacific coastal lagoon. Science of The Total Environment 675, 581-593.

Farmer, J.R., Hönisch, B., Haynes, L.L., Kroon, D., Jung, S., Ford, H.L., Raymo, M.E., Jaume-Seguí, M., Bell, D.B., Goldstein, S.L., Pena, L.D., Yehudai, M., Kim, J., 2019. Deep Atlantic Ocean carbon storage and the rise of 100,000-year glacial cycles. Nature Geoscience 12, 355-360.

Jeltsch-Thömmes, A., Battaglia, G., Cartapanis, O., Jaccard, S.L., Joos, F., 2019. Low terrestrial carbon storage at the Last Glacial Maximum: constraints from multi-proxy data. Climate of the Past 15, 849-879.

Smeaton, C., Cui, X., Bianchi, T.S., Cage, A.G., Howe, J.A., Austin, W.E.N., 2019. The Holocene evolution of a sedimentary carbon store in a mid latitude fjord. Biogeosciences Discussions 2019, 1-31.

Climate ChangeTuretsky, M.R., Abbott, B.W., Jones, M.C., Anthony, K.W., Olefeldt, D., Schuur, E.A.G.,

Koven, C., McGuire, A.D., Grosse, G., Kuhry, P., Hugelius, G., Lawrence, D.M., Gibson, C., Sannel , A.B.K., 2019. Permafrost collapse is accelerating carbon release. Nature Astronomy 569, 32-34.

Wild, B., Andersson, A., Bröder, L., Vonk, J., Hugelius, G., McClelland, J.W., Song, W., Raymond, P.A., Gustafsson, Ö., 2019. Rivers across the Siberian Arctic unearth the patterns of carbon release from thawing permafrost. Proceedings of the National Academy of Sciences 116, 10280-10285.

Carbon Sequestration

Bihani, A., Daigle, H., 2019. On the role of spatially correlated heterogeneity in determining mudrock sealing capacity for CO2 sequestration. Marine and Petroleum Geology 106, 116-127.

Dance, T., LaForce, T., Glubokovskikh, S., Ennis-King, J., Pevzner, R., 2019. Illuminating the geology: Post-injection reservoir characterisation of the CO2CRC Otway site. International Journal of Greenhouse Gas Control 86, 146-157.

Esene, C., Zendehboudi, S., Aborig, A., Shiri, H., 2019. A modeling strategy to investigate carbonated water injection for EOR and CO2 sequestration. Fuel 252, 710-721.

Huan, T.N., Dalla Corte, D.A., Lamaison, S., Karapinar, D., Lutz, L., Menguy, N., Foldyna, M., Turren-Cruz, S.-H., Hagfeldt, A., Bella, F., Fontecave, M., Mougel, V., 2019. Low-cost high-efficiency system for solar-driven conversion of CO2 to hydrocarbons. Proceedings of the National Academy of Sciences 116, 9735-9740.

Jiang, Y., Chu, N., Zhang, W., Ma, J., Zhang, F., Liang, P., Zeng, R.J., 2019. Zinc: A promising material for electrocatalyst-assisted microbial electrosynthesis of carboxylic acids from carbon dioxide. Water Research 159, 87-94.

Ju, Y., Beaubien, S.E., Lee, S.-S., Kaown, D., Hahm, D., Lee, S., Park, I.-W., Park, K., Yun, S.-T., Lee, K.-K., 2019. Application of natural and artificial tracers to constrain CO2 leakage and degassing in the K-COSEM site, South Korea. International Journal of Greenhouse Gas Control 86, 211-225.

Li, P., Yi, L., Liu, X., Hu, G., Lu, J., Zhou, D., Hovorka, S., Liang, X., 2019. Screening and simulation of offshore CO2-EOR and storage: A case study for the HZ21-1 oilfield in the

Pearl River Mouth Basin, Northern South China Sea. International Journal of Greenhouse Gas Control 86, 66-81.

Li, Z., Elsworth, D., 2019. Controls of CO2–N2 gas flood ratios on enhanced shale gas recovery and ultimate CO2 sequestration. Journal of Petroleum Science and Engineering 179, 1037-1045.


Shao, H., Ussiri, D.A.N., Patterson, C.G., Locke, R.A., Wang, H., Taylor, A.H., Cohen, H.F., 2019. Soil gas monitoring at the Illinois Basin – Decatur Project carbon sequestration site. International Journal of Greenhouse Gas Control 86, 112-124.

Wen, G., Benson, S.M., 2019. CO2 plume migration and dissolution in layered reservoirs. International Journal of Greenhouse Gas Control 87, 66-79.

Coal/Lignite/Peat Geochemistry

Chang, H., Zhang, Z., Qiang, L., Gao, T., Lan, T., Sun, M., Xu, L., Ma, X., 2019. Study on the pyrolysis characteristics of a typical low rank coal with hydrothermal pretreatment. Energy & Fuels 33, 3871-3880.


Dong, L., Han, S., Yu, W., Lei, Z., Kang, S., Zhang, K., Yan, J., Li, Z., Shui, H., Wang, Z., Ren, S., Pan, C., 2019. Effect of volatile reactions on the yield and quality of tar from pyrolysis of Shenhua bituminous coal. Journal of Analytical and Applied Pyrolysis 140, 321-330.

Fan, C., Li, S., Luo, M., Zhou, L., Zhang, H., Yang, Z., 2019. Effects of N and S functionalities on binary gas co-adsorption on a coal macromolecule. Energy & Fuels 33, 3934-3946.

He, D., Huang, H., Arismendi, G.G., 2019. n-Alkane distribution in ombrotrophic peatlands from the northeastern Alberta, Canada, and its paleoclimatic implications. Palaeogeography, Palaeoclimatology, Palaeoecology 528, 247-257.


Lv, J.-H., Wei, X.-Y., Zhang, Y.-Y., Zong, Z.-M., 2019. Structural characterization of Baiyinhua lignite via direct and thermal decomposition methods. Fuel 253, 1042-1047.


Rajak, P.K., Singh, V.K., Singh, P.K., 2019. Distribution of inertinites in the Early Paleogene lignites of western India: On the possibility of wildfire activities. Journal of the Geological Society of India 93, 523-532.



Yang, Y., Liao, J., Mo, Q., Chang, L., Bao, W., 2019. Evolution of physical and chemical structures in lignite during dewatering process and their effects on combustion reactivity. Energy & Fuels 33, 3891-3898.


Zheng, M., Li, X., Wang, M., Guo, L., 2019. Dynamic profiles of tar products during Naomaohu coal pyrolysis revealed by large-scale reactive molecular dynamic simulation. Fuel 253, 910-920.

Zhou, G., Wei, G., Hu, G., 2019. The geochemical and organic petrological characteristics of coal measures of the Xujiahe formation in the Sichuan Basin, China. Energy Exploration & Exploitation 37, 889-906.


COAL BED METHANE

Chen, G., Fan, Y., Li, Q., 2019. A study of Coalbed Methane (CBM) reservoir boundary detections based on azimuth electromagnetic waves. Journal of Petroleum Science and Engineering 179, 432-443.


Guo, C., Xia, Y., Ma, D., Sun, X., Dai, G., Shen, J., Chen, Y., Lu, L., 2019. Geological conditions of coalbed methane accumulation in the Hancheng area, southeastern Ordos Basin, China: Implications for coalbed methane high-yield potential. Energy Exploration & Exploitation 37, 922-944.


Okolo, G.N., Everson, R.C., Neomagus, H.W.J.P., Sakurovs, R., Grigore, M., Bunt, J.R., 2019. The carbon dioxide, methane and nitrogen high-pressure sorption properties of South African bituminous coals. International Journal of Coal Geology 209, 40-53.


Zhang, J., Tang, Y., Chen, D., 2019. Prediction of methane adsorption content in continental coal-bearing shale reservoir using SLD model. Petroleum Science and Technology 37, 1839-1845.

Cosmochemistry/Planetary Geochemistry

Baines, K.H., Sromovsky, L.A., Carlson, R.W., Momary, T.W., Fry, P.M., 2019. The visual spectrum of Jupiter's Great Red Spot accurately modeled with aerosols produced by photolyzed ammonia reacting with acetylene. Icarus 330, 217-229.

Bâldea, I., 2019. Long carbon-based chains of interstellar medium can have a triplet ground state. Why is this important for astrochemistry? ACS Earth and Space Chemistry 3, 863-872.

Benna, M., Hurley, D.M., Stubbs, T.J., Mahaffy, P.R., Elphic, R.C., 2019. Lunar soil hydration constrained by exospheric water liberated by meteoroid impacts. Nature Geoscience 12, 333-338.

Bonomo, A.S., Zeng, L., Damasso, M., Leinhardt, Z.M., Justesen, A.B., Lopez, E., Lund, M.N., Malavolta, L., Silva Aguirre, V., Buchhave, L.A., Corsaro, E., Denman, T., Lopez-Morales, M., Mills, S.M., Mortier, A., Rice, K., Sozzetti, A., Vanderburg, A., Affer, L., Arentoft, T., Benbakoura, M., Bouchy, F., Christensen-Dalsgaard, J., Collier Cameron, A., Cosentino, R., Dressing, C.D., Dumusque, X., Figueira, P., Fiorenzano, A.F.M., García, R.A., Handberg, R., Harutyunyan, A., Johnson, J.A., Kjeldsen, H., Latham, D.W., Lovis, C., Lundkvist, M.S., Mathur, S., Mayor, M., Micela, G., Molinari, E., Motalebi, F., Nascimbeni, V., Nava, C., Pepe, F., Phillips, D.F., Piotto, G., Poretti, E., Sasselov, D., Ségransan, D., Udry, S., Watson, C., 2019. A giant impact as the likely origin of different twins in the Kepler-107 exoplanet system. Nature Astronomy 3, 416-423.

Brundrett, M., Yan, W., Velazquez, M.C., Rao, B., Jackson, W.A., 2019. Abiotic reduction of chlorate by Fe(II) minerals: Implications for occurrence and transformation of oxy-chlorine species on Earth and Mars. ACS Earth and Space Chemistry 3, 700-710.

Bultel, B., Viennet, J.-C., Poulet, F., Carter, J., Werner, S.C., 2019. Detection of carbonates in martian weathering profiles. Journal of Geophysical Research: Planets 124, 989-1007.

Cordier, D., Carrasco, N., 2019. The floatability of aerosols and wave damping on Titan’s seas. Nature Geoscience 12, 315-320.

Couturier-Tamburelli, I., 2019. To sink or swim in Titan’s lakes. Nature Geoscience 12, 310-311.

Cruz, F.J.A.L., Alavi, S., Mota, J.P.B., 2019. Low-temperature thermodynamic study of the metastable empty clathrate hydrates using molecular simulations. ACS Earth and Space Chemistry 3, 789-799.

Dinelli, B.M., Puertas, M.L., Fabiano, F., Adriani, A., Moriconi, M.L., Funke, B., García-Comas, M., Oliva, F., D'Aversa, E., Filacchione, G., 2019. Climatology of CH4, HCN and C2H2 in Titan's upper atmosphere from Cassini/VIMS observations. Icarus 331, 83-97.

Giuranna, M., Viscardy, S., Daerden, F., Neary, L., Etiope, G., Oehler, D., Formisano, V., Aronica, A., Wolkenberg, P., Aoki, S., Cardesín-Moinelo, A., Marín-Yaseli de la Parra, J., Merritt, D., Amoroso, M., 2019. Independent confirmation of a methane spike on Mars and a source region east of Gale Crater. Nature Geoscience 12, 326-332.

Hargitai, H.I., Gulick, V.C., Glines, N.H., 2019. Evolution of the Navua Valles region: Implications for Mars' paleoclimatic history. Icarus 330, 91-102.

Moores, J.E., Gough, R.V., Martinez, G.M., Meslin, P.-Y., Smith, C.L., Atreya, S.K., Mahaffy, P.R., Newman, C.E., Webster, C.R., 2019. Methane seasonal cycle at Gale Crater on Mars consistent with regolith adsorption and diffusion. Nature Geoscience 12, 321-325.

Olsen, P.E., Laskar, J., Kent, D.V., Kinney, S.T., Reynolds, D.J., Sha, J., Whiteside, J.H., 2019. Mapping solar system chaos with the geological orrery. Proceedings of the National Academy of Sciences 116, 10664.

ASTROBIOLOGY

Aerts, J.W., van Spanning, R.J.M., Flahaut, J., Molenaar, D., Bland, P.A., Genge, M.J., Ehrenfreund, P., Martins, Z., 2019. Microbial communities in sediments from four mildly acidic ephemeral salt lakes in the Yilgarn Craton (Australia) – terrestrial analogs to ancient Mars. Frontiers in Microbiology 10, 779. doi: 710.3389/fmicb.2019.00779.

Forgan, D.H., 2019. Exoplanet transits as the foundation of an interstellar communications network. International Journal of Astrobiology 18, 189-198.

Harnett, E.M., Johns, D., Gardner, J., Finneran, K., Davis, H., Massarano, B., 2019. An integrated approach for delivering current astrobiology research to the general public. Astrobiology 19, 696-708.

Hippke, M., 2019. Interstellar communication. I. Maximized data rate for lightweight space-probes. International Journal of Astrobiology 18, 267-279.

Ivarsson, M., Sallstedt, T., Carlsson, D.-T., 2019. Morphological biosignatures in volcanic rocks – applications for life detection on Mars. Frontiers in Earth Science 7, 91. doi: 10.3389/feart.2019.00091.


Losch, A., 2019. The need of an ethics of planetary sustainability. International Journal of Astrobiology 18, 259-266.


Michalski, J.R., Glotch, T.D., Rogers, A.D., Niles, P.B., Cuadros, J., Ashley, J.W., Johnson, S.S., 2019. The geology and astrobiology of McLaughlin Crater, Mars: An ancient lacustrine basin containing turbidites, mudstones, and serpentinites. Journal of Geophysical Research: Planets 124, 910-940.

Persson, E., Capova, K.A., Li, Y., 2019. Attitudes towards the scientific search for extraterrestrial life among Swedish high school and university students. International Journal of Astrobiology 18, 280-288.

Shahar, A., Driscoll, P., Weinberger, A., Cody, G., 2019. What makes a planet habitable? Science 364, 434-435.

Sharma, M., 2019. Precambrian biosphere: An analogue for astrobiology. Journal of the Geological Society of India 93, 622-622.

Sholes, S.F., Krissansen-Totton, J., Catling, D.C., 2019. A maximum subsurface biomass on Mars from untapped free energy: CO and H2 as potential antibiosignatures. Astrobiology 19, 655-668.

Sivaram, C., Arun, K., Kiren, O.V., 2019. Alternative standard frequencies for interstellar communication. International Journal of Astrobiology 18, 209-210.

Sivaram, C., Arun, K., Kiren, O.V., 2019. Bioenergetics and stellar luminosities. International Journal of Astrobiology 18, 211-212.

Stevenson, D.S., Large, S., 2019. Evolutionary exobiology: towards the qualitative assessment of biological potential on exoplanets. International Journal of Astrobiology 18, 204-208.

Vance, S.D., Barge, L.M., Cardoso, S.S.S., Cartwright, J.H.E., 2019. Self-assembling ice membranes on Europa: Brinicle properties, field examples, and possible energetic systems in icy ocean worlds. Astrobiology 19, 685-695.

Vidal, C., 2019. Pulsar positioning system: a quest for evidence of extraterrestrial engineering. International Journal of Astrobiology 18, 213-234.

Environmental Geochemistry

Adeleye, A.S., Ho, K.T., Zhang, M., Li, Y., Burgess, R.M., 2019. Fate and transformation of graphene oxide in estuarine and marine waters. Environmental Science & Technology 53, 5858-5867.

Cardoso-Saldaña, F.J., Kimura, Y., Stanley, P., McGaughey, G., Herndon, S.C., Roscioli, J.R., Yacovitch, T.I., Allen, D.T., 2019. Use of light alkane fingerprints in attributing emissions from oil and gas production. Environmental Science & Technology 53, 5483-5492.

Chen, W., Teng, C.-Y., Qian, C., Yu, H.-Q., 2019. Characterizing properties and environmental behaviors of dissolved organic matter using two-dimensional correlation spectroscopic analysis. Environmental Science & Technology 53, 4683-4694.

Daae, H.L., Heldal, K.K., Madsen, A.M., Olsen, R., Skaugset, N.P., Graff, P., 2019. Occupational exposure during treatment of offshore drilling waste and characterization of microbiological diversity. Science of The Total Environment 681, 533-540.

Dahl, M., Survo, S., Välitalo, P., Kabiersch, G., Alitalo, O.-S., Penttinen, O.-P., Rantalainen, A.-L., 2019. Identification of toxicants from a highly C10–C40-contaminated sediment influenced by the wood industry: Petroleum hydrocarbons or biogenic organic compounds? Environmental Toxicology and Chemistry 38, 936-946.

Han, B., Zheng, L., Lin, F., 2019. Risk assessment and source apportionment of PAHs in surface sediments from Caofeidian Long Island, China. Marine Pollution Bulletin 145, 42-46.

Jacobson, M.Z., 2019. Short-term impacts of the Aliso Canyon natural gas blowout on weather, climate, air quality, and health in California and Los Angeles. Environmental Science & Technology 53, 6081-6093.

Jafarabadi, A.R., Dashtbozorg, M., Bakhtiari, A.R., Maisano, M., Cappello, T., 2019. Geochemical imprints of occurrence, vertical distribution and sources of aliphatic hydrocarbons, aliphatic ketones, hopanes and steranes in sediment cores from ten Iranian Coral Islands, Persian Gulf. Marine Pollution Bulletin 144, 287-298.

Lan, X., Tans, P., Sweeney, C., Andrews, A., Dlugokencky, E., Schwietzke, S., Kofler, J., McKain, K., Thoning, K., Crotwell, M., Montzka, S., Miller, B.R., Biraud, S.C., 2019. Long-term measurements show little evidence for large increases in total U.S. methane emissions over the past decade. Geophysical Research Letters 46, 4991-4999.

Rodionov, A., Lehndorff, E., Stremtan, C.C., Brand, W.A., Königshoven, H.-P., Amelung, W., 2019. Spatial microanalysis of natural 13C/12C abundance in environmental samples using laser ablation-isotope ratio mass spectrometry. Analytical Chemistry 91, 6225-6232.

Wright, M.T., McMahon, P.B., Landon, M.K., Kulongoski, J.T., 2019. Groundwater quality of a public supply aquifer in proximity to oil development, Fruitvale oil field, Bakersfield, California. Applied Geochemistry 106, 82-95.

Zhu, C., Zhou, R., Zhang, Y., Chen, J., Tang, S., Li, X., Zeng, X., 2019. The detection of petroleum contaminants in soil based on multiphoton electron extraction spectroscopy. Analytical Methods 11, 2611-2616.

BIOREMEDIATION

Chaudhary, D.K., Kim, J., 2019. New insights into bioremediation strategies for oil-contaminated soil in cold environments. International Biodeterioration & Biodegradation 142, 58-72.

Huang, H., Tang, J., Niu, Z., Giesy, J.P., 2019. Interactions between electrokinetics and rhizoremediation on the remediation of crude oil-contaminated soil. Chemosphere 229, 418-425.




Wu, T., Xu, J., Liu, J., Guo, W.-H., Li, X.-B., Xia, J.-B., Xie, W.-J., Yao, Z.-G., Zhang, Y.-M., Wang, R.-Q., 2019. Characterization and initial application of endophytic Bacillus safensis strain ZY16 for improving phytoremediation of oil-contaminated saline soils. Frontiers in Microbiology 10, 991. doi: 910.3389/fmicb.2019.00991.

DEEPWATER HORIZON/MACONDO/OTHER OIL SPILLS

Altobelli, S.A., Conradi, M.S., Fukushima, E., Hodgson, J., Nedwed, T.J., Palandro, D.A., Peach, A., Sowko, N.J., Thomann, H., 2019. Helicopter-borne NMR for detection of oil under sea-ice. Marine Pollution Bulletin 144, 160-166.

Beirão, J., Baillon, L., Litt, M.A., Langlois, V.S., Purchase, C.F., 2019. Impact of crude oil and the dispersant Corexit™ EC9500A on capelin (Mallotus villosus) embryo development. Marine Environmental Research 147, 90-100.

Bullock, R.J., Perkins, R.A., Aggarwal, S., 2019. In-situ burning with chemical herders for Arctic oil spill response: Meta-analysis and review. Science of The Total Environment 675, 705-716.

Davies, E.J., Dunnebier, D.A.E., Johansen, Ø., Masutani, S., Nagamine, I., Brandvik, P.J., 2019. Shedding from chemically-treated oil droplets rising in seawater. Marine Pollution Bulletin 143, 256-263.

Fernando, H., Ju, H., Kakumanu, R., Bhopale, K.K., Croisant, S., Elferink, C., Kaphalia, B.S., Ansari, G.A.S., 2019. Distribution of petrogenic polycyclic aromatic hydrocarbons (PAHs) in seafood following Deepwater Horizon oil spill. Marine Pollution Bulletin 145, 200-207.

Han, B., Zheng, L., Li, Q., Lin, F., Ding, Y., 2019. Evaluation of the diagnostic ratios of adamantanes for identifying seriously weathered spilled oils from simulated experiment and actual oil spills. Environmental Geochemistry and Health 41, 817-828.

Huang, J., Stoyanov, S.R., Zeng, H., 2019. A comparison study on adsorption and interaction behaviors of diluted bitumen and conventional crude oil on model mineral surface. Fuel 253, 383-391.

Nelson, R.K., Gosselin, K.M., Hollander, D.J., Murawski, S.A., Gracia, A., Reddy, C.M., Radović, J.R., 2019. Exploring the complexity of two iconic crude oil spills in the Gulf of

Mexico (Ixtoc I and Deepwater Horizon) using comprehensive two-dimensional gas chromatography (GC × GC). Energy & Fuels 33, 3925-3933.


Sørensen, L., Hansen, B.H., Farkas, J., Donald, C.E., Robson, W.J., Tonkin, A., Meier, S., Rowland, S.J., 2019. Accumulation and toxicity of monoaromatic petroleum hydrocarbons in early life stages of cod and haddock. Environmental Pollution 251, 212-220.

Suneel, V., Saha, M., Rathore, C., Sequeira, J., Mohan, P.M.N., Ray, D., Veerasingam, S., Rao, V.T., Vethamony, P., 2019. Assessing the source of oil deposited in the surface sediment of Mormugao Port, Goa - A case study of MV Qing incident. Marine Pollution Bulletin 145, 88-95.

Xu, J., Cui, C., Feng, H., You, D., Wang, H., Li, B., 2019. Marine radar oil-spill monitoring through local adaptive thresholding. Environmental Forensics 20, 196-209.

MICROPLASTICS

Cerro-Gálvez, E., Sala, M.M., Marrasé, C., Gasol, J.M., Dachs, J., Vila-Costa, M., 2019. Modulation of microbial growth and enzymatic activities in the marine environment due to exposure to organic contaminants of emerging concern and hydrocarbons. Science of The Total Environment 678, 486-498.

Napper, I.E., Thompson, R.C., 2019. Environmental deterioration of biodegradable, oxo-biodegradable, compostable, and conventional plastic carrier bags in the sea, soil, and open-air over a 3-year period. Environmental Science & Technology 53, 4775-4783.


Yu, J., Wang, P., Ni, F., Cizdziel, J., Wu, D., Zhao, Q., Zhou, Y., 2019. Characterization of microplastics in environment by thermal gravimetric analysis coupled with Fourier transform infrared spectroscopy. Marine Pollution Bulletin 145, 153-160.

OIL SAND PROCESS WATERS/TAILING PONDS


Droppo, I.G., di Cenzo, P., Parrott, J., Power, J., 2019. The Alberta oil sands eroded bitumen/sediment transitional journey: Influence on sediment transport dynamics, PAH signatures and toxicological effect. Science of The Total Environment 677, 718-731.


Zhang, L., Zhang, Y., Gamal El-Din, M., 2019. Integrated mild ozonation with biofiltration can effectively enhance the removal of naphthenic acids from hydrocarbon-contaminated water. Science of The Total Environment 678, 197-206.

UNCONVENTIONALSHALE GAS-CBM RESOURCES

Barkley, Z.R., Lauvaux, T., Davis, K.J., Deng, A., Fried, A., Weibring, P., Richter, D., Walega, J.G., DiGangi, J., Ehrman, S.H., Ren, X., Dickerson, R.R., 2019. Estimating methane emissions from underground coal and natural gas production in southwestern Pennsylvania. Geophysical Research Letters 46, 4531-4540.

Caulton, D.R., Lu, J.M., Lane, H.M., Buchholz, B., Fitts, J.P., Golston, L.M., Guo, X., Li, Q., McSpiritt, J., Pan, D., Wendt, L., Bou-Zeid, E., Zondlo, M.A., 2019. Importance of superemitter natural gas well pads in the Marcellus Shale. Environmental Science & Technology 53, 4747-4754.

Evolution/Paleontology/Palynology


Chen, M., Strömberg, C.A.E., Wilson, G.P., 2019. Assembly of modern mammal community structure driven by Late Cretaceous dental evolution, rise of flowering plants, and dinosaur demise. Proceedings of the National Academy of Sciences 116, 9931-9940.

Finnegan, S., Gehling, J.G., Droser, M.L., 2019. Unusually variable paleocommunity composition in the oldest metazoan fossil assemblages. Paleobiology 45, 235-245.

Franeck, F., Liow, L.H., 2019. Dissecting the paleocontinental and paleoenvironmental dynamics of the great Ordovician biodiversification. Paleobiology 45, 221-234.


Mitchell, R.L., Strullu-Derrien, C., Kenrick, P., 2019. Biologically mediated weathering in modern cryptogamic ground covers and the early Paleozoic fossil record. Journal of the Geological Society 176, 430-439.

Wang, M., O’Connor, J.K., Xu, X., Zhou, Z., 2019. A new Jurassic scansoriopterygid and the loss of membranous wings in theropod dinosaurs. Nature 569, 256-259.

Wang, W., Wan, T., Becher, H., Kuderova, A., Leitch, I.J., Garcia, S., Leitch, A.R., Kovařík, A., 2019. Remarkable variation of ribosomal DNA organization and copy number in gnetophytes, a distinct lineage of gymnosperms. Annals of Botany 123, 767-781.

ORIGINS OF LIFE/MICROBIAL GENOMICS

Ball, R., Brindley, J., 2019. The power without the glory: Multiple roles of hydrogen peroxide in mediating the origin of life. Astrobiology 19, 675-684.

Blount, B.A., Ellis, T., 2019. Construction of an Escherichia coli genome with fewer codons sets records. Nature 569, 492-494.

Fredens, J., Wang, K., de la Torre, D., Funke, L.F.H., Robertson, W.E., Christova, Y., Chia, T., Schmied, W.H., Dunkelmann, D.L., Beránek, V., Uttamapinant, C., Llamazares, A.G., Elliott, T.S., Chin, J.W., 2019. Total synthesis of Escherichia coli with a recoded genome. Nature 569, 514-518.

Gill, S., Catchpole, R., Forterre, P., 2019. Extracellular membrane vesicles in the three domains of life and beyond. FEMS Microbiology Reviews 43, 273-303.

Greenwold, M.J., Cunningham, B.R., Lachenmyer, E.M., Pullman, J.M., Richardson, T.L., Dudycha, J.L., 2019. Diversification of light capture ability was accompanied by the evolution of phycobiliproteins in cryptophyte algae. Proceedings of the Royal Society B: Biological Sciences 286, 20190655.

Kang, C.S., Dunfield, P.F., Semrau, J.D., 2019. The origin of aerobic methanotrophy within the Proteobacteria. FEMS Microbiology Letters 366, Article fnz096.

Kim, H.-J., Kim, J., 2019. A prebiotic synthesis of canonical pyrimidine and purine ribonucleotides. Astrobiology 19, 669-674.


Li, S., Wang, X., Mu, W., Han, X., 2019. Chemical signal communication between two protoorganelles in a lipid-based artificial cell. Analytical Chemistry 91, 6859-6864.

Lin, S.-Y., Wang, Y.-C., Hsiao, C., 2019. Prebiotic iron originates the peptidyl transfer origin. Molecular Biology and Evolution 36, 999-1007.

Muchowska, K.B., Varma, S.J., Moran, J., 2019. Synthesis and breakdown of universal metabolic precursors promoted by iron. Nature 569, 104-107.

Pascal, R., 2019. A possible non-biological reaction framework for metabolic processes on early Earth. Nature Astronomy 569, 47-49.

Walker, S.I., 2019. The new physics needed to probe the origins of life. Nature Astronomy 569, 36-38.

Watson, T., 2019. The trickster microbes that are shaking up the tree of life. Nature 569, 322-324.

Zak, M., 2019. A model of emerging intelligence in Universe. International Journal of Astrobiology 18, 251-258.

HOMINID EVOLUTION

Chen, F., Welker, F., Shen, C.-C., Bailey, S.E., Bergmann, I., Davis, S., Xia, H., Wang, H., Fischer, R., Freidline, S.E., Yu, T.-L., Skinner, M.M., Stelzer, S., Dong, G., Fu, Q., Dong, G., Wang, J., Zhang, D., Hublin, J.-J., 2019. A late Middle Pleistocene Denisovan mandible from the Tibetan Plateau. Nature 569, 409-412.

Du, A., Alemseged, Z., 2019. Temporal evidence shows Australopithecus sediba is unlikely to be the ancestor of Homo. Science Advances 5, Article eaav9038.

Gibbons, A., 2019. Ancient jaw gives elusive Denisovans a face. Science 364, 418-419.

Gómez-Robles, A., 2019. Dental evolutionary rates and its implications for the Neanderthal–modern human divergence. Science Advances 5, Article eaaw1268.

Warren, M., 2019. Biggest Denisovan fossil yet spills ancient human’s secrets. Nature Astronomy 569, 16-17.

Wu, X.-J., Pei, S.-W., Cai, Y.-J., Tong, H.-W., Li, Q., Dong, Z., Sheng, J.-C., Jin, Z.-T., Ma, D.-D., Xing, S., Li, X.-L., Cheng, X., Cheng, H., de la Torre, I., Edwards, R.L., Gong, X.-C., An, Z.-S., Trinkaus, E., Liu, W., 2019. Archaic human remains from Hualongdong, China, and Middle Pleistocene human continuity and variation. Proceedings of the National Academy of Sciences 116, 9820-9824.

Fluid Inclusions

Hurai, V., Černušák, I., Randive, K., 2019. Hydrogen recovery from H2S-CH4 inclusions trapped in quartz triggered by green laser-induced photolysis of polysulphane-sulphur bonds. Applied Geochemistry 106, 75-81.

Morad, D., Nader, F.H., Morad, S., Rossi, C., Gasparrini, M., Alsuwaidi, M., Al Darmaki, F., Hellevang, H., 2019. Limited thermochemical sulfate reduction in hot, anhydritic, sour gas carbonate reservoirs: The Upper Jurassic Arab Formation, United Arab Emirates. Marine and Petroleum Geology 106, 30-41.

Ping, H., Chen, H., Zhai, P., Zhu, J., George, S.C., 2019. Petroleum charge history in the Baiyun depression and Panyu lower uplift in the Pearl River Mouth Basin, northern South China Sea: Constraints from integration of organic geochemical and fluid inclusion data. American Association of Petroleum Geologist Bulletin 103, 1401-1442.

Zhu, G., Zhang, Z., Milkov, A.V., Zhou, X., Yang, H., Han, J., 2019. Diamondoids as tracers of late gas charge in oil reservoirs: Example from the Tazhong area, Tarim Basin, China. Fuel 253, 998-1017.

General Interest

Blanco, E., Hodgson, D.J.M., Hermes, M., Besseling, R., Hunter, G.L., Chaikin, P.M., Cates, M.E., Van Damme, I., Poon, W.C.K., 2019. Conching chocolate is a prototypical transition from frictionally jammed solid to flowable suspension with maximal solid content. Proceedings of the National Academy of Sciences 116, 10303-10308.

Cafferty, B.J., Ten, A.S., Fink, M.J., Morey, S., Preston, D.J., Mrksich, M., Whitesides, G.M., 2019. Storage of information using small organic molecules. ACS Central Science 5, 911-916.

Kunene, T., Xiong, L., Rosenthal, J., 2019. Solar-powered synthesis of hydrocarbons from carbon dioxide and water. Proceedings of the National Academy of Sciences 116, 9693-9695.

Lu, A., Li, Y., Ding, H., Xu, X., Li, Y., Ren, G., Liang, J., Liu, Y., Hong, H., Chen, N., Chu, S., Liu, F., Li, Y., Wang, H., Ding, C., Wang, C., Lai, Y., Liu, J., Dick, J., Liu, K., Hochella Fr., M.F., 2019. Photoelectric conversion on Earth’s surface via widespread Fe- and Mn-mineral coatings. Proceedings of the National Academy of Sciences 116, 9741-9746.

Wismann, S.T., Engbæk, J.S., Vendelbo, S.B., Bendixen, F.B., Eriksen, W.L., Aasberg-Petersen, K., Frandsen, C., Chorkendorff, I., Mortensen, P.M., 2019. Electrified methane reforming: A compact approach to greener industrial hydrogen production. Science 364, 756-759.

Geology



Sanz-Robinson, J., Williams-Jones, A.E., 2019. Zinc solubility, speciation and deposition: A role for liquid hydrocarbons as ore fluids for Mississippi Valley Type Zn-Pb deposits. Chemical Geology 520, 60-68.

BOLIDE IMPACTS/CRATER GEOCHEMISTRY


Fernandes, V.A, Hopp, J., Schwarz, W.H., Fritz, J.P., Trieloff, M., Povenmire, H., 2019. 40Ar-39Ar step heating ages of North American tektites and of impact melt rock samples from the Chesapeake Bay impact structure. Geochimica et Cosmochimica Acta 255, 289-308.

Hydrates

Chen, B., Sun, H., Li, K., Wang, D., Yang, M., 2019. Experimental investigation of natural gas hydrate production characteristics via novel combination modes of depressurization with water flow erosion. Fuel 252, 295-303.


Guan, J., Wan, L., Liang, D., 2019. Gauging formation dynamics of structural-seepage methane hydrate reservoirs in Shenhu area of northern South China Sea: Impact of seafloor sedimentation and assessment of controlling factors. Marine and Petroleum Geology 107, 185-197.

Jung, J., Kang, H., Cao, S.C., Al-Raoush, R.I., Alshibli, K., Lee, J.Y., 2019. Effects of fine-grained particles’ migration and clogging in porous media on gas production from hydrate-bearing sediments. Geofluids 2019, Article 5061216.


Liu, P., Sun, S.Z., Hu, L., 2019. Estimation of gas hydrate saturation at the slope in the northwest of South China Sea. Petroleum Science and Technology 37, 1777-1787.

Lu, Z., Zhai, G., Zuo, Y., Wang, Q., Fan, D., Tang, S., Hu, D., Liu, H., Wang, T., Zhu, Y., Xiao, R., 2019. The geological process for gas hydrate formation in the Qilian Mountain permafrost. Petroleum Science and Technology 37, 1566-1581.

Moridis, G.J., Queiruga, A.F., Reagan, M.T., 2019. Simulation of gas production from multilayered hydrate-bearing media with fully coupled flow, thermal, chemical and geomechanical processes using TOUGH + Millstone. Part 1: Numerical modeling of hydrates. Transport in Porous Media 128, 405-430.

Ou, W., Lu, W., Ning, F., Wu, X., 2019. Measurement of methane solubility in pure water in equilibrium with hydrate by using high–pressure optical capillary cell. Marine Chemistry 212, 74-82.

Ramu, R., Sain, K., 2019. Characterization of gas hydrates reservoirs in Krishna-Godavari Basin, eastern Indian margin. Journal of the Geological Society of India 93, 539-545.

Isotope Geochemistry

Balter, V., Martin, J.E., Tacail, T., Suan, G., Renaud, S., Girard, C., 2019. Calcium stable isotopes place Devonian conodonts as first level consumers. Geochemical Perspectives Letters 10, 36–39.

Lavrieux, M., Birkholz, A., Meusburger, K., Wiesenberg, G.L.B., Gilli, A., Stamm, C., Alewell, C., 2019. Plants or bacteria? 130 years of mixed imprints in Lake Baldegg sediments

(Switzerland), as revealed by compound-specific isotope analysis (CSIA) and biomarker analysis. Biogeosciences 16, 2131-2146.

Li, Y., Yang, S., Luo, P., Xiong, S., 2019. Aridity-controlled hydrogen isotope fractionation between soil n-alkanes and precipitation in China. Organic Geochemistry 133, 53-64.

Ni, Y., Liao, F., Gao, J., Chen, J., Yao, L., Zhang, D., 2019. Hydrogen isotopes of hydrocarbon gases from different organic facies of the Zhongbai gas field, Sichuan Basin, China. Journal of Petroleum Science and Engineering 179, 776-786.

Pašava, J., Chrastný, V., Loukola-Ruskeeniemi, K., Šebek, O., 2019. Nickel isotopic variation in black shales from Bohemia, China, Canada, and Finland: a reconnaissance study. Mineralium Deposita 54, 719-742.

Tuerena, R.E., Ganeshram, R.S., Humphreys, M.P., Browning, T.J., Bouman, H., Piotrowski, A.P., 2019. Isotopic fractionation of carbon during uptake by phytoplankton across the South Atlantic subtropical convergence. Biogeosciences Discussions 2019, 1-29.

Witkowski, C.R., Agostini, S., Harvey, B.P., van der Meer, M.T.J., Sinninghe Damsté, J.S., Schouten, S., 2019. Validation of carbon isotope fractionation in algal lipids as a PCO2 proxy using a natural CO2 seep (Shikine Island, Japan). Biogeosciences Discussionjs 2019, 1-18.

CLUMPED ISOTOPES

Brasier, A.T., Dennis, P.F., Still, J., Parnell, J., Culwick, T., Brasier, M.D., Wacey, D., Bowden, S.A., Crook, S., Boyce, A.J., Muirhead, D.K., 2019. Detecting ancient life: Investigating the nature and origin of possible stromatolites and associated calcite from a one billion year old lake. Precambrian Research 328, 309-320.

Dennis, P.F., Myhill, D.J., Marca, A., Kirk, R., 2019. Clumped isotope evidence for episodic, rapid flow of fluids in a mineralized fault system in the Peak District, UK. Journal of the Geological Society 176, 447-461.

Guo, Y., Deng, W., Wei, G., Lo, L., Wang, N., 2019. Clumped isotopic signatures in land-snail shells revisited: Possible palaeoenvironmental implications. Chemical Geology 519, 83-94.

Hu, A., Shen, A., Wang, Y., Pan, L., Wang, Y., Hao, Y., Zhang, J., 2019. The geochemical characteristics and origin analysis of the botryoidal dolomite in the Upper Sinian Dengying Formation in the Sichuan Basin, China. Journal of Natural Gas Geoscience 4, 93-100.

Li, L., Fan, M., Davila, N., Jesmok, G., Mitsunaga, B., Tripati, A., Orme, D., 2019. Carbonate stable and clumped isotopic evidence for late Eocene moderate to high elevation of the east-central Tibetan Plateau and its geodynamic implications. GSA Bulletin 131, 831-844.

Piasecki, A., Bernasconi, S.M., Grauel, A.-L., Hannisdal, B., Ho, S.L., Leutert, T.J., Marchitto, T.M., Meinicke, N., Tisserand, A., Meckler, N., 2019. Application of clumped isotope thermometry to benthic foraminifera. Geochemistry, Geophysics, Geosystems 20, 2082-2090.

Zhai, J., Wang, X., Qin, B., Cui, L., Zhang, S., Ding, Z., 2019. Clumped isotopes in land snail shells over China: Towards establishing a biogenic carbonate paleothermometer. Geochimica et Cosmochimica Acta 257, 68-79.

METHODS/INSTRUMENTATION


Mathematical Geochemistry/Phase Behavior

Bagherinia, R., Assareh, M., Feyzi, F., 2019. Thermodynamic modelling of wax precipitation using PC-SAFT in a multi-solid framework. International Journal of Oil, Gas and Coal Technology 21, 229-249.

Cañas-Marín, W.A., González, D.L., Hoyos, B.A., 2019. A theoretically modified PC-SAFT equation of state for predicting asphaltene onset pressures at low temperatures. Fluid Phase Equilibria 495, 1-11.


Eghbali, S., Dehghanpour, H., 2019. An experimental and modeling study on interactions of Cold Lake bitumen with CO2, C3, and C4 at high temperatures. Energy & Fuels 33, 3957-3969.

Headen, T.F., Hoepfner, M.P., 2019. Predicting asphaltene aggregate structure from molecular dynamics simulation: Comparison to neutron total scattering data. Energy & Fuels 33, 3787-3795.

Jamali, A., Vinhal, A.P.C.M., Behnejad, H., Yan, W., Kontogeorgis, G.M., 2019. Comparison of two crossover procedures for describing thermodynamic behavior of normal alkanes from singular critical to regular classical regions. Fluid Phase Equilibria 495, 33-46.

Nascimento, F.P., Costa, G.M.N., Vieira de Melo, S.A.B., 2019. A comparative study of CPA and PC-SAFT equations of state to calculate the asphaltene onset pressure and phase envelope. Fluid Phase Equilibria 494, 74-92.

Nascimento, F.P., Souza, M.M.S., Costa, G.M.N., Vieira de Melo, S.A.B., 2019. Modeling of the asphaltene onset pressure from few experimental data: A comparative evaluation of the Hirschberg method and the cubic-plus-association equation of state. Energy & Fuels 33, 3733–3742.

Pérez-Zárate, D., Santoyo, E., Acevedo-Anicasio, A., Díaz-González, L., García-López, C., 2019. Evaluation of artificial neural networks for the prediction of deep reservoir

temperatures using the gas-phase composition of geothermal fluids. Computers & Geosciences 129, 49-68.

Zhang, T., Chen, X., Shen, H., Da, Z., 2019. Upgrading of Tsingtao vacuum residuum in supercritical water (I): A preliminary phase structure study by molecular dynamics simulations. Energy & Fuels 33, 3908-3915.


Microbiology/Extremophiles

Becker, J.W., Hogle, S.L., Rosendo, K., Chisholm, S.W., 2019. Co-culture and biogeography of Prochlorococcus and SAR11. The ISME Journal 13, 1506-1519.

Carr, S.A., Jungbluth, S.P., Eloe-Fadrosh, E.A., Stepanauskas, R., Woyke, T., Rappé, M.S., Orcutt, B.N., 2019. Carboxydotrophy potential of uncultivated Hydrothermarchaeota from the subseafloor crustal biosphere. The ISME Journal 13, 1457-1468.

Cramm, M.A., Chakraborty, A., Li, C., Ruff, S.E., Jørgensen, B.B., Hubert, C.R.J., 2019. Freezing tolerance of thermophilic bacterial endospores in marine sediments. Frontiers in Microbiology 10, 945. doi: 910.3389/fmicb.2019.00945.


Kim, Y.H., Leriche, G., Diraviyam, K., Koyanagi, T., Gao, K., Onofrei, D., Patterson, J., Guha, A., Gianneschi, N., Holland, G.P., Gilson, M.K., Mayer, M., Sept, D., Yang, J., 2019. Entropic effects enable life at extreme temperatures. Science Advances 5, Article eaaw4783.

Sedláček, I., Pantůček, R., Králová, S., Mašlaňová, I., Holochová, P., Staňková, E., Vrbovská, V., Švec, P., Busse, H.-J., 2019. Hymenobacter amundsenii sp. nov. resistant to ultraviolet radiation, isolated from regoliths in Antarctica. Systematic and Applied Microbiology 42, 284-290.

MICROBIAL ECOSYSTEMS


Belle, S., Parent, C., 2019. Reconstruction of past dynamics of methane-oxidizing bacteria in lake sediments using a quantitative PCR method: Connecting past environmental changes and microbial community. Geomicrobiology Journal 36, 570-579.

Butina, T.V., Bukin, Y.S., Krasnopeev, A.S., Belykh, O.I., Tupikin, A.E., Kabilov, M.R., Sakirko, М.V., Belikov, S.I., 2019. Estimate of the diversity of viral and bacterial assemblage in the coastal water of Lake Baikal. FEMS Microbiology Letters 366, Article fnz094.

Chen, L., Hu, B.X., Dai, H., Zhang, X., Xia, C.-A., Zhang, J., 2019. Characterizing microbial diversity and community composition of groundwater in a salt-freshwater transition zone. Science of The Total Environment 678, 574-584.


Gulliver, D., Lipus, D., Ross, D., Bibby, K., 2019. Insights into microbial community structure and function from a shallow, simulated CO2-leakage aquifer demonstrate microbial selection and adaptation. Environmental Microbiology Reports 11, 338-351.

Kirkpatrick, J.B., Walsh, E.A., D’Hondt, S., 2019. Microbial selection and survival in subseafloor sediment. Frontiers in Microbiology 10, 956. doi: 910.3389/fmicb.2019.00956.

Langenheder, S., Lindström, E.S., 2019. Factors influencing aquatic and terrestrial bacterial community assembly. Environmental Microbiology Reports 11, 306-315.

Lazar, C.S., Lehmann, R., Stoll, W., Rosenberger, J., Totsche, K.U., Küsel, K., 2019. The endolithic bacterial diversity of shallow bedrock ecosystems. Science of The Total Environment 679, 35-44.

Li, W., Morgan-Kiss, R.M., 2019. Influence of environmental drivers and potential interactions on the distribution of microbial communities from three permanently stratified Antarctic lakes. Frontiers in Microbiology 10, 1067. doi: 1010.3389/fmicb.2019.01067.

Mijnendonckx, K., Miroslav, H., Wang, L., Jacops, E., Provoost, A., Mysara, M., Wouters, K., De Craen, M., Leys, N., 2019. An active microbial community in Boom Clay pore water collected from piezometers impedes validating predictive modelling of ongoing geochemical processes. Applied Geochemistry 106, 149-160.

Mitzscherling, J., Horn, F., Winterfeld, M., Mahler, L., Kallmeyer, J., Overduin, P.P., Schirrmeister, L., Winkel, M., Grigoriev, M.N., Wagner, D., Liebner, S., 2019. Microbial community composition and abundance after millennia of submarine permafrost warming. Biogeosciences Discussions 2019, 1-29.

Qin, H., Wang, S., Feng, K., He, Z., Virta, M.P.J., Hou, W., Dong, H., Deng, Y., 2019. Unraveling the diversity of sedimentary sulfate-reducing prokaryotes (SRP) across Tibetan saline lakes using epicPCR. Microbiome 7, 71.

Reboul, G., Moreira, D., Bertolino, P., Hillebrand-Voiculescu, A.M., López-García, P., 2019. Microbial eukaryotes in the suboxic chemosynthetic ecosystem of Movile Cave, Romania. Environmental Microbiology Reports 11, 464-473.

Sánchez-Sánchez, J., Cerca, M., Alcántara-Hernández, R.J., Lozano-Flores, C., Carreón-Freyre, D., Levresse, G., Vega, M., Varela-Echavarría, A., Aranda-Gómez, J.J., 2019.

Extant microbial communities in the partially desiccated Rincon de Parangueo maar crater lake in Mexico. FEMS Microbiology Ecology 95, Article fiz051.


Stal, L.J., Bolhuis, H., Cretoiu, M.S., 2019. Phototrophic marine benthic microbiomes: the ecophysiology of these biological entities. Environmental Microbiology 21, 1529-1551.

Theiling, B.P., Coleman, M., 2019. The relationship of diagenesis with a complex microbial ecosystem in the phosphatic interval of the Miocene Monterey Formation: evidence from stable isotopes and mineralogy. Marine Geology 413, 112-128.

Yang, L., Tang, L., Li, H., Wang, L., Zhang, Y., 2019. Unique microbial communities inhabiting underground seawater in an intertidal area utilized for industrialized aquaculture, as compared with the coastal water. Geomicrobiology Journal 36, 483-491.

Zakharyuk, A.G., Ryzhmanova, Y.V., Avtukh, A.N., Shcherbakova, V.A., 2019. Iron-reducing microbial communities of the Lake Baikal low-temperature bottom sediments. Microbiology 88, 156-163.

Zha, J., Zhuang, Q., 2019. Microbial dormancy and its impacts on Arctic terrestrial ecosystem carbon budget. Biogeosciences Discussions 2019, 1-44.



PETROLEUM DEGRADERS


Barbato, M., Mapelli, F., Crotti, E., Daffonchio, D., Borin, S., 2019. Cultivable hydrocarbon degrading bacteria have low phylogenetic diversity but highly versatile functional potential. International Biodeterioration & Biodegradation 142, 43-51.

Godini, K., Samarghandi, M.R., Tahmasebi, H., Zarei, O., Karimitabar, Z., Yarahmadi, Z., Arabestani, M.R., 2019. Biochemical and molecular characterization of novel PAH-degrading bacteria isolated from polluted soil and sludge. Petroleum Science and Technology 37, 1763-1769.

Liu, J., Zheng, Y., Lin, H., Wang, X., Li, M., Liu, Y., Yu, M., Zhao, M., Pedentchouk, N., Lea-Smith, D.J., Todd, J.D., Magill, C.R., Zhang, W.-J., Zhou, S., Song, D., Zhong, H.,

Xin, Y., Yu, M., Tian, J., Zhang, X.-H., 2019. Proliferation of hydrocarbon-degrading microbes at the bottom of the Mariana Trench. Microbiome 7, Article 47.


Oso, S., Walters, M., Schlechter, R.O., Remus-Emsermann, M.N.P., 2019. Utilisation of hydrocarbons and production of surfactants by bacteria isolated from plant leaf surfaces. FEMS Microbiology Letters 366, Article fnz061.

van de Kamp, J., Hook, S.E., Williams, A., Tanner, J.E., Bodrossy, L., 2019. Baseline characterization of aerobic hydrocarbon degrading microbial communities in deep-sea sediments of the Great Australian Bight, Australia. Environmental Microbiology 21, 1782-1797.

Oil & Gas Exploration

Guo, Q., Wang, S., Chen, X., 2019. Assessment on tight oil resources in major basins in China. Journal of Asian Earth Sciences 178, 52-63.

Guo, Q., Wu, N., Yan, W., Chen, N., 2019. An assessment method for deep gas resources. Acta Petrolei Sinica 40, 383-394.

Menotti, T., Scheirer, A.H., Meisling, K., Graham, S.A., 2019. Integrating strike-slip tectonism with three-dimensional basin and petroleum system analysis of the Salinas Basin, California. American Association of Petroleum Geologist Bulletin 103, 1443-1472.

Neumaier, M., Littke, R., Back, S., Kukla, P., Schnabel, M., Reichert, C., 2019. Hydrocarbon charge assessment of frontier basins – a case study of the oceanic crust of the Moroccan Atlantic margin. Petroleum Geoscience, 151-168.


Wang, W., Pang, X., Chen, Z., Chen, D., Yu, R., Luo, B., Zheng, T., Li, H., 2019. Statistical evaluation and calibration of model predictions of the oil and gas field distributions in superimposed basins: A case study of the Cambrian Longwangmiao Formation in the Sichuan Basin, China. Marine and Petroleum Geology 106, 42-61.

Wen, Z., Jiang, S., Song, C., Wang, Z., He, Z., 2019. Basin evolution, configuration styles, and hydrocarbon accumulation of the South Atlantic conjugate margins. Energy Exploration & Exploitation 37, 992-1008.

Zhang, G., Qu, H., Chen, G., Zhao, C., Zhang, F., Yang, H., Zhao, Z., Ma, M., 2019. Giant discoveries of oil and gas fields in global deepwaters in the past 40 years and the prospect of exploration. Journal of Natural Gas Geoscience 4, 1-28.

Oil & Gas Generation/Expulsion

Burklé-Vitzthum, V., Leguizamon Guerra, N.C., Lorgeoux, C., Faure-Catteloin, D., Bounaceur, R., Michels, R., 2019. Influence of H2S on the thermal cracking of alkylbenzenes at high pressure (70 MPa) and moderate temperature (583–623 K). Journal of Analytical and Applied Pyrolysis 140, 423-433.

Du, P., Cai, J., Liu, Q., Wang, J., 2019. The role transformation of soluble organic matter in the process of hydrocarbon generation in mud source rock. Petroleum Science and Technology 37, 1800-1807.


Huang, W., Zeng, L., Pan, C., Xiao, Z., Zhang, H., Huang, Z., Zhao, Q., Yu, S., Xu, H., Chen, C., Liu, D., Liu, J., 2019. Petroleum generation potentials and kinetics of coaly source rocks in the Kuqa Depression of Tarim Basin, northwest China. Organic Geochemistry 133, 32-52.

Liu, J., Liu, K., Liu, C., 2019. Quantitative evaluation of gas generation from the Upper Paleozoic coal, mudstone and limestone source rocks in the Ordos Basin, China. Journal of Asian Earth Sciences 178, 224-241.

Lu, S., Li, J., Xue, H., Chen, F., Xu, Q., Wang, M., Li, W., Pang, X., 2019. Pyrolytic gaseous hydrocarbon generation and the kinetics of carbon isotope fractionation in representative model compounds with different chemical structures. Geochemistry, Geophysics, Geosystems 20, 1773-1793.

Sevast’yanov, V.S., Karpov, G.A., Bychkov, A.Y., Kuznetsova, O.V., Fedulov, V.S., 2019. Effect of hydrous pyrolysis on the distribution of carbon and hydrogen isotopes between fractions of organic matter. The nature of oil seeps in the Uzon Caldera, Kamchatka, Russia. Geochemistry International 57, 233-242.

Sharov, G.N., Khadzhiev, S.N., 2019. On the inexhaustibility of oil reserves (Belozerov–Sharov–Minin Hypothesis). Petroleum Chemistry 59, 129-134.

Sun, Y., Liu, Z., Li, Q., Deng, S., Guo, W., 2019. Controlling groundwater infiltration by gas flooding for oil shale in situ pyrolysis exploitation. Journal of Petroleum Science and Engineering 179, 444-454.

Zhao, W., Wang, X., Hu, S., Zhang, S., Wang, H., Guan, S., Ye, Y., Ren, R., Wang, T., 2019. Hydrocarbon generation characteristics and exploration prospects of Proterozoic source rocks in China. Science China Earth Sciences 62, 909-934.

Oil & Gas Geochemistry

Ahmed, O.E., Eldesoky, A.M., El Nady, M.M., 2019. Oil hydrocarbon fingerprints of the different marine organisms in some Egyptian Gulf of Suez waters. Petroleum Science and Technology 37, 1722-1730.

Atwah, I., Sweet, S., Pantano, J., Knap, A., 2019. Light hydrocarbon geochemistry: Insight into Mississippian crude oil sources from the Anadarko Basin, Oklahoma, USA. Geofluids 2019, Article 2795017.

Cai, C., Tang, Y., Li, K., Jiang, K., Jiang, C., Xiao, Q., 2019. Relative reactivity of saturated hydrocarbons during thermochemical sulfate reduction. Fuel 253, 106-113.

Chen, C., Wang, Y., Beagle, J.R., Liao, L., Shi, S., Deng, R., 2019. Reconstruction of the evolution of deep fluids in light oil reservoirs in the Central Tarim Basin by using PVT simulation and basin modeling. Marine and Petroleum Geology 107, 116-126.

Fu, J., Zhang, Z., Chen, C., Wang, T.G., Li, M., Ali, S., Lu, X., Dai, J., 2019. Geochemistry and origins of petroleum in the Neogene reservoirs of the Baiyun Sag, Pearl River Mouth Basin. Marine and Petroleum Geology 107, 127-141.

He, L., Chen, J., Liu, K., Zhu, X., Zhang, C., Li, W., Luo, G., Wang, Y., 2019. Geochemical characteristics and sources of natural gas in the northern Xihu Sag Natural Gas Industry 39, 53-62.

Kamari, A., Mohammadi, A.H., Ramjugernath, D., 2019. Characterization of C7+ fraction properties of crude oils and gas-condensates using data driven models. Petroleum Science and Technology 37, 1516-1522.

Li, P., Zou, H., Hao, F., Yu, X., 2019. Sulfate sources of thermal sulfate reduction (TSR) in the Permian Changxing and Triassic Feixianguan formations, northeastern Sichuan Basin, China. Geofluids 2019, Article 5898901.

Liu, C., Liu, P., McGovern, G.P., Horita, J., 2019. Molecular and intramolecular isotope geochemistry of natural gases from the Woodford Shale, Arkoma Basin, Oklahoma. Geochimica et Cosmochimica Acta 255, 188-204.

Lu, J., Lin, R., Liu, C., Li, Y., Xiao, Z., He, Q., 2019. Genesis and origin of natural gas in the Beidagang structural belt of Dagang oilfield. Petroleum Science and Technology 37, 1501-1508.

Ma, X., Li, M., Pang, X., Wei, X., Qian, M., Tao, G., Liu, P., Jiang, Q., Li, Z., Zhao, Y., Wu, S., 2019. Paradox in bulk and molecular geochemical data and implications for hydrocarbon migration in the inter-salt lacustrine shale oil reservoir, Qianjiang Formation, Jianghan Basin, central China. International Journal of Coal Geology 209, 72-88.




Scarlett, A.G., Holman, A.I., Georgiev, S.V., Stein, H.J., Summons, R.E., Grice, K., 2019. Multi-spectroscopic and elemental characterization of southern Australian asphaltites. Organic Geochemistry 133, 77-91.


Smirnov, M.B., Vanyukova, N.A., 2019. Distribution patterns of the main structural group parameters of crude oils from the Lena–Tunguska oil-and-gas basin by 1H NMR data. Petroleum Chemistry 59, 135-142.

Zhang, J., Cao, J., Wang, Y., Hu, G., Zhou, N., Shi, T., 2019. Origin of giant vein-type bitumen deposits in the northwestern Junggar Basin, NW China: Implications for fault-controlled hydrocarbon accumulation. Journal of Asian Earth Sciences 179, 287-299.


Zhang, Z., Zhang, Y., Zhu, G., Han, J., Chi, L., 2019. Variations of diamondoids distributions in petroleum fluids during migration induced phase fractionation: A case study from the Tazhong area, NW China. Journal of Petroleum Science and Engineering 179, 1012-1022.


Paleoclimatology/Paleoceanography

Ahlberg, P., Lundberg, F., Erlström, M., Calner, M., Lindskog, A., Dahlqvist, P., Joachimski, M.M., 2019. Integrated Cambrian biostratigraphy and carbon isotope chemostratigraphy of the Grönhögen-2015 drill core, Öland, Sweden. Geological Magazine 156, 935-949.

Alberti, M., Arabas, A., Fürsich, F.T., Andersen, N., Ziółkowski, P., 2019. The Middle to Upper Jurassic stable isotope record of Madagascar: Linking temperature changes with plate tectonics during the break-up of Gondwana. Gondwana Research 73, 1-15.

Barnet, J.S.K., Littler, K., Westerhold, T., Kroon, D., Leng, M.J., Bailey, I., Röhl, U., Zachos, J.C., 2019. A high-fidelity benthic stable isotope record of Late Cretaceous–Early Eocene climate change and carbon-cycling. Paleoceanography and Paleoclimatology 34, 672-691.

Caballero-Gill, R.P., Herbert, T.D., Dowsett, H.J., 2019. 100-kyr paced climate change in the Pliocene warm period, southwest Pacific. Paleoceanography and Paleoclimatology 34, 524-545.

Dauner, A.L.L., Mollenhauer, G., Bícego, M.C., de Souza, M.M., Nagai, R.H., Figueira, R.C.L., de Mahiques, M.M., Sousa, S.H.d.M.e., Martins, C.C., 2019. Multi-proxy reconstruction of sea surface and subsurface temperatures in the western South Atlantic over the last ∼75 kyr. Quaternary Science Reviews 215, 22-34.

Frieling, J., Peterse, F., Lunt, D.J., Bohaty, S.M., Sinninghe Damsté, J.S., Reichart, G.J., Sluijs, A., 2019. Widespread warming before and elevated barium burial during the Paleocene-

Eocene Thermal Maximum: Evidence for methane hydrate release? Paleoceanography and Paleoclimatology 34, 546-566.

Galeotti, S., Sprovieri, M., Rio, D., Moretti, M., Francescone, F., Sabatino, N., Fornaciari, E., Giusberti, L., Lanci, L., 2019. Stratigraphy of early to middle Eocene hyperthermals from Possagno (Southern Alps, Italy) and comparison with global carbon isotope records. Palaeogeography, Palaeoclimatology, Palaeoecology 527, 39-52.

Gangl, S.K., Moy, C.M., Stirling, C.H., Jenkyns, H.C., Crampton, J.S., Clarkson, M.O., Ohneiser, C., Porcelli, D., 2019. High-resolution records of Oceanic Anoxic Event 2: Insights into the timing, duration and extent of environmental perturbations from the palaeo-South Pacific Ocean. Earth and Planetary Science Letters 518, 172-182.

Hammarlund, E.U., Loydell, D.K., Nielsen, A.T., Schovsbo, N.H., 2019. Early Silurian δ13Corg excursions in the foreland basin of Baltica, both familiar and surprising. Palaeogeography, Palaeoclimatology, Palaeoecology 526, 126-135.


Hülse, D., Arndt, S., Ridgwell, A., 2019. Mitigation of extreme ocean anoxic event conditions by organic matter sulfurization. Paleoceanography and Paleoclimatology 34, 476-489.


Knutz, P.C., Newton, A.M.W., Hopper, J.R., Huuse, M., Gregersen, U., Sheldon, E., Dybkjær, K., 2019. Eleven phases of Greenland Ice Sheet shelf-edge advance over the past 2.7 million years. Nature Geoscience 12, 361-368.

Mackey, J.E., Stewart, B.W., 2019. Evidence of SPICE-related anoxia on the Laurentian passive margin: Paired δ13C and trace element chemostratigraphy of the upper Conasauga Group, Central Appalachian Basin. Palaeogeography, Palaeoclimatology, Palaeoecology 528, 160-174.

Mahanipour, A., Mutterlose, J., Eftekhari, M., 2019. Calcareous nannofossils of the Barremian – Aptian interval from the southeastern Tethys (Zagros Basin, West Iran) and their paleoceanographic implications: A record of Oceanic Anoxic Event 1a. Marine Micropaleontology 149, 64-74.

Manda, Š., Štorch, P., Frýda, J., Slavík, L., Tasáryová, Z., 2019. The mid-Homerian (Silurian) biotic crisis in offshore settings of the Prague Synform, Czech Republic: Integration of the graptolite fossil record with conodonts, shelly fauna and carbon isotope data. Palaeogeography, Palaeoclimatology, Palaeoecology 528, 14-34.

Nielsen, S.B., Jochum, M., Pedro, J.B., Eden, C., Nuterman, R., 2019. Two-timescale carbon cycle response to an AMOC collapse. Paleoceanography and Paleoclimatology 34, 511-523.

Ning, D., Zhang, E., Shulmeister, J., Chang, J., Sun, W., Ni, Z., 2019. Holocene mean annual air temperature (MAAT) reconstruction based on branched glycerol dialkyl glycerol tetraethers from Lake Ximenglongtan, southwestern China. Organic Geochemistry 133, 65-76.

O'Connor, L.K., Robinson, S.A., Naafs, B.D.A., Jenkyns, H.C., Henson, S., Clarke, M., Pancost, R.D., 2019. Late Cretaceous temperature evolution of the southern high latitudes: A TEX86 perspective. Paleoceanography and Paleoclimatology 34, 436-454.

Pujalte, V., Monechi, S., Ortíz, S., Orue-Etxebarria, X., Rodríguez-Tovar, F., Schmitz, B., 2019. Microcodium-rich turbidites in hemipelagic sediments during the Paleocene–Eocene Thermal Maximum: Evidence for extreme precipitation events in a Mediterranean climate (Río Gor section, southern Spain). Global and Planetary Change 178, 153-167.

Scholz, F., Beil, S., Flögel, S., Lehmann, M.F., Holbourn, A., Wallmann, K., Kuhnt, W., 2019. Oxygen minimum zone-type biogeochemical cycling in the Cenomanian-Turonian Proto-North Atlantic across Oceanic Anoxic Event 2. Earth and Planetary Science Letters 517, 50-60.

Toggweiler, J.R., Druffel, E.R.M., Key, R.M., Galbraith, E.D., 2019. Upwelling in the ocean basins north of the ACC: 1. On the upwelling exposed by the surface distribution of Δ14C. Journal of Geophysical Research: Oceans 124, 2591-2608.

Valle, B., Dal' Bó, P.F., Mendes, M., Favoreto, J., Rigueti, A.L., Borghi, L., de Oliveira Mendonça, J., Silva, R., 2019. The expression of the Oceanic Anoxic Event 2 (OAE2) in the northeast of Brazil (Sergipe-Alagoas Basin). Palaeogeography, Palaeoclimatology, Palaeoecology 529, 12-23.

Voosen, P., 2019. Project traces 500 million years of roller-coaster climate. Science 364, 716-717.

Zheng, F., Chen, Y., Xie, W., Chen, S., Liu, H., Phelps, T.J., Zhang, C., 2019. Diverse biological sources of core and intact polar isoprenoid GDGTs in terrace soils from southwest of China: Implications for their use as environmental proxies. Chemical Geology 522, 108-120.

EXTINCTION EVENTS

Atkinson, J.W., Wignall, P.B., 2019. How quick was marine recovery after the end-Triassic mass extinction and what role did anoxia play? Palaeogeography, Palaeoclimatology, Palaeoecology 528, 99-119.

Borruel-Abadía, V., Barrenechea, J.F., Galán-Abellán, A.B., De la Horra, R., López-Gómez, J., Ronchi, A., Luque, F.J., Alonso-Azcárate, J., Marzo, M., 2019. Could acidity be the reason behind the Early Triassic biotic crisis on land? Chemical Geology 515, 77-86.

Cassel, M.C., Lavina, E.L.C., Cagliari, J., Rodrigues, R., Pereira, E., 2019. Anoxia and salinity changes: a new Permian catastrophe record. Climate of the Past Discussions 2019, 1-20.

Kwon, H., Kim, M.G., Lee, Y.I., 2019. Mercury evidence from the Sino-Korean block for Emeishan volcanism during the Capitanian mass extinction. Geological Magazine 156, 1105-1110.

Sun, Y.D., Zulla, M.J., Joachimski, M.M., Bond, D.P.G., Wignall, P.B., Zhang, Z.T., Zhang, M.H., 2019. Ammonium ocean following the end-Permian mass extinction. Earth and Planetary Science Letters 518, 211-222.

Yang, S., Hu, W., Wang, X., Jiang, B., Yao, S., Sun, F., Huang, Z., Zhu, F., 2019. Duration, evolution, and implications of volcanic activity across the Ordovician–Silurian transition in the Lower Yangtze region, South China. Earth and Planetary Science Letters 518, 13-25.

Zhang, B., Yao, S., Wignall, P.B., Hu, W., Liu, B., Ren, Y., 2019. New timing and geochemical constraints on the Capitanian (Middle Permian) extinction and environmental changes in deep-water settings: evidence from the Lower Yangtze region of South China. Journal of the Geological Society 176, 588-608.

Precambrian Geochemistry


Hao, J., Sverjensky, D.A., Hazen, R.M., 2019. Redox states of Archean surficial environments: The importance of H2,g instead of O2,g for weathering reactions. Chemical Geology 521, 49-58.

Ranjan, S., Todd, Z.R., Rimmer, P.B., Sasselov, D.D., Babbin, A.R., 2019. Nitrogen oxide concentrations in natural waters on early Earth. Geochemistry, Geophysics, Geosystems 20, 2021-2039.

Thoby, M., Konhauser, K.O., Fralick, P.W., Altermann, W., Visscher, P.T., Lalonde, S.V., 2019. Global importance of oxic molybdenum sinks prior to 2.6 Ga revealed by the Mo isotope composition of Precambrian carbonates. Geology 47, 559-562.

Zhang, Y., Pufahl, P.K., Du, Y., Chen, G., Liu, J., Chen, Q., Wang, Z., Yu, W., 2019. Economic phosphorite from the Ediacaran Doushantuo Formation, South China, and the Neoproterozoic-Cambrian Phosphogenic Event. Sedimentary Geology 388, 1-19.

ORGANICS/MICROFOSSILS/MICROBIAL EVOLUTION

Anderson, L.D., Bebout, G.E., Izawa, M.R.M., Bridge, N.J., Banerjee, N.R., 2019. Chemical alteration and preservation of sedimentary/organic nitrogen isotope signatures in a 2.7 Ga seafloor volcanic sequence. International Journal of Astrobiology 18, 235-250.


Schobben, M., van de Schootbrugge, B., 2019. Increased stability in carbon isotope records reflects emerging complexity of the biosphere. Frontiers in Earth Science 7, 87. doi: 10.3389/feart.2019.00087.



PALEOCLIMATOLOGY/PALEOCEANOGRAPHY

Fakhraee, M., Hancisse, O., Canfield, D.E., Crowe, S.A., Katsev, S., 2019. Proterozoic seawater sulfate scarcity and the evolution of ocean–atmosphere chemistry. Nature Geoscience 12, 375-380.

Khelen, A.C., Manikyamba, C., Subramanyam, K.S.V., Santosh, M., Ganguly, S., Kalpana, M.S., Subba Rao, D.V., 2019. Archean seawater composition and depositional environment – Geochemical and isotopic signatures from the stromatolitic carbonates of Dharwar Craton, India. Precambrian Research 330, 35-57.

Lantink, M.L., Davies, J.H.F.L., Mason, P.R.D., Schaltegger, U., Hilgen, F.J., 2019. Climate control on banded iron formations linked to orbital eccentricity. Nature Geoscience 12, 369-374.

Spencer, C.J., Partin, C.A., Kirkland, C.L., Raub, T.D., Liebmann, J., Stern, R.A., 2019. Paleoproterozoic increase in zircon δ18O driven by rapid emergence of continental crust. Geochimica et Cosmochimica Acta 257, 16-25.

Stolper, D.A., Bucholz, C.E., 2019. Neoproterozoic to early Phanerozoic rise in island arc redox state due to deep ocean oxygenation and increased marine sulfate levels. Proceedings of the National Academy of Sciences 116, 8746-8755.

Zou, Y., Liu, D., Zhao, F., Kuang, H., Sun, Y., Cheng, J., 2019. Chemostratigraphy of the Mesoproterozoic Shennongjia Group, Yangtze Craton (South China): Implications for oxidized shallow seawaters. Journal of Asian Earth Sciences 179, 399-415.

CRUSTAL EVOLUTION

Greber, N.D., Dauphas, N., 2019. The chemistry of fine-grained terrigenous sediments reveals a chemically evolved Paleoarchean emerged crust. Geochimica et Cosmochimica Acta 255, 247-264.

Jain, C., Rozel, A.B., Tackley, P.J., Sanan, P., Gerya, T.V., 2019. Growing primordial continental crust self-consistently in global mantle convection models. Gondwana Research 73, 96-122.

Piccolo, A., Palin, R.M., Kaus, B.J.P., White, R.W., 2019. Generation of Earth's early continents from a relatively cool Archean mantle. Geochemistry, Geophysics, Geosystems 20, 1679-1697.

Production/Engineering Geochemistry


Al-Salem, S.M., 2019. Thermal pyrolysis of high density polyethylene (HDPE) in a novel fixed bed reactor system for the production of high value gasoline range hydrocarbons (HC). Process Safety and Environmental Protection 127, 171-179.


Fomitšov, M., 2019. Low-temperature supercritical conversion of kukersite oil shale. Oil Shale 3, 171-178.

Pérez-Zárate, D., Santoyo, E., Acevedo-Anicasio, A., Díaz-González, L., García-López, C., 2019. Evaluation of artificial neural networks for the prediction of deep reservoir temperatures using the gas-phase composition of geothermal fluids. Computers & Geosciences 129, 49-68.

Rodríguez, E., Elordi, G., Valecillos, J., Izaddoust, S., Bilbao, J., Arandes, J.M., Castaño, P., 2019. Coke deposition and product distribution in the co-cracking of waste polyolefin derived streams and vacuum gas oil under FCC unit conditions. Fuel Processing Technology 192, 130-139.

ASPHALTENES

Abutaqiya, M.I.L., Sisco, C.J., Wang, J., Vargas, F.M., 2019. Systematic investigation of asphaltene deposition in the wellbore and near-wellbore region of a deepwater oil reservoir under gas injection. Part 1: Thermodynamic modeling of the phase behavior of polydisperse asphaltenes. Energy & Fuels 33, 3632-3644.

Alimohammadi, S., Zendehboudi, S., James, L., 2019. A comprehensive review of asphaltene deposition in petroleum reservoirs: Theory, challenges, and tips. Fuel 252, 753-791.

Babu, N.R., Lin, P.-H., Abutaqiya, M.I.L., Sisco, C.J., Wang, J., Vargas, F.M., 2019. Systematic investigation of asphaltene deposition in the wellbore and near-wellbore region of a deepwater oil reservoir under gas injection. Part 2: Computational fluid dynamics modeling of asphaltene deposition. Energy & Fuels 33, 3645-3661.


Duran, J.A., Casas, Y.A., Xiang, L., Zhang, L., Zeng, H., Yarranton, H.W., 2019. Nature of asphaltene aggregates. Energy & Fuels 33, 3694-3710.

Gafurov, M., Mamin, G., Gracheva, I., Murzakhanov, F., Ganeeva, Y., Yusupova, T., Orlinskii, S., 2019. High-Field (3.4 T) ENDOR investigation of asphaltenes in native oil and vanadyl complexes by asphaltene adsorption on alumina surface. Geofluids 2019, Article 381287.


Ismail, M., Yang, Y., Chaisoontornyotin, W., Ovalles, C., Rogel, E., Moir, M.E., Hoepfner, M.P., 2019. Effect of chemical inhibitors on asphaltene precipitation and morphology using ultra-small-angle X-ray scattering. Energy & Fuels 33, 3681-3693.

Krueckert, K.K., Seibold, P., 2019. Enhanced evaluation of asphaltene-related oil properties to facilitate production in a complex offshore environment. Energy & Fuels 33, 3711-3722.

Liu, D., Li, C., Yang, F., Sun, G., You, J., Cui, K., 2019. Synergetic effect of resins and asphaltenes on water/oil interfacial properties and emulsion stability. Fuel 252, 581-588.



Qiao, J., Cheng, S., Song, W., Jian, C., Wang, W., Zhang, D., Xu, Y., 2019. Probing the effect of NaCl concentrations on a model asphaltene adsorption onto water droplets of different sizes. Energy & Fuels 33, 3881-3890.


Santos, D.C., Filipakis, S.D., Lima, E.R.A., Paredes, M.L.L., 2019. Solubility parameter of oils by several models and experimental oil compatibility data: implications for asphaltene stability. Petroleum Science and Technology 37, 1596-1602.


Shetty, P.P., Zhang, R., Haire, B.T., Smith, C.S., Kenny, L.M., Wu, T., Subramani, V., Morrison, J.J., Quayle, P., Yeates, S., Braun, P.V., Krogstad, J.A., 2019. Effect of surface chemistry and roughness on the high-temperature deposition of a model asphaltene. Energy & Fuels 33, 4104-4114.

Tavakkoli, M., Sung, C.-A., Kuang, J., Chen, A., Hu, J., Vargas, F.M., 2019. Effect of carbon steel corrosion on asphaltene deposition. Energy & Fuels 33, 3808-3815.

Yonebayashi, H., Watanabe, T., Miyagawa, Y., 2019. Re-equilibrium of asphaltenes by repressurizing after precipitation in natural depletion and CO2 enhanced oil recovery schemes. Energy & Fuels 33, 3662-3672.

INTERFACES/EOR

Agi, A., Junin, R., Shirazi, R., Afeez, G., Yekeen, N., 2019. Comparative study of ultrasound assisted water and surfactant flooding. Journal of King Saud University - Engineering Sciences 31, 296-303.

Al-Khafaji, A., Wilson, M., Neville, A., Wen, D., 2019. Pore-scale displacement efficiency during different salinity water flooding in hydrophilic and hydrophobic microstructures. Energy & Fuels 33, 3859-3870.


Al Maskari, N.S., Sari, A., Saeedi, A., Xie, Q., 2019. Influence of surface roughness on the contact angle due to calcite dissolution in an oil–brine–calcite system: A nanoscale analysis using atomic force microscopy and geochemical modeling. Energy & Fuels 33, 4219-4224.

Aldousary, S., Kovscek, A.R., 2019. The diffusion of water through oil contributes to spontaneous emulsification during low salinity waterflooding. Journal of Petroleum Science and Engineering 179, 606-614.

Alekseyev, V.A., 2019. Nanoparticles and nanofluids in water–rock interactions. Geochemistry International 57, 357-368.


Cañas-Jaimes, D.-L., Cabanzo, R., Mejía-Ospino, E., 2019. Comparison of interfacial tension reduction in a toluene/water system by Colombian crude oil and its interfacially active components. Energy & Fuels 33, 3753-3763.


Fahandezhsaadi, M., Amooie, M.A., Hemmati-Sarapardeh, A., Ayatollahi, S., Schaffie, M., Ranjbar, M., 2019. Laboratory evaluation of nitrogen injection for enhanced oil recovery: Effects of pressure and induced fractures. Fuel 253, 607-614.

Hassan, S.A., Abdalla, B.K., Mustafa, M.A., 2019. Addition of silica nano-particles for the enhancement of crude oil demulsification process. Petroleum Science and Technology 37, 1603-1611.




Li, P., Yi, L., Liu, X., Hu, G., Lu, J., Zhou, D., Hovorka, S., Liang, X., 2019. Screening and simulation of offshore CO2-EOR and storage: A case study for the HZ21-1 oilfield in the Pearl River Mouth Basin, Northern South China Sea. International Journal of Greenhouse Gas Control 86, 66-81.




Liu, R., Gou, R., Pu, W.-f., Ren, H., Du, D.-j., Chen, P., Mei, Z.-l., 2019. Visual laminations combined with nuclear magnetic resonance to study the micro-unrecovered oil distribution and displacement behavior of chemical flooding in a complex conglomerate. Energy & Fuels 33, 4041-4052.

Rezk, M.G., Foroozesh, J., 2019. Effect of CO2 mass transfer on rate of oil properties changes: Application to CO2-EOR projects. Journal of Petroleum Science and Engineering 180, 298-309.

Romero Yanes, J.F., Feitosa, F.X., do Carmo, F.R., de Sant’Ana, H.B., 2019. Addition of non-endogenous paraffins in Brazilian crude oils and their effects on emulsion stability and interfacial properties. Energy & Fuels 33, 3673-3680.

Sun, R., Pu, H., Yu, W., Miao, J., Zhao, J.X., 2019. Simulation-based enhanced oil recovery predictions from wettability alteration in the Middle Bakken tight reservoir with hydraulic fractures. Fuel 253, 229-237.

Takeya, M., Shimokawara, M., Elakneswaran, Y., Okano, H., Nawa, T., 2019. Effect of acid number on the electrokinetic properties of crude oil during low-salinity waterflooding. Energy & Fuels 33, 4211-4218.

Wang, S., Chen, C., Li, K., Shiau, B., Harwell, J.H., 2019. In situ CO2 enhanced oil recovery: Parameters affecting reaction kinetics and recovery performance. Energy & Fuels 33, 3844-3854.

Wang, T., Xiu, J., Huang, L., Cui, Q., Ma, Y., Miao, J., Yu, L., 2019. A mathematical model for microbial enhanced oil recovery considering reservoir environment and microbial factor. Acta Petrolei Sinica 40, 448-456.




HEAVY OIL PRODUCTION


Elahi, S.M., Scott, C.E., Chen, Z., Pereira-Almao, P., 2019. In-situ upgrading and enhanced recovery of heavy oil from carbonate reservoirs using nano-catalysts: Upgrading reactions analysis. Fuel 252, 262-271.

Ramcharan, T., Hosein, R., 2019. Radio Frequency Heating combined with Solvent Extraction- A method for oil recovery from surface oil sands. Journal of Petroleum Science and Engineering 179, 328-336.

Saha, R., Uppaluri, R.V.S., Tiwari, P., 2019. Impact of natural surfactant (Reetha), polymer (xanthan gum), and silica nanoparticles to enhance heavy crude oil recovery. Energy & Fuels 33, 4225-4236.

Recent Sediments

Dan, S.F., Liu, S.-M., Yang, B., Udoh, E.C., Umoh, U., Ewa-Oboho, I., 2019. Geochemical discrimination of bulk organic matter in surface sediments of the Cross River estuary system and adjacent shelf, South East Nigeria (West Africa). Science of The Total Environment 678, 351-368.

Deininger, A., Frigstad, H., 2019. Reevaluating the role of organic matter sources for coastal eutrophication, oligotrophication, and ecosystem health. Frontiers in Marine Science 6, 210. doi: 210.3389/fmars.2019.00210.


Funkey, C.P., Conley, D.J., Stedmon, C.A., 2019. Sediment alkaline-extracted organic matter (AEOM) fluorescence: An archive of Holocene marine organic matter origins. Science of The Total Environment 676, 298-304.

Galoski, C.E., Jiménez Martínez, A.E., Schultz, G.B., dos Santos, I., Froehner, S., 2019. Use of n-alkanes to trace erosion and main sources of sediments in a watershed in southern Brazil. Science of The Total Environment 682, 447-456.

Lavrieux, M., Birkholz, A., Meusburger, K., Wiesenberg, G.L.B., Gilli, A., Stamm, C., Alewell, C., 2019. Plants or bacteria? 130 years of mixed imprints in Lake Baldegg sediments (Switzerland), as revealed by compound-specific isotope analysis (CSIA) and biomarker analysis. Biogeosciences 16, 2131-2146.

Lee, C., Love, G.D., Jahnke, L.L., Kubo, M.D., Des Marais, D.J., 2019. Early diagenetic sequestration of microbial mat lipid biomarkers through covalent binding into insoluble macromolecular organic matter (IMOM) as revealed by sequential chemolysis and catalytic hydropyrolysis. Organic Geochemistry 132, 11-22.

Liu, J., Song, J., Yuan, H., Li, X., Li, N., Duan, L., 2019. Biogenic matter characteristics, deposition flux correction, and internal phosphorus transformation in Jiaozhou Bay, North China. Journal of Marine Systems 196, 1-13.

Liu, S., Peng, X., 2019. Organic matter diagenesis in hadal setting: Insights from the pore-water geochemistry of the Mariana Trench sediments. Deep Sea Research Part I: Oceanographic Research Papers 147, 22-31.

Mukherjee, R., Muduli, P.R., Barik, S.K., Kumar, S., 2019. Sources and transformations of organic matter in sediments of Asia’s largest brackish water lagoon (Chilika, India) and nearby mangrove ecosystem. Environmental Earth Sciences 78, 332.

Nageswar Rao, M., Ram, A., Pradhan, U.K., Siddaiah, V., 2019. Factors controlling organic matter composition and trophic state in seven tropical estuaries along the west coast of India. Environmental Geochemistry and Health 41, 545-562.

Punshon, S., Azetsu-Scott, K., Sherwood, O., Edinger, E.N., 2019. Bottom water methane sources along the high latitude eastern Canadian continental shelf and their effects on the marine carbonate system. Marine Chemistry 212, 83-95.

Raven, M.R., Fike, D.A., Gomes, M.L., Webb, S.M., 2019. Chemical and isotopic evidence for organic matter sulfurization in redox gradients around mangrove roots. Frontiers in Earth Science 7, 98. doi: 10.3389/feart.2019.00098.

Shen, Y., Thiel, V., Suarez-Gonzalez, P., Rampen, S.W., Reitner, J., 2019. Sterol preservation in hypersaline microbial mats. Biogeosciences Discussions 2019, 1-28.

Shibini Mol, P.A., Sujatha, C.H., Krishnan, A., Deepak, K., Sruthy Mol, P.P., Priyanka, B.R., Dhanya, P.V., 2019. Spatial distribution of organic geochemical record in the core sediments along the prominent zones of Central Kerala, India. Environmental Forensics 20, 92-105.

Stevenson, M.A., Abbott, G.D., 2019. Exploring the composition of macromolecular organic matter in Arctic Ocean sediments under a changing sea ice gradient. Journal of Analytical and Applied Pyrolysis 140, 102-111.

Thibault, A., Derenne, S., Parlanti, E., Anquetil, C., Sourzac, M., Budzinski, H., Fuster, L., Laverman, A., Roose-Amsaleg, C., Viollier, E., Huguet, A., 2019. Dynamics of organic matter in the Seine Estuary (France): Bulk and structural approaches. Marine Chemistry 212, 108-119.


Wattripont, A., Baudin, F., de Rafelis, M., Deconinck, J.-F., 2019. Specifications for carbonate content quantification in recent marine sediments using Rock-Eval pyrolysis. Journal of Analytical and Applied Pyrolysis 140, 393-403.

ATMOSPHERIC GEOCHEMISTRY

Dall'Osto, M., Airs, R., Beale, R., Cree, C., Fitzsimons, M.F., Beddows, D.C.S., Harrison, R.M., Ceburnis, D., O'Dowd, C., Rinaldi, M., Paglione, M., Nenes, A., Decesari, S., Simo, R., 2019. Simultaneous detection of alkylamines in the surface ocean and atmosphere of the Antarctic sympagic environment. ACS Earth and Space Chemistry 3, 854-862.

Miyazaki, Y., Gowda, D., Tachibana, E., Takahashi, Y., Hiura, T., 2019. Identification of secondary fatty alcohols in atmospheric aerosols in temperate forests. Biogeosciences 16, 2181-2188.

Molteni, U., Simon, M., Heinritzi, M., Hoyle, C.R., Bernhammer, A.-K., Bianchi, F., Breitenlechner, M., Brilke, S., Dias, A., Duplissy, J., Frege, C., Gordon, H., Heyn, C., Jokinen, T., Kürten, A., Lehtipalo, K., Makhmutov, V., Petäjä, T., Pieber, S.M., Praplan, A.P., Schobesberger, S., Steiner, G., Stozhkov, Y., Tomé, A., Tröstl, J., Wagner, A.C., Wagner, R., Williamson, C., Yan, C., Baltensperger, U., Curtius, J., Donahue, N.M., Hansel, A., Kirkby, J., Kulmala, M., Worsnop, D.R., Dommen, J., 2019. Formation of highly oxygenated organic molecules from α-pinene ozonolysis: Chemical characteristics, mechanism, and kinetic model development. ACS Earth and Space Chemistry 3, 873-883.


Sovová, K., Spesyvyi, A., Bursová, M., Pásztor, P., Kubišta, J., Shestivska, V., Španěl, P., 2019. Time-integrated thermal desorption for quantitative SIFT-MS analyses of atmospheric monoterpenes. Analytical and Bioanalytical Chemistry 411, 2997-3007.

HYDROSPHERE GEOCHEMISTRY




Csank, A.Z., Czimczik, C.I., Xu, X., Welker, J.M., 2019. Seasonal patterns of riverine carbon sources and export in NW Greenland. Journal of Geophysical Research: Biogeosciences 124, 840-856.



Geraldi, N.R., Ortega, A., Serrano, O., Macreadie, P.I., Lovelock, C.E., Krause-Jensen, D., Kennedy, H., Lavery, P.S., Pace, M.L., Kaal, J., Duarte, C.M., 2019. Fingerprinting blue carbon: Rationale and tools to determine the source of organic carbon in marine depositional environments. Frontiers in Marine Science 6, 263. doi: 210.3389/fmars.2019.00263.


Kang, M., He, L., Fan, D., Chen, J., Jia, G., 2019. Assessment of sedimentary heterocyst glycolipids as tracers of freshwater input to the Changjiang Estuary and East China Sea. Chemical Geology 521, 39-48.

Kida, M., Tanabe, M., Tomotsune, M., Yoshitake, S., Kinjo, K., Ohtsuka, T., Fujitake, N., 2019. Changes in dissolved organic matter composition and dynamics in a subtropical mangrove river driven by rainfall. Estuarine, Coastal and Shelf Science 223, 6-17.

Laruelle, G.G., Marescaux, A., Le Gendre, R., Garnier, J., Rabouille, C., Thieu, V., 2019. Carbon dynamics along the Seine River network: Insight from a coupled estuarine/river modeling approach. Frontiers in Marine Science 6, 216. doi: 210.3389/fmars.2019.00216.

Pavia, F.J., Anderson, R.F., Lam, P.J., Cael, B.B., Vivancos, S.M., Fleisher, M.Q., Lu, Y., Zhang, P., Cheng, H., Edwards, R.L., 2019. Shallow particulate organic carbon regeneration in the South Pacific Ocean. Proceedings of the National Academy of Sciences 116, 9753-9758.

Sarma, V.V.S.S., Sampath Kumar, G., Yadav, K., Dalabehera, H.B., Rao, D.N., Behera, S., Loganathan, J., 2019. Impact of eddies on dissolved inorganic carbon components in the Bay of Bengal. Deep Sea Research Part I: Oceanographic Research Papers 147, 111-120.

Stukel, M.R., Kelly, T.B., Aluwihare, L.I., Barbeau, K.A., Goericke, R., Krause, J.W., Landry, M.R., Ohman, M.D., 2019. The Carbon:234Thorium ratios of sinking particles in the California current ecosystem 1: relationships with plankton ecosystem dynamics. Marine Chemistry 212, 1-15.

Suh, Y.J., Diefendorf, A.F., Bowen, G.J., Cotton, J.M., Ju, S.-J., 2019. Plant wax integration and transport from the Mississippi River Basin to the Gulf of Mexico inferred from GIS-enabled isoscapes and mixing models. Geochimica et Cosmochimica Acta 257, 131-149.

Wagner, S., Fair, J.H., Matt, S., Hosen, J.D., Raymond, P., Saiers, J., Shanley, J.B., Dittmar, T., Stubbins, A., 2019. Molecular hysteresis: Hydrologically driven changes in riverine dissolved organic matter chemistry during a storm event. Journal of Geophysical Research: Biogeosciences 124, 759-774.



SOIL GEOCHEMISTRY

Kuhry, P., Bárta, J., Blok, D., Elberling, B., Faucherre, S., Hugelius, G., Richter, A., Šantrůčková, H., Weiss, N., 2019. Lability classification of soil organic matter in the northern permafrost region. Biogeosciences Discussions 2019, 1-30.


Piaszczyk, W., Błońska, E., Lasota, J., Lukac, M., 2019. A comparison of C:N:P stoichiometry in soil and deadwood at an advanced decomposition stage. CATENA 179, 1-5.


Steinmuller, H.E., Chambers, L.G., 2019. Characterization of coastal wetland soil organic matter: Implications for wetland submergence. Science of The Total Environment 677, 648-659.


Remote Sensing-Hydrocarbon Seepage


Böttner, C., Berndt, C., Reinardy, B.T.I., Geersen, J., Karstens, J., Bull, J.M., Callow, B.J., Lichtschlag, A., Schmidt, M., Elger, J., Schramm, B., Haeckel, M., 2019. Pockmarks in the

Witch Ground Basin, Central North Sea. Geochemistry, Geophysics, Geosystems 20, 1698-1719.

Farhadian Babadi, M., Mehrabi, B., Tassi, F., Cabassi, J., Vaselli, O., Shakeri, A., Pecchioni, E., Venturi, S., Zelenski, M., Chaplygin, I., 2019. Origin of fluids discharged from mud volcanoes in SE Iran. Marine and Petroleum Geology 106, 190-205.


Liu, X., Feng, X., Sun, Y., Chen, Y., Tang, Q., Zhou, X., Dong, L., Fan, S., Jiao, P., Wang, K., Wen, W., Lu, B., 2019. Acoustic and biological characteristics of seafloor depressions in the North Yellow Sea Basin of China: Active fluid seepage in shallow water seafloor. Marine Geology 414, 34-46.

Padilla, A.M., Loranger, S., Kinnaman, F.S., Valentine, D.L., Weber, T.C., 2019. Modern assessment of natural hydrocarbon gas flux at the Coal Oil Point Seep Field, Santa Barbara, California. Journal of Geophysical Research: Oceans 124, 2472-2484.

Roy, S., Senger, K., Hovland, M., Römer, M., Braathen, A., 2019. Geological controls on shallow gas distribution and seafloor seepage in an Arctic fjord of Spitsbergen, Norway. Marine and Petroleum Geology 107, 237-254.


Tamborrino, L., Himmler, T., Elvert, M., Conti, S., Gualtieri, A.F., Fontana, D., Bohrmann, G., 2019. Formation of tubular carbonate conduits at Athina mud volcano, eastern Mediterranean Sea. Marine and Petroleum Geology 107, 20-31.


Witkowski, C.R., Agostini, S., Harvey, B.P., van der Meer, M.T.J., Sinninghe Damsté, J.S., Schouten, S., 2019. Validation of carbon isotope fractionation in algal lipids as a PCO2 proxy using a natural CO2 seep (Shikine Island, Japan). Biogeosciences Discussions 2019, 1-18.

Source Rocks/Depositional Environments

Adekeye, O.A., Akande, S.O., Adeoye, J.A., 2019. The assessment of potential source rocks of Maastrichtian Araromi Formation in Araromi and Gbekebo wells Dahomey Basin, southwestern Nigeria. Heliyon 5, e01561.

Al-Saad, H., Al-Khafaji, A.J., Sadooni, F.N., 2019. Evaluation of the source rock potential of the Unyazah Formation (late Carboniferous-Early Permian) in Dukhan Field, Qatar. Petroleum Science and Technology 37, 1655-1664.

Alhesan, J.S.A., Marshall, M., Jackson, W.R., Qi, Y., Cassidy, P.J., Chaffee, A.L., 2019. Isolation of organic matter by the NaOH-HCl method from two marine oil shales using oven and sealed autoclave techniques. Oil Shale 3, 197-213.

Amer, M.W., Aljariri Alhesan, J.S., Marshall, M., Awwad, A.M., Al-Ayed, O.S., 2019. Characterization of Jordanian oil shale and variation in oil properties with pyrolysis temperature. Journal of Analytical and Applied Pyrolysis 140, 219-226.

Ding, X., Qu, J., Imin, A., Zha, M., Su, Y., Jiang, Z., Jiang, H., 2019. Organic matter origin and accumulation in tuffaceous shale of the lower Permian Lucaogou Formation, Jimsar Sag. Journal of Petroleum Science and Engineering 179, 696-706.


Fang, X., Wu, L., Geng, A., Deng, Q., 2019. Formation and evolution of the Ediacaran to Lower Cambrian black shales in the Yangtze Platform, South China. Palaeogeography, Palaeoclimatology, Palaeoecology 527, 87-102.

Gentzis, T., Carvajal-Ortiz, H., Tahoun, S.S., Deaf, A., Ocubalidet, S., 2019. Organic facies and hydrocarbon potential of the early-middle Albian Kharita Formation in the Abu Gharadig Basin, Egypt, as demonstrated by palynology, organic petrology, and geochemistry. International Journal of Coal Geology 209, 27-39.

Grohmann, S., Romero-Sarmiento, M.-F., Nader, F.H., Baudin, F., Littke, R., 2019. Geochemical and petrographic investigation of Triassic and Late Miocene organic-rich intervals from onshore Cyprus, Eastern Mediterranean. International Journal of Coal Geology 209, 94-116.

Guo, P., Liu, C., Wang, L., Zhang, G., Fu, X., 2019. Mineralogy and organic geochemistry of the terrestrial lacustrine pre-salt sediments in the Qaidam Basin: Implications for good source rock development. Marine and Petroleum Geology 107, 149-162.

Hakimi, M.H., Abdullah, W.H., Hersi, O.S., Lashin, A.A., El Alfy, M.M., Makeen, Y.M., Kinawy, M.M., Hatem, B.A., 2019. Organic geochemistry of the Early Cretaceous shales, Saar Formation in the East Shabwah oil fields, onshore Masila Basin of eastern Yemen. Journal of Petroleum Science and Engineering 179, 394-409.

Hakimi, M.H., Alaug, A.S., Lashin, A.A., Mohialdeen, I.M.J., Yahya, M.M.A., Kinawy, M.M., 2019. Geochemical and geological modeling of the Late Jurassic Meem Shale Member in the Al-Jawf sub-basin, Yemen: Implications for regional oil and gas exploration. Marine and Petroleum Geology 105, 313-330.

Hazra, B., Karacan, C.Ö., Tiwari, D.M., Singh, P.K., Singh, A.K., 2019. Insights from Rock-Eval analysis on the influence of sample weight on hydrocarbon generation from Lower Permian organic matter rich rocks, West Bokaro basin, India. Marine and Petroleum Geology 106, 160-170.

Hennissen, J.A.I., Gent, C.M.A., 2019. Total organic carbon in the Bowland-Hodder Unit of the southern Widmerpool Gulf: a discussion. Journal of Petroleum Science and Engineering 178, 1194-1202.


Knapp, L.J., Harris, N.B., McMillan, J.M., 2019. A sequence stratigraphic model for the organic-rich Upper Devonian Duvernay Formation, Alberta, Canada. Sedimentary Geology 387, 152-181.

Kouketsu, Y., Tsai, C.-H., Enami, M., 2019. Discovery of unusual metamorphic temperatures in the Yuli belt, eastern Taiwan: New interpretation of data by Raman carbonaceous material geothermometry. Geology 47, 522-526.

Li, Z., Huang, H., He, C., Fang, X., 2019. Maturation impact on polyaromatic hydrocarbons and organosulfur compounds in the Carboniferous Keluke Formation from Qaidam Basin, NW China. Energy & Fuels 33, 4115-4129.


Lu, Y., Huang, C., Jiang, S., Zhang, J., Lu, Y., Liu, Y., 2019. Cyclic late Katian through Hirnantian glacioeustasy and its control of the development of the organic-rich Wufeng and Longmaxi shales, South China. Palaeogeography, Palaeoclimatology, Palaeoecology 526, 96-109.

Luo, Q., Xiao, Z., Dong, C., Ye, X., Li, H., Zhang, Y., Ma, Y., Ma, L., Xu, Y., 2019. The geochemical characteristics and gas potential of the Longtan Formation in the eastern Sichuan Basin, China. Journal of Petroleum Science and Engineering 179, 1102-1113.

McArthur, J.M., 2019. Early Toarcian black shales: A response to an oceanic anoxic event or anoxia in marginal basins? Chemical Geology 522, 71-83.

Naeher, S., Hollis, C.J., Clowes, C.D., Ventura, G.T., Shepherd, C.L., Crouch, E.M., Morgans, H.E.G., Bland, K.J., Strogen, D.P., Sykes, R., 2019. Depositional and organofacies influences on the petroleum potential of an unusual marine source rock: Waipawa Formation (Paleocene) in southern East Coast Basin, New Zealand. Marine and Petroleum Geology 104, 468-488.


Petty, D.M., 2019. An alternative interpretation for the origin of black shale in the Bakken Formation of the Williston Basin. Bulletin of Canadian Petroleum Geology 67, 47-70.

Richiano, S., Gómez-Peral, L.E., Varela, A.N., Gómez Dacal, A.R., Cavarozzi, C.E., Poiré, D.G., 2019. Geochemical characterization of black shales from the Río Mayer Formation (Early Cretaceous), Austral-Magallanes Basin, Argentina: Provenance response during Gondwana break-up. Journal of South American Earth Sciences 93, 67-83.

Schreuder, L.T., Donders, T.H., Mets, A., Hopmans, E.C., Sinninghe Damsté, J.S., Schouten, S., 2019. Comparison of organic and palynological proxies for biomass burning and vegetation in a lacustrine sediment record (Lake Allom, Fraser Island, Australia). Organic Geochemistry 133, 10-19.

Sun, T., Bake, K.D., Craddock, P.R., Gunawan, B., Darnell, L.M., Bissada, K.K., Pomerantz, A.E., 2019. Acid demineralization with pyrite removal and critical point drying for kerogen microstructural analysis. Fuel 253, 266-272.

Tian, T., Zhou, S., Fu, D., Yang, F., Li, J., 2019. Calculation of the original abundance of organic matter at high-over maturity: A case study of the Lower Cambrian Niutitang shale in the Micangshan-Hannan Uplift, SW China. Journal of Petroleum Science and Engineering 179, 645-654.

Tserolas, P., Maravelis, A.G., Tsochandaris, N., Pasadakis, N., Zelilidis, A., 2019. Organic geochemistry of the Upper Miocene-Lower Pliocene sedimentary rocks in the Hellenic Fold and Thrust Belt, NW Corfu island, Ionian sea, NW Greece. Marine and Petroleum Geology 106, 17-29.

Wang, K., Zhang, H., Han, X., Qiu, W., 2019. Sources and burial fluxes of sedimentary organic carbon in the northern Bering Sea and the northern Chukchi Sea in response to global warming. Science of The Total Environment 679, 97-105.

Wang, Y., Liu H., Song, G., Xiong, W., Zhu, D., Zhu, D., Yin, Y., Ding, J., Yang, W., Zhang, L., Zhang, S., 2019. Lacustrine shale fine-grained sedimentary system in Jiyang depression Acta Petrolei Sinica 40, 395-410.

Yang, S., Schulz, H.-M., Schovsbo, N., Mayanna, S., 2019. The organic geochemistry of “Kolm”, a unique analogue for the understanding of molecular changes after significant uranium irradiation. International Journal of Coal Geology 209, 89-93.


Zhang, R., Jin, Z., Liu, Q., Li, P., Huang, Z., Shi, J., Ge, Y., Du, K., 2019. Astronomical constraints on deposition of the Middle Triassic Chang 7 lacustrine shales in the Ordos Basin, Central China. Palaeogeography, Palaeoclimatology, Palaeoecology 528, 87-98.

Zhang, T., Wang, Z., Wang, Y., Wei, Z., Li, X., Hou, X., Sun, Z., Wang, G., Qian, Y., 2019. The characteristics of free/bound biomarkers released from source rock shown by stepwise Py-GC-MS and thermogravimetric analysis (TGA/DTG). Journal of Petroleum Science and Engineering 179, 526-538.

Zhao, K., Du, X., Lu, Y., Xiong, S., Wang, Y., 2019. Are light-dark coupled laminae in lacustrine shale seasonally controlled? A case study using astronomical tuning from 42.2 to 45.4 Ma in the Dongying Depression, Bohai Bay Basin, eastern China. Palaeogeography, Palaeoclimatology, Palaeoecology 528, 35-49.

Zhu, M., Li, M., Wei, S., Song, J., Hu, J., Jia, W., Peng, P.a., 2019. Evaluation of a dichromate oxidation method for the isolation and quantification of black carbon in ancient geological samples. Organic Geochemistry 133, 20-31.

Unconventional Resources

Bi, R., Nasrabadi, H., 2019. Molecular simulation of the constant composition expansion experiment in shale multi-scale systems. Fluid Phase Equilibria 495, 59-68.



Dong, T., He, S., Chen, M., Hou, Y., Guo, X., Wei, C., Han, Y., Yang, R., 2019. Quartz types and origins in the Paleozoic Wufeng-Longmaxi Formations, Eastern Sichuan Basin, China: Implications for porosity preservation in shale reservoirs. Marine and Petroleum Geology 106, 62-73.

Fu, C., Liu, N., 2019. Waterless fluids in hydraulic fracturing – A review. Journal of Natural Gas Science and Engineering 67, 214-224.


Huang, J., Jin, T., Chai, Z., Barrufet, M., Killough, J., 2019. Compositional simulation of fractured shale reservoir with distribution of nanopores using coupled multi-porosity and EDFM method. Journal of Petroleum Science and Engineering 179, 1078-1089.


Liang, F., Zhang, J., Liu, H.-H., Bartko, K.M., 2019. Multiscale experimental studies on interactions between aqueous-based fracturing fluids and tight organic-rich carbonate source rocks. SPE-190325-PA 22, 402-417.

Liu, C., Liu, K., Wang, X., Wu, L., Fan, Y., 2019. Chemostratigraphy and sedimentary facies analysis of the Permian Lucaogou Formation in the Jimusaer Sag, Junggar Basin, NW China: Implications for tight oil exploration. Journal of Asian Earth Sciences 178, 96-111.


Liu, Y., Ma, X., Li, H.A., Hou, J., 2019. Competitive adsorption behavior of hydrocarbon(s)/CO2

mixtures in a double-nanopore system using molecular simulations. Fuel 252, 612-621.

Nikolaev, M.Y., Kazak, A.V., 2019. Liquid saturation evaluation in organic-rich unconventional reservoirs: A comprehensive review. Earth-Science Reviews 194, 327-349.

Pilewski, J., Sharma, S., Agrawal, V., Hakala, J.A., Stuckman, M.Y., 2019. Effect of maturity and mineralogy on fluid-rock reactions in the Marcellus Shale. Environmental Science: Processes & Impacts 21, 845-855.

Rijfkogel, L.S., Ghanbarian, B., Hu, Q., Liu, H.-H., 2019. Clarifying pore diameter, pore width, and their relationship through pressure measurements: A critical study. Marine and Petroleum Geology 107, 142-148.

Sermoud, V.M., Barbosa, G.D., Barreto, A.G., Tavares, F.W., 2019. Reconstruction of the pore size distribution of porous materials: The influence of uncertainties in the gaseous adsorption experimental data. Fluid Phase Equilibria 494, 93-102.


Sun, L., Tuo, J., Zhang, M., Wu, C., Chai, S., 2019. Pore structures and fractal characteristics of nano-pores in shale of Lucaogou Formation from Junggar Basin during water pressure-controlled artificial pyrolysis. Journal of Analytical and Applied Pyrolysis 140, 404-412.


Tang, X., Zhou, X., Peng, Y., 2019. Molecular simulation of methane adsorption within illite minerals in the Longmaxi Formation shale based on a grand canonical Monte Carlo method and the pore size distribution in southeastern Chongqing, China. Journal of Natural Gas Geoscience 4, 111-119.

Wang, J., Ryan, D., Szabries, M., Jaeger, P., 2019. A study for using CO2 to enhance natural gas recovery from tight reservoirs. Energy & Fuels 33, 3821-3827.

Wang, Y., Liu, L., Zheng, S., Luo, Z., Sheng, Y., Wang, X., 2019. Full-scale pore structure and its controlling factors of the Wufeng-Longmaxi shale, southern Sichuan Basin, China: Implications for pore evolution of highly overmature marine shale. Journal of Natural Gas Science and Engineering 67, 134-146.

Wu, S., Zhu, R., Yang, Z., Mao, Z., Cui, J., Zhang, X., 2019. Distribution and characteristics of lacustrine tight oil reservoirs in China. Journal of Asian Earth Sciences 178, 20-36.



Xu, Z., Liu, L., Liu, B., Wang, T., Zhang, Z., Wu, K., Feng, C., Dou, W., Wang, Y., Shu, Y., 2019. Geochemical characteristics of the Triassic Chang 7 lacustrine source rocks, Ordos Basin, China: Implications for paleoenvironment, petroleum potential and tight oil occurrence. Journal of Asian Earth Sciences 178, 112-138.

Yin, S., Xie, R., Zhao, J., 2019. Analysis of adsorption kinetics and thermodynamics of methane in shale based on the volume filling theory of micropores. International Journal of Oil, Gas and Coal Technology 21, 26-38.

Yu, W., Zhang, Y., Varavei, A., Sepehrnoori, K., Zhang, T., Wu, K., Miao, J., 2019. Compositional aimulation of CO2 huff ‘n’ puff in Eagle Ford tight oil reservoirs with CO2 molecular diffusion, nanopore confinement, and complex natural fractures. SPE-190325-PA 22, 492-508.

Zha, M., Wang, S., Ding, X., Feng, Q., Xue, H., Su, Y., 2019. Tight oil accumulation mechanisms of the Lucaogou Formation in the Jimsar Sag, NW China: Insights from pore network modeling and physical experiments. Journal of Asian Earth Sciences 178, 204-215.


Zhao, W., Zhang, S., He, K., Zeng, H., Hu, G., Zhang, B., Wang, Z., Li, Y., 2019. Origin of conventional and shale gas in Sinian–lower Paleozoic strata in the Sichuan Basin: Relayed gas generation from liquid hydrocarbon cracking. American Association of Petroleum Geologist Bulletin 103, 1265-1296.

Zhou, S., Zhang, D., Wang, H., Li, X., 2019. A modified BET equation to investigate supercritical methane adsorption mechanisms in shale. Marine and Petroleum Geology 105, 284-292.

Zhu, R., Zou, C., Mao, Z., Yang, H., Hui, X., Wu, S., Cui, J., Su, L., Li, S., Yang, Z., 2019. Characteristics and distribution of continental tight oil in China. Journal of Asian Earth Sciences 178, 37-51.

Zou, C., Yang, Z., Zhu, R., Wu, S., Fu, J., Lei, D., Hou, L., Lin, S., Pan, S., 2019. Geologic significance and optimization technique of sweet spots in unconventional shale systems. Journal of Asian Earth Sciences 178, 3-19.

Abstracts


https://doi.org/10.1021/acs.analchem.9b00854

Multimodal integration between mass spectrometry imaging (MSI) and radiology-established modalities such as magnetic resonance imaging (MRI) would allow the investigations of key questions in complex biological systems such as the central nervous system. Such integration would provide complementary multiscale data to bridge the gap between molecular and anatomical phenotypes, potentially revealing new insights into molecular mechanisms underlying anatomical pathologies presented on MRI. Automatic coregistration between 3D MSI/MRI is a computationally challenging process due to dimensional complexity, MSI data sparsity, lack of direct spatial-

correspondences, and nonlinear tissue deformation. Here, we present a new computational approach based on stochastic neighbor embedding to nonlinearly align 3D MSI to MRI data, identify and reconstruct biologically relevant molecular patterns in 3D, and fuse the MSI datacube to the MRI space. We demonstrate our method using multimodal high-spectral resolution matrix-assisted laser desorption ionization (MALDI) 9.4 T MSI and 7 T in vivo MRI data, acquired from a patient-derived, xenograft mouse brain model of glioblastoma following administration of the EGFR inhibitor drug of Erlotinib. Results show the distribution of some identified molecular ions of the EGFR inhibitor erlotinib, a phosphatidylcholine lipid, and cholesterol, which were reconstructed in 3D and mapped to the MRI space. The registration quality was evaluated on two normal mouse brains using the Dice coefficient for the regions of brainstem, hippocampus, and cortex. The method is generic and can therefore be applied to hyperspectral images from different mass spectrometers and integrated with other established in vivo imaging modalities such as computed tomography (CT) and positron emission tomography (PET).


http://www.sciencedirect.com/science/article/pii/S0016236119308063

Asphaltenes are n-alkane insoluble compounds found in crude oils and heavy fuels (high and non-boiling petroleum fractions). Asphaltene molecular structure has not been fully elucidated, and their presence in fuels is a source of concern. They reduce combustion efficiency and are responsible for particulate matter emissions. Removing the asphaltenes, or deasphalting, is a way of upgrading the fuel to improve its quality. This study reports the removal of asphaltenes from heavy fuel oil (HFO) using a solvent extraction method, and the detailed molecular characterization of the deasphalted oil (DAO) using positive ion atmospheric pressure photo ionization Fourier transform-ion cyclotron resonance mass spectrometry (APPI (+) FT-ICR/MS) and 1H and 13C Nuclear magnetic resonance (NMR) spectroscopy. Approximately 8.2 mass % of asphaltenes were removed from HFO using n-heptane as solvent. This resulted in significant improvements in the HFO’s physical properties. The resulting DAO was five times less viscous and contained significantly less heavy metals (e.g., Ni and V). There was also a slight reduction in the sulfur content from 3.3 to 3.1 mass %. 52,753 and 46,315 ions with a mass to charge ratio (m/z) ranging from 154 to 1200 were detected in HFO and DAO samples, respectively, using APPI FT-ICR/MS. Amongst them, 6729 (HFO) and 6030 (DAO) ions were resolved into their underlying elemental compositions (C, H, O, N and S) and a unique chemical formula was assigned to each mass. The resolved masses were then further classified based on their molecular class and were analyzed as a function of double bond equivalent (DBE) vs carbon number. 1H and 13C NMR analyses of HFO and DAO were performed and the results indicate the total aromatic groups in HFO (1H 7.7 mol %, 13C 37.6 mol %) are more compared to DAO (1H 4.7 mol %, 13C 32.6 mol %). The average molecular parameters (AMPs) of HFO and DAO were also calculated from the 1H and 13C NMR spectra and compared. A surrogate molecule that visualizes the average molecular structure of the entire fuel was developed for both HFO and DAO using the data from the above analytical techniques. Understanding the molecular chemistry of these fuels provides valuable data to develop better desulfurization techniques for these sulfur laden fuels and help predict fuel properties using structure-property relationships.

Abutaqiya, M.I.L., Sisco, C.J., Wang, J., Vargas, F.M., 2019. Systematic investigation of asphaltene deposition in the wellbore and near-wellbore region of a deepwater oil reservoir under gas injection. Part 1: Thermodynamic modeling of the phase behavior of polydisperse asphaltenes. Energy & Fuels 33, 3632-3644.

https://doi.org/10.1021/acs.energyfuels.8b03234

Thermodynamic modeling is conducted for a high-asphaltene, high-resin crude oil produced from a deepwater reservoir using the perturbed-chain statistical associating fluid theory (PC-SAFT). The asphaltenes are characterized as a polydisperse fraction following a three-parameter Γ distribution function with resins included as the lightest cut of the asphaltene distribution. Modeling results with 55 mol % injection indicate that the driving force of precipitation is sufficiently large that a significant amount of non-asphaltene components co-precipitate with asphaltenes. As pressure decreases from the upper asphaltene onset pressure (UAOP) to the bubble pressure (BP), the amount (by weight) of the asphaltene-rich phase surpasses the amount of the asphaltene-lean phase. Interestingly, as pressure decreases below the BP, the asphaltene-lean phase dissolves into the asphaltene-rich phase until the pressure reaches the lower onset pressure, where the lean phase is completely dissolved. As a result of the high driving force of precipitation, all asphaltenes precipitate out of solution before the BP and significant amounts of the other pseudo-fractions also co-precipitate. This causes the composition of asphaltenes in the asphaltene-rich phase to decrease as the pressure decreases, and the asphaltene composition in the asphaltene-rich phase at the upper onset is 23.6 wt %, which is uncommonly low for a precipitating phase. Experimental images from high-pressure microscopy show that the shape of the formed asphaltene-rich phase changes from a rigid solid-like structure near the UAOP to a soft liquid-like structure as the pressure decreases. This indicates a decrease in asphaltene composition during depressurization, similar to the simulation results produced by PC-SAFT. A sensitivity analysis is performed to evaluate the assumption of poly- and monodisperse asphaltenes from a modeling perspective and the effect of the Γ distribution parameters.

Adekeye, O.A., Akande, S.O., Adeoye, J.A., 2019. The assessment of potential source rocks of Maastrichtian Araromi Formation in Araromi and Gbekebo wells Dahomey Basin, southwestern Nigeria. Heliyon 5, e01561.


Drilled core samples of the Araromi Formation in the eastern Dahomey basin penetrated by Araromi and Gbekebo exploratory wells were investigated to establish the source rocks potentials in the onshore area of the basin. The sediments are of Maastrichtian age deposited in the shallow marine environment with varying thicknesses.

Rock-Eval data of forty seven (40) shales give Total Organic Carbon (TOC) range of 0.50–4.78 wt%, Hydrogen Index (HI) value range of 1 - 327mgHC/gTOC, Tmax values from 398 °C–437 °C and Source Potential (SP) values range from 0.01 - 14.56kgHC/ton of rock. The maceral compositions of the shales are liptinite (av. 26.0%), abundance vitrinite (av. 38.1%) and inertinite (av. 35.9 %) with vitrinite reflectance (VRo) ranging from 0.51 - 0.68 %Ro. Hydrocarbons and biomarkers results reveal a bimodal n-alkane envelope between (nC16 and nC18) and (nC27 and nC29) suggesting organic matter of mixed origin of algae and higher plant generally in the two well. The Significant contribution of marine algae in the deeper part of Gbekebo well was observed by the presence of C30 24-n-propyl cholestane (%C30 sterane range from 0.45 to as high as 5.23%).

Integration of the Rock-Eval, organic petrology and biomarkers data reveal that the kerogen constituents of the source rocks in Araromi well are mainly Type II/III, III and IV with a high amount of inertinite constituents suggesting they have been reworked. Type II and II/III kerogen derived from marine algae are better preserved in the deeper part of Gbekebo well located more southerly in the basin than in the Araromi well. The source rocks are generally immature to marginally mature and hydrocarbon exploration effort should be targeted towards Gbekebo well area where we have more

promising potential source rocks capable of generating more hydrocarbons essentially at a deeper depth.

Adeleye, A.S., Ho, K.T., Zhang, M., Li, Y., Burgess, R.M., 2019. Fate and transformation of graphene oxide in estuarine and marine waters. Environmental Science & Technology 53, 5858-5867.

https://doi.org/10.1021/acs.est.8b06485

The possibility of graphene oxide (GO) exposure to the environment has spurred several studies investigating the fate of this nanoparticle (NP). However, there is currently little or no data on the fate of GO in estuarine and marine waters. This study investigated the aggregation, sedimentation, and transformation of GO in saline waters, considering the roles of salinity (0–50 ‰), light (visible light and solar irradiation), and aging, among others. The attachment efficiency of GO reached unity at 1.33 ‰. The sedimentation rate of GO increased with salinity up to 10 ‰ after which it decreased due to formation of ramified GO agglomerates and media density. On the basis of the sedimentation rate determined at 30 ‰ (0.121 m/d), the residence time of GO agglomerates in the euphotic zone of typical open oceans will exceed 500 days. Aging in the presence of visible light increased the relative abundance of the GO’s aromatic (C–C/C=C) fraction, reducing the NP. Reduction of GO in visible light was confirmed via UV–vis and Raman spectroscopic techniques. Reduction of GO was faster under solar irradiation. This study demonstrates that when introduced into saline waters, GO will undergo a range of transformations affecting its fate and potential effects to aquatic organisms.


https://www.frontiersin.org/article/10.3389/fmicb.2019.00779

The Yilgarn Craton in Australia has a large number of naturally occurring shallow ephemeral lakes underlain by a dendritic system of paleodrainage channels. Processes like evaporation, flooding, erosion, as well as inflow of saline, often acidic and ion-rich groundwater contribute to the (dynamic) nature of the lakes and the composition of the sediments. The region has previously been described as an analogue environment for early Mars due to its geological and geophysical similarities. Here, we investigated sediment samples of four lake environments aimed at getting a fundamental understanding of the native microbial communities and the mineralogical and (bio)chemical composition of the sediments they are associated with. The dominant mineral phases in the sediments were quartz, feldspars and amphiboles, while halite and gypsum were the only evaporites detected. Element analysis revealed a rich and complex image, in which silicon, iron and aluminum were the dominant ions, but relative high concentrations of trace elements such as strontium, chromium, zirconium and barium were also found. The concentrations of organic carbon, nitrogen and phosphorus were generally low. 16S amplicon sequencing on the Illumina platform showed the presence of diverse microbial communities in all four lake environments. We found that most of the communities were dominated by extremely halophilic Archaea of the Halobacteriaceae family. The dynamic nature of these lakes appears to influence the biological, biochemical and geological components of the ecosystem to a large effect. Inter- and intra-lake variations in the distributions of microbial communities were significant, and could only to a minor degree be explained by underlying environmental conditions. The communities are likely significantly influenced by small scale local effects caused by variations in geological settings and dynamic interactions caused by aeolian transport and flooding and evaporation events.

Agi, A., Junin, R., Shirazi, R., Afeez, G., Yekeen, N., 2019. Comparative study of ultrasound assisted water and surfactant flooding. Journal of King Saud University - Engineering Sciences 31, 296-303.

https://www.sciencedirect.com/science/article/pii/S1018363917302052

Ultrasound technique is an economic advantageous and environmental friendly unconventional enhanced oil recovery (EOR) method that has been of great interest to researchers and reservoir engineers. The integration of ultrasound with water flooding and ultrasound with surfactant has been proven to be effective in increasing oil recovery by decreasing surfactant adsorption. Previous studies focused on the phase behaviour of surfactant-brine-oil to determine if ultrasonic with surfactant can actually decrease the rate of surfactant consumption. However, phase behaviour alone cannot answer this question. In this study therefore, the role of critical micelle concentration (CMC) in ultrasound assisted surfactant flooding, and the effect of surfactant concentration on oil recovery during ultrasound at different intensities were investigated. An unconsolidated sand-pack model placed inside an ultrasonic bath and ultrasonic radiation was used for this purpose. Ultrasound assisted water and surfactant flooding improve recovery up to 11% and 12% respectively. The formation of micro-emulsion (micelles) during surfactant flooding in the presence of ultrasonic wave was the most significant mechanism responsible for the increased recovery. Ultrasound vibration is more efficient at higher concentration of surfactant, preferably above CMC and at higher intensity of ultrasound.

Ahlberg, P., Lundberg, F., Erlström, M., Calner, M., Lindskog, A., Dahlqvist, P., Joachimski, M.M., 2019. Integrated Cambrian biostratigraphy and carbon isotope chemostratigraphy of the Grönhögen-2015 drill core, Öland, Sweden. Geological Magazine 156, 935-949.

https://doi.org/10.1017/S0016756818000298

The Grönhögen-2015 core drilling on southern Öland, Sweden, penetrated 50.15 m of Cambrian Series 3, Furongian and Lower–Middle Ordovician strata. The Cambrian succession includes the Äleklinta Member (upper Stage 5) of the Borgholm Formation and the Alum Shale Formation (Guzhangian–Tremadocian). Agnostoids and trilobites allowed subdivision of the succession into eight biozones, in ascending order: the uppermost Cambrian Series 3 (Guzhangian) Agnostus pisiformis Zone and the Furongian Olenus gibbosus, O. truncatus, Parabolina spinulosa, Sphaerophthalmus? flagellifer, Ctenopyge tumida, C. linnarssoni and Parabolina lobata zones. Conspicuous lithologic unconformities and the biostratigraphy show that the succession is incomplete and that there are several substantial gaps of variable magnitudes. Carbon isotope analyses (δ13Corg) through the Alum Shale Formation revealed two globally significant excursions: the Steptoean Positive Carbon Isotope Excursion (SPICE) in the lower–middle Paibian Stage, and the negative Top of Cambrian Excursion (TOCE), previously referred to as the HERB Event, in Stage 10. The δ13Corg chemostratigraphy is tied directly to the biostratigraphy and used for an improved integration of these excursions with the standard agnostoid and trilobite zonation of Scandinavia. Their relations to that of coeval successions in Baltoscandia and elsewhere are discussed. The maximum amplitudes of the SPICE and TOCE in the Grönhögen succession are comparable to those recorded in drill cores retrieved from Scania, southern Sweden. The results of this study will be useful for assessing biostratigraphic relations between shale successions and carbonate facies on a global scale.

Ahmed, O.E., Eldesoky, A.M., El Nady, M.M., 2019. Oil hydrocarbon fingerprints of the different marine organisms in some Egyptian Gulf of Suez waters. Petroleum Science and Technology 37, 1722-1730.

https://doi.org/10.1080/10916466.2019.1602644

Oil hydrocarbon fingerprints derived from polycyclic aromatic and aliphatic hydrocarbon were analyzed in marine organisms of various aquatic species muscles collected from 10 different sites along Suez Gulf, Egypt. All samples were analyzed for n-alkanes (C15–C37) and polycyclic aromatic hydrocarbons (EPA list of PAHs). n-Alkanes in ten aquatic species were found to be in the range of 11.391–96.747 ng/g wet weight with a mean value of 60.755 ng/g wet weights. Different indices were calculated for the n-alkanes to assess their sources as carbon preference index (CPI), average chain length (ACL), terrigenous/aquatic ratio (TAR), natural n-alkane ratio (NAR) and proxy ratio (Paq). Most of the various species of n-alkanes were discovered to be from natural sources. Polycyclic aromatic hydrocarbons (PAHs) varied between 81.499 and 5895.608 ng/g wet weight with an average of 2521.126 ng/g wet weight. The contents of ƩPAHs were the highest in the tissues. The carcinogenic risks for humans from residual ƩPAHs in the various fish tissues higher than10−5.



The remediation of oil sand process-affected water (OSPW) generated during the bitumen extraction in the oil sand region of Canada is an area of ongoing research interest. One of the primary remediation challenges is the removal of residual complex organic compounds present in the OSPW. In the present study, the molecular constitution of OSPW from aerated and nonaerated wetland treatments were characterized in constructed wetland treatment systems. Negative-ion and positive-ion atmospheric pressure photoionization (APPI) Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR-MS) was used to provide extensive molecular-level analysis of the samples. Multiple aerated and nonaerated treatment wetland systems were characterized in terms of naphthenic acids (NAs), oxy-NAs, heteroatom NAs class, and double bond equivalent (DBE) versus carbon number to evaluate their molecular composition and variability. A broad range of heteroatom compound classes with variable relative abundances were identified. The DBE versus carbon number analysis revealed different levels of transformation of the compound classes, an indicator of NA fraction compound susceptibility to transformation. The selectivity and the extent of transformation of the compound classes were a function of the wetland design. The complementarity in the heteroatom classes detected in negative-ion and positive-ion APPI FT-ICR-MS highlight the need for multiple ionization methods for more complete coverage of the distribution of components in OSPW. The detailed molecular-level information can be useful for prediction of the fate and associated toxicity of the species and also treatment efficiencies of the wetland systems.

Al-Khafaji, A., Wilson, M., Neville, A., Wen, D., 2019. Pore-scale displacement efficiency during different salinity water flooding in hydrophilic and hydrophobic microstructures. Energy & Fuels 33, 3859-3870.


Previous macroscopic core flooding tests have shown that injecting low-salinity water improves oil recovery in sandstone and carbonate reservoirs through wettability alteration. However, consistent mechanistic clarification of the underlying physicochemical mechanisms involved in oil wettability at the pore-scale level is not fully understood. In this work, a microfluidic approach is used to provide in

situ visualization of oil–brine flow to give an indication of the micromechanisms affecting oil sweep efficiency. The potential of enhancing oil recovery by low-salinity flooding at the microscale is also investigated, which would help in predicting a reservoir’s performance before committing to production processes at a large field scale. Two types of crude oils with various acid numbers were used, and hydrophilic and hydrophobic physical microstructures were used to mimic sandstones and carbonates. The results revealed a reduction by 7–10% in the residual oil for the water-wet microstructure when the seawater was diluted twice from its original concentration, apparently due to a decrease in the attractive forces. There is no change in the recovery factor for the oil-wet micromodel for the two kinds of crude oils examined. Tertiary low-salinity flooding did not show any effect on the initial wetting state of the hydrophobic surface, rendering it with a strongly oil-wet condition. It is also observed that flow dynamics of the two microstructures examined are different, as the snap-off–coalesce phenomenon dominants the flow in the water-wet system, while oil moved by a piston-like displacement with a stable or irregular front in the hydrophobic system. In contrast to some of the published macroscopic results, our pore-scale displacement shows that low-salinity flooding seems to be an unsuitable choice for enhanced oil recovery for strongly oil-wet reservoirs.

Al-Saad, H., Al-Khafaji, A.J., Sadooni, F.N., 2019. Evaluation of the source rock potential of the Unyazah Formation (late Carboniferous-Early Permian) in Dukhan Field, Qatar. Petroleum Science and Technology 37, 1655-1664.

https://doi.org/10.1080/10916466.2019.1602636

Twenty samples were collected from the Unayzah Formation in three wells from Dukhan Field, Qatar. Many samples were of poor quality due to the low TOC content containing gas prone-kerogen type III and IV. The Rock-Eval maturity parameters indicate that many samples were immature, while the mature samples generated dry gas. The C15+ extracts GC suggests a marine input, while they have kerogen type III and IV which are usually derived from terrestrial input. This may be due to the abundance of G. Prisca which was probably recycled from older sediments. The organic matter may also have been subjected to oxidation, leaching, biodegradation or recycling due to the changing nature of the depositional environment that ranged from braided river system to marine settings.

Al-Salem, S.M., 2019. Thermal pyrolysis of high density polyethylene (HDPE) in a novel fixed bed reactor system for the production of high value gasoline range hydrocarbons (HC). Process Safety and Environmental Protection 127, 171-179.


Pyrolysis is a promising thermolysis technique to recover valuable oils and light hydrocarbons (HC) with high yields from plastic solid waste (PSW). In this work, thermal pyrolysis of high density polyethylene (HDPE) with the aim of producing gasoline range hydrocarbon oils, has been carried out in a novel fixed bed (batch) reactor. The pyrolysis of HDPE has been conducted between 500 to 800 °C in the presence of nitrogen as an inert carrier gas media to produce liquid fuel oil, gaseous products and solid char. The optimum temperature of obtaining maximum oil product yield (70%) was 550 °C. A comprehensive gas chromatography (GC) analysis of the liquid and gaseous products was conducted to quantify high molecular weight individual HC components. Moreover, light molecular weight HC constituting the gaseous fraction were identified. A chemical kinetic analysis of the cracking reactions, was performed to investigate the reaction mechanism of yielding the maximum oil product. The oil product recovered had a high proportion of aliphatic HC especially in the range of C8 to C12, whilst aromatic HC were of lower proportion. The carbon number of the pyrolysis oil was noted to increase proportionally with the increasing operating temperature. The

gaseous product had a high percentage (> 70%) of C2 to C4 HC, which was attributed to the high activity of carbon/carbon (C-C) chain scission reaction.



Using nanoparticles into a drilling fluid (mud) is a promising technique that could solve a range of problems presently encountered during drilling operations. This paper reports the development of a novel drilling fluid using a biopolymer/nanoparticle mixture to improve the performance of a water-based mud (WBM) formulation, enhancing rheological, filtration and lubrication properties. The xanthan gum- SiO2 mixture developed is proposed as a solution to operating challenges in drilling operation, with the synergistic properties of nanoparticles and polymer offering desirable properties. The novel nanofluids characterised by scanning electron microscope, X-ray diffraction, Fourier transform infrared spectroscopy and thermal-gravimetric analysis. The modified drilling fluids were found to have higher yield point, beneficial for hole cleaning, showed less filtrate loss and more bit lubrication than conventional WBM formulations. Properly engineered, nanoparticles could improve the performance of presently deployed drilling fluids significantly.

Al Maskari, N.S., Sari, A., Saeedi, A., Xie, Q., 2019. Influence of surface roughness on the contact angle due to calcite dissolution in an oil–brine–calcite system: A nanoscale analysis using atomic force microscopy and geochemical modeling. Energy & Fuels 33, 4219-4224.


Low-salinity water flooding appears to be a promising means to improve oil recovery in carbonate reservoirs because of a wettability alteration process. Contact angle measurement is a direct approach to reveal the wettability alteration in an oil–brine–carbonate system. However, questions have been raised about using contact angle measurement to justify the wettability alteration. This is because the contact angle may be significantly affected by surface roughness variation in the presence of low-salinity water because of calcite dissolution during the contact angle measurement. To clarify the cause and effect of wettability alteration during low-salinity water flooding, we measured the contact angle on two calcite substrates with similar surface roughness (7 and 4 nm) in the presence of high-salinity water (1 mol NaCl + 0.01 mol CaCl2) and low-salinity water (100 times diluted high-salinity water). Moreover, we measured the surface roughness of the substrates before and after the contact angle measurements using atomic force microscopy (AFM). Furthermore, we performed a geochemical study to quantify the amount of calcite dissolution in the presence of low- and high-salinity brines and compared it with surface roughness measurements. Our contact angle and AFM results reveal that surface roughness increase due to calcite dissolution in low-salinity water plays a negligible role in the contact angle, rather confirming that oil–brine–rock interactions govern the system wettability. Furthermore, our geochemical study shows that low-salinity water only dissolves 1.16 × 10–4 mol/mol of calcites in low-salinity water during the contact angle measurement. We, therefore, eradicate the possibility that surface roughness variation due to calcite dissolution in low-salinity water would affect contact angle results. Consequently, we argue that contact angle measurement remains a valid approach to directly examine the wettability alteration process in low-salinity water flooding.

Alberti, M., Arabas, A., Fürsich, F.T., Andersen, N., Ziółkowski, P., 2019. The Middle to Upper Jurassic stable isotope record of Madagascar: Linking temperature changes with plate tectonics during the break-up of Gondwana. Gondwana Research 73, 1-15.

http://www.sciencedirect.com/science/article/pii/S1342937X1930098X

Stable isotope (δ18O, δ13C) analyses were performed on well preserved belemnites, oysters, and rhynchonellid brachiopods from the Middle to Upper Jurassic of the Morondava Basin in southern Madagascar. Both brachiopods and oysters indicate similar average temperatures of 18.7 to 19.3 °C in the Early Callovian, followed by a temperature decrease towards the Middle Oxfordian (13.9 °C) and a minimum in the Early Kimmeridgian (12.3 °C). In contrast, belemnites from the Oxfordian show lower average temperatures of 10.0 °C, which is likely caused by specific conditions for these organisms (e.g., different fractionation or life habits). Additionally, three oysters from the Upper Oxfordian and Lower Kimmeridgian were used for high-resolution stable isotope analyses. The data show seasonal fluctuations of >6 °C around averages between 14.4 and 14.7 °C. Latitudinal temperature gradients for the Callovian and Kimmeridgian are similar to today at the examined low latitudes of the southern hemisphere. The observed cooling of around 5 °C from the Callovian to the Oxfordian/Kimmeridgian can be attributed to a concurrent southward drift of Madagascar during the break-up of Gondwana. Thus, the study underlines the importance of considering palaeogeography in interpreting stable isotope data as well as the potential of detecting and timing palaeogeographic events by using stable isotope analyses.

Aldousary, S., Kovscek, A.R., 2019. The diffusion of water through oil contributes to spontaneous emulsification during low salinity waterflooding. Journal of Petroleum Science and Engineering 179, 606-614.


Increases in oil recovery due to Low Salinity Waterfloods (LSW) have been widely investigated. Literature is abundant with studies attempting to pinpoint the relevant mechanisms involved in the LSW process. Recently, there was clear evidence of spontaneous formation of emulsions during LSW under certain conditions. This work examines the diffusion of water through oil as a contributing factor for spontaneous emulsification during LSW. Experimental observations are pore scale using etched-silicon micromodels. Observations are accompanied by pore-scale mass transfer calculations. Spontaneous emulsification is observed as a result of so-called “low salinity water” and crude oil phases contacting under non-equilibrium conditions. The experimental observations provide clear evidence that physical contact between oil and low salinity water phases is imperative for emulsification. In addition, it is concluded that a larger salinity gradient results in greater emulsion concentrations. In such cases, the crude oil is preequilibrated through exposure to a formation brine that has substantial salinity and divalent cations. Emulsification results as the oil phase comes into equilibrium with a brine of lower salinity and different composition. A key mechanism is the osmotic pressure imbalance between water and oil phases that drives water into the oil phase by diffusion. Water reaches a supersaturated state and spontaneous nucleation of the water phase results in emulsions, under appropriate conditions. The experimental and numerical modeling schemes presented here demonstrate and quantify time scales of water-in-oil emulsion formation.

Alekseyev, V.A., 2019. Nanoparticles and nanofluids in water–rock interactions. Geochemistry International 57, 357-368.

https://doi.org/10.1134/S0016702919040037

The paper presents a concise review of published information on nanogeochemistry, a new field of geochemistry that deals with particles and fluids of small size (<100 nm). The properties of these particles and fluids differ from those of their larger analogues because of the greater contributions of their surface energy. The paper discusses the conditions, forms, and mechanisms of their origin and evolution and presents examples illustrating how the properties of nanoparticles and nanofluids (their solubility and stability, melting temperature, inner pressure, surface charge and adsorption, evaporation rate, and chemical reactions and transport) depend on their size. It is demonstrated that concave and convex surfaces differently affect theses properties. Nanoparticles and nanofluids are widespread in nature and can thus affect various geochemical processes. Nanoparticles can adsorb heavy metals and are the dominant mode of their transport in natural waters. Nanofluids (nanopores) control processes of diagenesis, metasomatic replacement, weathering, and gas migration in shales. Even if contained in minor concentrations, nanoparticles can principally change the behavior of macrosystems. The paper presents a review of the main research avenues pursued by nanogeochemistry.

Alhesan, J.S.A., Marshall, M., Jackson, W.R., Qi, Y., Cassidy, P.J., Chaffee, A.L., 2019. Isolation of organic matter by the NaOH-HCl method from two marine oil shales using oven and sealed autoclave techniques. Oil Shale 3, 197-213.

https://doi.org/10.3176/oil.2019.2S.10

Organic matter (OM) was isolated from two marine oil shales, El-Lajjun and Julia Creek, using NaOH-HCl and humin and humic acid fractions separated. Two treatments were required to reduce humin ash yield to below 11 wt% db. The humin yield of the autoclave method was 80 wt% of OM (dry mineral-matter-free, dmmf), compared to only 20–60 wt% dmmf for the oven method, possibly due to the increased NaOH solution strength and some oxidation. Oven and autoclave methods both gave humin similar in chemical structure to shale OM, regardless of yield. This similarity has implications as to shale OM structure.



Dibenzofuran (DBF) derivatives have caused serious environmental problems, especially those produced by paper pulp bleaching and incineration processes. Prominent for its resilient mutagenicity and toxicity, DBF poses a major challenge to human health. In the present study, a new strain of Pseudomonas aeruginosa, FA-HZ1, with high DBF-degrading activity was isolated and identified. The determined optimum conditions for cell growth of strain FA-HZ1 were a temperature of 30 °C, pH 5.0, rotation rate of 200 rpm and 0.1 mM DBF as a carbon source. The biochemical and physiological features as well as usage of different carbon sources by FA-HZ1 were studied. The new strain was positive for arginine double hydrolase, gelatinase and citric acid, while it was negative for urease and lysine decarboxylase. It could utilize citric acid as its sole carbon source, but was negative for indole and H2S production. Intermediates of DBF 1,2-dihydroxy-1,2-dihydrodibenzofuran, 1,2-dihydroxydibenzofuran, 2-hydroxy-4-(3′-oxo-3′H-benzofuran-2′-yliden)but-2-enoic acid, 2,3-dihydroxybenzofuran, 2-oxo-2-(2′-hydrophenyl)lactic acid, and 2-hydroxy-2-(2′-hydroxyphenyl)acetic acid were detected and identified through liquid chromatography-mass analyses. FA-HZ1 metabolizes DBF by both the angular and lateral dioxygenation pathways. The genomic study identified 158 genes that were involved in the catabolism of aromatic compounds. To

identify the key genes responsible for DBF degradation, a proteomic study was performed. A total of 1459 proteins were identified in strain FA-HZ1, of which 100 were up-regulated and 104 were down-regulated. A novel enzyme “HZ6359 dioxygenase”, was amplified and expressed in pET-28a in E. coli BL21(DE3). The recombinant plasmid was successfully constructed, and was used for further experiments to verify its function. In addition, the strain FA-HZ1 can also degrade halogenated analogues such as 2, 8-dibromo dibenzofuran and 4-(4-bromophenyl) dibenzofuran. Undoubtedly, the isolation and characterization of new strain and the designed pathways is significant, as it could lead to the development of cost-effective and alternative remediation strategies. The degradation pathway of DBF by P. aeruginosa FA-HZ1 is a promising tool of biotechnological and environmental significance.

Alimohammadi, S., Zendehboudi, S., James, L., 2019. A comprehensive review of asphaltene deposition in petroleum reservoirs: Theory, challenges, and tips. Fuel 252, 753-791.


Asphaltene is the heaviest and most polar fraction of crude oils, which is usually defined as a solubility class, soluble in light aromatics, benzene and toluene, and insoluble in paraffins. Asphaltene precipitation/deposition negatively affects a variety of oil and gas processes, including oil recovery, transportation, and petroleum processing as it exhibits some undesirable impacts such as an increase in the viscosity of crudes and stability of the emulsions, a decrease in the distillate yields, and unstable phase separation. Experimental and theoretical investigations have revealed that asphaltene precipitation/deposition is influenced by several parameters/variables, including pressure, temperature, characteristics of the involved mixtures, properties and amount of precipitants, and characteristics of porous media. Knowing the undeniable consequences of asphaltene precipitation/deposition such as reduction of well productivity and/or blockage of the surface facilities, the effective treatments or inhibition techniques have gained widespread attention in the petroleum industry so far. Hence, a comprehensive knowledge of previous findings and an adequate understanding of different aspects of asphaltene precipitation/deposition (e.g., mechanisms and characterization) seem to be pivotal. Various attempts have been made to investigate different aspects of this phenomenon including thermodynamics of precipitation, kinetics of flocculation, and deposition mechanisms. The previous studies and importance of asphaltene in the oil and gas industry inspired us to provide a comprehensive review of the asphaltene precipitation/deposition that helps to further understand the governing mechanisms, thermodynamic behaviors, and transport phenomena prospects in this area. In this review work, the theories and mechanisms of precipitation/deposition, experimental and modelling approaches, the effects of operational parameters, and treatment/inhibition techniques are reviewed. Moreover, the economic analysis of flow assurance and the most common theoretical and practical challenges in asphaltene precipitation/deposition are studied.


http://www.sciencedirect.com/science/article/pii/S0025326X19303029

Mobile nuclear magnetic resonance (NMR) operating in Earth's magnetic field is adapted to detect leaked or spilled oil trapped in or under sea ice without the need to place any personnel on the ice. A helicopter placed a 6-meter diameter NMR coil system weighing approximately 1000 kg on 92 cm-thick ice surrogate and detected the equivalent of 1 cm thick oil under the ice surrogate in 3–1/2 min.

Amer, M.W., Aljariri Alhesan, J.S., Marshall, M., Awwad, A.M., Al-Ayed, O.S., 2019. Characterization of Jordanian oil shale and variation in oil properties with pyrolysis temperature. Journal of Analytical and Applied Pyrolysis 140, 219-226.


Marine oil shale from the Sultani mine was characterized (ultimate and proximate analysis, 13C NMR, differential thermogravimetry (DTG)). The 13C NMR indicated that the shale is highly aliphatic, and the concentration of carbonyl carbon is small. DTG indicated a total weight loss of 21 wt% to 550 °C. The shale was pyrolysed to different final temperatures in the range 360–540 °C under N2 and the shale oils produced characterized by utilization parameters (API, heating value, boiling point distribution) and by chemical properties (1H-NMR and gas chromatography-mass spectrometry GC–MS) as a function of final pyrolysis temperature. Previous studies have only investigated the utilization properties of marine-shale oil at one temperature. The average oil yield increased with pyrolysis temperature to a maximum at 520 °C, and then fell. The oil density was higher at 440–520 °C than at 360–400 °C (0.99–1.00, 0.96−0.97 g/cm3 respectively). Unexpectedly, oil heating value (39.7–40.0 MJ/kg in 360–540 °C) and sulfur content (11.25 wt% in 360–520 °C) were independent of pyrolysis temperature. Oil distillation indicated that up to 90 vol% was in the diesel fraction.

1H-NMR implied that the oil produced at all temperatures was highly aliphatic. GC/MS for the oil indicated the presence of long chain hydrocarbons (C11-C32), both normal and branched, some substituted benzenes, and high concentrations of sulfur compounds, mainly substituted thiophenes with same benzothiophenes. The average molecular weight of the sulfur compounds and proportion of heavier oil were higher at 520 °C than at 460 °C, so that the increased yield of oil at higher temperatures would have to be balanced against the lower quality of the crude shale oil produced. The results emphasized the importance of studying oil properties as a function of pyrolysis temperature, as differences which could be important in practice were noted.

Anderson, L.D., Bebout, G.E., Izawa, M.R.M., Bridge, N.J., Banerjee, N.R., 2019. Chemical alteration and preservation of sedimentary/organic nitrogen isotope signatures in a 2.7 Ga seafloor volcanic sequence. International Journal of Astrobiology 18, 235-250.

https://doi.org/10.1017/S1473550417000441

Massive to lobate volcanic flows and brecciated hyaloclastite units in the Abitibi greenstone belt allow investigation of Late Archæan seafloor alteration and associated incorporation into these rocks of nitrogen (N) biogeochemical signatures. In this suite (the Blake River Group), hyaloclastite units containing putative microbial ichnofossils are particularly enriched in large-ion lithophile elements (K, Rb, Ba, Cs), B, and Li, consistent with their having experienced the greatest fluid–rock interaction during subseafloor hydrothermal alteration. Similarly, silicate-δ18O and δ15N values for samples from the hyaloclastites show the greatest shifts from plausible magmatic values. The chemical and isotopic patterns in these tholeiitic igneous rocks greatly resemble those in modern altered seafloor basalts, consistent with the preservation of an Archæan seafloor alteration signature. The N enrichments and shifts in δ15N appear to reflect stabilization of illite and interaction with fluids carrying sedimentary/organic signatures. Enrichments of N (and the δ15N of this N) in altered glass volcanic rocks on Earth's modern and ancient seafloor point to the potential utility of N for tracing past and present biogeochemical processes in similar rocks at/near the Mars surface.



The sulfur-bearing limestones interbedded in the upper Miocene diatomaceous sediments (Tripoli Fm.) of the Lorca Basin (SE Spain) are typified, as other Mediterranean coeval carbonate and gypsum deposits, by filamentous, circular and rod-shaped microstructures of controversial origin. These features have been interpreted both as faecal pellets of brine shrimps and/or of copepods, remains of algae or cyanobacteria and fossilized sulfide-oxidizing bacteria. To shed light on their origin, a multidisciplinary study including optical, UV and scanning SEM electron microscopy, Raman microspectroscopy and geochemical (C carbon and O oxygen stable isotopes) analyses has been carried out on three carbonate beds exposed along the La Serrata ridge. The different composition of the filamentous and circular objects with respect to the rod-shaped microstructures suggest that the former represent remains of bacteria, while the latter faecal pellets of deposit- or suspension-feeder organisms. Size and shape of the filamentous and circular microfossils are consistent with their assignment to colorless sulfide-oxidizing bacteria like Beggiatoa (or Thioploca) and Thiomargarita, which is further supported by the presence, only within the microfossil body, of tiny pyrite grains. These grains possibly result from early diagenetic transformation of original sulfur globules stored by the bacteria, which are a diagnostic feature of this group of prokaryotes. The development of microbial communities dominated by putative sulfide-oxidizing bacteria at Lorca was caused favoured by hydrogen sulfide flows generated through degradation of organic matter by sulfate-reducing bacteria thriving in underlying organic-rich sediments.

Antunes, J., Leão, P., Vasconcelos, V., 2019. Marine biofilms: diversity of communities and of chemical cues. Environmental Microbiology Reports 11, 287-305.

https://doi.org/10.1111/1758-2229.12694

Surfaces immersed in seawater are rapidly colonized by various microorganisms, resulting in the formation of heterogenic marine biofilms. These communities are known to influence the settlement of algae spores and invertebrate larvae, triggering a succession of fouling events, with significant environmental and economic impacts. This review covers recent research regarding the differences in composition of biofilms isolated from different artificial surface types and the influence of environmental factors on their formation. One particular phenomenon – bacterial quorum sensing (QS) – allows bacteria to coordinate swarming, biofilm formation among other phenomena. Some other marine biofilm chemical cues are believed to modulate the settlement and the succession of macrofouling organisms, and they are also reviewed here. Finally, since the formation of a marine biofilm is considered to be an initial, QS‐dependent step in the development of marine fouling events, QS inhibition is discussed on its potential as a tool for antibiofouling control in marine settings.

Atkinson, J.W., Wignall, P.B., 2019. How quick was marine recovery after the end-Triassic mass extinction and what role did anoxia play? Palaeogeography, Palaeoclimatology, Palaeoecology 528, 99-119.


Oxygen restricted conditions were widespread in European shelf seas after the end-Triassic mass extinction event and they are reported to have hindered the recovery of marine benthos. Here we reconstruct the redox history of the Early Jurassic Blue Lias Formation of southwest Britain using pyrite framboid size analysis and compare this with the recovery of bivalves based on field and museum collections. Results suggest widespread dysoxia punctuated by periods of anoxia in the region, with the latter developing frequently in deeper water settings. Despite these harsh conditions, initial benthic recovery occurred rapidly in the British Jurassic, especially in shallowest settings, and shows no relationship with the intensity of dysoxia. A stable diversity was reached by the first recognised ammonite zone after the end-Triassic mass extinction. This contrasts with the deeper-water, more oxygen-poor sections where the diversity increase was still continuing in the earliest Sinemurian Stage, considerably longer than previously reported. Similar recovery rates are seen amongst other groups (brachiopods and ammonites). Oxygen-poor conditions have been suggested to delay recovery after the Permo-Triassic mass extinction, but this is not the case after the end-Triassic crisis. We suggest that this was because the European dysoxia was only a regional phenomenon and there were plenty of well-ventilated regions available to allow an untrammelled bounce back.

Atwah, I., Sweet, S., Pantano, J., Knap, A., 2019. Light hydrocarbon geochemistry: Insight into Mississippian crude oil sources from the Anadarko Basin, Oklahoma, USA. Geofluids 2019, Article 2795017.

https://doi.org/10.1155/2019/2795017

The Mississippian limestone is a prolific hydrocarbon play in the northern region of Oklahoma and the southern part of Kansas. The Mississippian reservoirs feature variations in produced fluid chemistry usually explained by different possible source rocks. Such chemical variations are regularly obtained from bulk, molecular, and isotopic characteristics. In this study, we present a new geochemical investigation of gasoline range hydrocarbons, biomarkers, phenols, and diamondoids in crude oils produced from Mississippian carbonate and Woodford Shale formations. A set of oil samples was examined for composition using high-performance gas-chromatography and mass-spectrometry techniques. The result shows a distinct geochemical fingerprint reflected in biomarkers such as the abundance of extended tricyclic terpanes, together with heptane star diagrams, and diamantane isomeric distributions. Such compounds are indicative of the organic matter sources and stages of thermal maturity. Phenolic compounds varied dramatically based on geographic location, with some oil samples being depleted of phenols, while others are intact. Based on crude oil compositions, two possible source rocks were identified including the Woodford Shale and Mississippian mudrocks, with a variable degree of mixing reported. Variations in phenol concentrations reflect reservoir fluid dynamic and water interactions, in which oils with intact phenols are least affected by water-washing conversely and crude oils depleted in phenols attributed to reservoir water-washing. These geochemical parameters shed light into petroleum migration within Devonian-Mississippian petroleum systems and mitigate geological risk in exploring and developing petroleum reservoirs.

Babu, N.R., Lin, P.-H., Abutaqiya, M.I.L., Sisco, C.J., Wang, J., Vargas, F.M., 2019. Systematic investigation of asphaltene deposition in the wellbore and near-wellbore region of a deepwater oil reservoir under gas injection. Part 2: Computational fluid dynamics modeling of asphaltene deposition. Energy & Fuels 33, 3645-3661.


Asphaltene deposition during oil production is a major flow assurance problem. The asphaltene deposit layer reduces the pipe cross-section, leading to a significant reduction in the flow rate and eventually plugging the pipeline. This flow assurance problem caused during oil production has motivated the development of several experimental and modeling techniques to investigate the asphaltene behavior. This study proposes an integrated approach to simultaneously model asphaltene precipitation, aggregation, and deposition on a single platform. It focuses on the development of a deposition simulator that performs thermodynamic modeling using the perturbed chain version of the statistical associating fluid theory equation of state (PC-SAFT EOS) and depicts the deposition profile by means of a computational fluid dynamics (CFD) model based on the finite element method. In this work, the asphaltene deposition risk was assessed in the near-wellbore region and the production tubing as a result of gas breakthrough. To achieve this goal, a sample of crude C2 was analyzed to determine its properties and also the tendency of the asphaltenes contained in this sample to precipitate and deposit under various conditions. Laboratory-scale experiments were performed to analyze the rates of asphaltene precipitation, aggregation, and deposition. With the results obtained from the various experiments, advanced modeling methods based on PC-SAFT EOS and CFD models were calibrated and used to predict asphaltene precipitation and deposition under field conditions. Simulation methods for oil flow and asphaltene precipitation in the near-wellbore region of the reservoir and inside the production tubing were coupled to provide the most rigorous modeling approach ever developed to understand and predict this complex flow assurance problem. The results show a low to moderate asphaltene deposition rate produced by crude C2 as the gas breaks through. Nevertheless, further investigation is recommended to analyze the effect of other fluids that may be co-produced to enhance our ability to understand and predict asphaltene deposition under different conditions.

Bagherinia, R., Assareh, M., Feyzi, F., 2019. Thermodynamic modelling of wax precipitation using PC-SAFT in a multi-solid framework. International Journal of Oil, Gas and Coal Technology 21, 229-249.

https://www.inderscience.com/info/inarticle.php?artid=99590

In this work, a multi-solid approach is used for wax precipitation modelling with PC-SAFT. A vapour/liquid/solids calculation is performed for determination of wax precipitation weight percent. Beside this, the proposed model is applied to predict the wax appearance temperature (WAT) for the published oil samples experimental precipitation data. The PC-SAFT parameters for petroleum plus fractions are estimated with reliable correlations. Finally, the results of modelling are compared with the results of Lira-Galeana et al. (1996), Pedersen et al. (1991), Dalirsefat and Feyzi (2007) models and a recent work of the authors using a solid solution approach with PC-SAFT plus UNIQUAC activity coefficients according to Bagherinia et al. (2016). The results demonstrate progress in accuracy and propose the model as an acceptable predictive tool. The average absolute deviations percent for WAT estimation over all fluid samples is 0.2, in comparison with 0.55 for the recently published modelling approach (Bagherinia et al., 2016).

Baines, K.H., Sromovsky, L.A., Carlson, R.W., Momary, T.W., Fry, P.M., 2019. The visual spectrum of Jupiter's Great Red Spot accurately modeled with aerosols produced by photolyzed ammonia reacting with acetylene. Icarus 330, 217-229.


We report results incorporating the optical properties of the red-tinted photochemically-generated aerosols of Carlson et al. (2016, Icarus 274, 106–115) in spectral models of Jupiter's Great Red Spot

(GRS). This material - created in laboratory GRS simulations from acetylene reacting with photolytic products of ammonia produced by ~0.2-μm radiation, similar to solar radiation on Jupiter within and above the upper troposphere, provides an excellent match to 0.35–1.05-μm spectra of the core of the Great Red Spot obtained by the Visual Infrared Mapping Spectrometer (VIMS) during the 2000–2001 Cassini-Huygens flyby. Radiative transfer models of GRS spectra acquired near the central-meridian (CM) and limb by the visual channel of the Cassini/VIMS near closest approach on December 31, 2000 and January 2, 2001, respectively, show remarkable agreement for model morphologies where the following conditions all exist: (1) most of the optical depth of the Carlson et al. (2016) chromophore resides near the top or above the main cloud layer, rather than being uniformly distributed within it, (2) the chromophore consists of relatively small particles in the 0.1–0.2 μm range, and (3) the 1-μm optical depth of the chromophore layer is small, of the order of 0.1–0.2. For such models, the chromophore layer mass abundance is 32–40 μgm cm−2. Consideration of the availability of the acetylene and ammonia parent gas material near the observed chromophore layers gives powerful support for the chromophore residing at the top of the main cloud in the upper troposphere rather than residing as a detached layer in the stratosphere. Under steady-state formation/loss conditions, consideration of plausible eddy diffusion coefficients pertaining to the relatively quiescent Jovian upper atmosphere yield untenable vertical transport times of more than several centuries required to supply the acetylene needed to form the chromophore layer, with stratospheric chromophore models requiring more than half a millennium. Consideration of the convective nature of the GRS and possible presence of acetylene-generating thunderstorms yields upper-troposphere chromophore layer formation times ranging from 11 years to 1.5 months for (1) plausible eddy diffusion coefficients ranging from 104 to 106 cm2 s−1 and (2) efficient conversion of C2H2 and NH3 into the Carlson et al. (2016) chromophore. Thus, the enhanced red coloring of the GRS may be due to the combined effects of (1) the relatively high, 0.2-bar cloudtop where ammonia ice and gas are delivered to prime photo-dissociation altitudes, by (2) powerful convection, which also delivers acetylene from depth created by (3) lightning, which is itself a by-product and indicator of powerful convection, and aided by (4) the vortex nature of the GRS, which helps to confine and concentrate the chromophore as it forms over time within the GRS anticyclone.

Baird, M.A., Shliaha, P.V., Anderson, G.A., Moskovets, E., Laiko, V., Makarov, A.A., Jensen, O.N., Shvartsburg, A.A., 2019. High-resolution differential ion mobility separations/Orbitrap mass spectrometry without buffer gas limitations. Analytical Chemistry 91, 6918-6925.


Strong orthogonality between differential ion mobility spectrometry (FAIMS) and mass spectrometry (MS) makes their hybrid a powerful approach to separate isomers and isobars. Harnessing that power depends on high resolution in both dimensions. The ultimate mass resolution and accuracy are delivered by Fourier Transform MS increasingly realized in Orbitrap MS, whereas FAIMS resolution is generally maximized by buffers rich in He or H2 that elevate ion mobility and lead to prominent non-Blanc effects. However, turbomolecular pumps have lower efficiency for light gas molecules and their flow from the FAIMS stage complicates maintaining the ultrahigh vacuum (UHV) needed for Orbitrap operation. Here we address this challenge via two hardware modifications: (i) a differential pumping step between FAIMS and MS stages and (ii) reconfiguration of vacuum lines to isolate pumping of the high vacuum (HV) region. Either greatly ameliorates the pressure increases upon He or H2 aspiration. This development enables free optimization of FAIMS carrier gas without concerns about MS performance, maximizing the utility and flexibility of FAIMS/MS platforms.

Bâldea, I., 2019. Long carbon-based chains of interstellar medium can have a triplet ground state. Why is this important for astrochemistry? ACS Earth and Space Chemistry 3, 863-872.

https://doi.org/10.1021/acsearthspacechem.9b00008

The identification of linear carbon chain molecules in the interstellar medium (ISM) requires the correct assignment of their most stable isomers. Recent theoretical work on linear carbons done in the astrophysics/astronomy community claimed that out of the classes of linear carbon chains astronomically observed, all carbon-based chains with an even number of electrons possess singlet ground electronic states. Contrary to this view, we report here detailed DFT and CCSD(T) theoretical results demonstrating that the most stable isomer of the linear HC10N molecule is a triplet. Our study suggests that with a proper assignment of the electronic ground state, HC10N can still be identified in astronomical data, similar to the adjacent members HC9N and HC11N of the homologous HCnN series, which have long been reported in extraterrestrial media. The results presented in this paper are useful both for astrochemistry and for the general chemical science. The presently reported CCSD(T)-based values of the ionization and electron attachment energies can help further astrochemical modeling of the ISM. From a more general perspective, the results of this paper are interesting also because they provide important insight into the relationship between bond lengths and bond orders. We show that this relationship can be quantitatively described by means a simple analytic formula, which represents a modification of that proposed empirically by Pauling.

Ball, R., Brindley, J., 2019. The power without the glory: Multiple roles of hydrogen peroxide in mediating the origin of life. Astrobiology 19, 675-684.

https://www.liebertpub.com/doi/abs/10.1089/ast.2018.1886

The hydrogen peroxide (HP) crucible hypothesis proposed here holds that life began in a localized environment on Earth that was perfused with a flow of hydrogen peroxide from a sustained external source, which powered and mediated molecular evolution and the protocellular RNA world. In this article, we consolidate and review recent evidence, both circumstantial and tested in simulation in our work and in the laboratory in others' work, for its multiple roles in the evolution of the first living systems: (1) it provides a periodic power source as the thiosulfate–hydrogen peroxide (THP) redox oscillator, (2) it may act as an agent of molecular change and evolution and mediator of homochirality, and (3) the THP oscillator, subject to Brownian input perturbations, produces a weighted distribution of output thermal fluctuations that favor polymerization and chemical diversification over chemical degradation and simplification. The hypothesis can help to clarify the hero and villain roles of hydrogen peroxide in cell function, and on the singularity of life: of necessity, life evolved early an armory of catalases, the continuing, and all-pervasive presence of which prevents hydrogen peroxide from accumulating anywhere in sufficient quantities to host a second origin. The HP crucible hypothesis is radical, but based on well-known chemistry and physics, it is eminently testable in the laboratory, and many of our simulations provide recipes for such experiments.

Balter, V., Martin, J.E., Tacail, T., Suan, G., Renaud, S., Girard, C., 2019. Calcium stable isotopes place Devonian conodonts as first level consumers. Geochemical Perspectives Letters 10, 36–39.

https://www.geochemicalperspectivesletters.org/article1912

Conodont animals are an extinct group of jawless vertebrates whose hard parts, also known as conodont elements, represent the earliest evidence of a mineralised skeleton in the vertebrate lineage. Conodont elements are interpreted as parts of a feeding apparatus, which together with the presence of eyes and microwear patterns, support the controversial hypothesis that conodont animals were macrophagous predators and/or scavengers. Here, we explore the trophic position of five conodont

genera (Palmatolepis, Polygnathus, Ancyrodella, Ancyrognathus and Icriodus) from five contemporary Late Devonian sites distributed worldwide (France, Morocco, Vietnam and Australia) by means of calcium (Ca) stable isotope compositions. The seawater Ca isotope composition was calibrated using contemporary Late Devonian brachiopod isotopic values. By comparison with extant marine trophic chain composed of cartilaginous fish, conodont Ca isotope compositions are indicative of a zooplanktivore - primary piscivore niche, with no genus-specific trophic pattern. The question of active predation or scavenging cannot be resolved definitively but our results strongly suggest that Late Devonian conodonts were first level consumers

Barbato, M., Mapelli, F., Crotti, E., Daffonchio, D., Borin, S., 2019. Cultivable hydrocarbon degrading bacteria have low phylogenetic diversity but highly versatile functional potential. International Biodeterioration & Biodegradation 142, 43-51.


Hydrocarbon (HC) pollution is a threat to the marine environment and bioremediation strategies based on microbial degradation have been developed for pollution clean-up. Effectiveness of bioaugmentation, i.e. the addition of suitable HC-degrading microorganisms to the polluted matrix, strongly depends on the metabolic and physiological versatility of cultivable HC-degrading microorganisms and on their adaptation capacity. The aim of this work was to investigate the potential of laboratory enrichment approaches to obtain cultivable HC-degrading bacteria having versatility breadth. Despite we used as inoculum marine samples of different origin and contamination history, and applied different enrichment strategies, we brought into culture 183 hydrocarbonoclastic bacterial strains strongly dominated by only the two genera Alcanivorax and Marinobacter. These isolates, screened for traits related to HC degradation, biostimulation and abiotic stress tolerance, demonstrated nevertheless to have a diverse functional potential, correlated to the adopted enrichment strategy. Although the obtained strains resulted phylogenetically similar, we showed that multiple cultivation approaches enhanced their metabolic diversification with potential benefits for bioaugmentation effectiveness.

Barkley, Z.R., Lauvaux, T., Davis, K.J., Deng, A., Fried, A., Weibring, P., Richter, D., Walega, J.G., DiGangi, J., Ehrman, S.H., Ren, X., Dickerson, R.R., 2019. Estimating methane emissions from underground coal and natural gas production in southwestern Pennsylvania. Geophysical Research Letters 46, 4531-4540.

https://doi.org/10.1029/2019GL082131

Production of coal and natural gas is responsible for one third of anthropogenic methane (CH4) emissions in the United States. Here we examine CH4 emissions from coal and natural gas production in southwestern Pennsylvania. Using a top-down methodology combining measurements of CH4 and ethane, we conclude that while Environmental Protection Agency inventories appear to report emissions from coal accurately, emissions from unconventional natural gas are underreported in the region by a factor of 5 (±3). However, production-scaled CH4 emissions from unconventional gas production in the Marcellus remain small compared to other basins due to its large production per well. After normalizing emissions by energy produced, total greenhouse gas emissions from Pennsylvania unconventional natural gas production produce half the carbon footprint compared to regionally produced coal, with carbon dioxide emissions from combustion being the dominant source of greenhouse gas emissions for both sources.

Barnet, J.S.K., Littler, K., Westerhold, T., Kroon, D., Leng, M.J., Bailey, I., Röhl, U., Zachos, J.C., 2019. A high-fidelity benthic stable isotope record of Late Cretaceous–Early Eocene climate change and carbon-cycling. Paleoceanography and Paleoclimatology 34, 672-691.

https://doi.org/10.1029/2019PA003556

The Late Cretaceous–Early Paleogene is the most recent period in Earth history that experienced sustained global greenhouse warmth on multimillion year timescales. Yet, knowledge of ambient climate conditions and the complex interplay between various forcing mechanisms are still poorly constrained. Here we present a 14.75 million‐year‐long, high‐resolution, orbitally tuned record of paired climate change and carbon‐cycling for this enigmatic period (~67–52 Ma), which we compare to an up‐to‐date compilation of atmospheric pCO2 records. Our climate and carbon‐cycling records, which are the highest resolution stratigraphically complete records to be constructed from a single marine site in the Atlantic Ocean, feature all major transient warming events (termed “hyperthermals”) known from this time period. We identify eccentricity as the dominant pacemaker of climate and the carbon cycle throughout the Late Maastrichtian to Early Eocene, through the modulation of precession. On average, changes in the carbon cycle lagged changes in climate by ~23,000 years at the long eccentricity (405,000‐year) band, and by ~3,000–4,500 years at the short eccentricity (100,000‐year) band, suggesting that light carbon was released as a positive feedback to warming induced by orbital forcing. Our new record places all known hyperthermals of the Late Maastrichtian–Early Eocene into temporal context with regards to evolving ambient climate of the time. We constrain potential carbon cycle influences of Large Igneous Province volcanism associated with the Deccan Traps and North Atlantic Igneous Province, as well as the sensitivity of climate and the carbon‐cycle to the 2.4 million‐year‐long eccentricity cycle.

Becker, J.W., Hogle, S.L., Rosendo, K., Chisholm, S.W., 2019. Co-culture and biogeography of Prochlorococcus and SAR11. The ISME Journal 13, 1506-1519.

https://doi.org/10.1038/s41396-019-0365-4

Prochlorococcus and SAR11 are among the smallest and most abundant organisms on Earth. With a combined global population of about 2.7 × 1028 cells, they numerically dominate bacterioplankton communities in oligotrophic ocean gyres and yet they have never been grown together in vitro. Here we describe co-cultures of Prochlorococcus and SAR11 isolates representing both high- and low-light adapted clades. We examined: (1) the influence of Prochlorococcus on the growth of SAR11 and vice-versa, (2) whether Prochlorococcus can meet specific nutrient requirements of SAR11, and (3) how co-culture dynamics vary when Prochlorococcus is grown with SAR11 compared with sympatric copiotrophic bacteria. SAR11 grew 15–70% faster in co-culture with Prochlorococcus, while the growth of the latter was unaffected. When Prochlorococcus populations entered stationary phase, this commensal relationship rapidly became amensal, as SAR11 abundances decreased dramatically. In parallel experiments with copiotrophic bacteria; however, the heterotrophic partner increased in abundance as Prochlorococcus densities leveled off. The presence of Prochlorococcus was able to meet SAR11’s central requirement for organic carbon, but not reduced sulfur. Prochlorococcus strain MIT9313, but not MED4, could meet the unique glycine requirement of SAR11, which could be due to the production and release of glycine betaine by MIT9313, as supported by comparative genomic evidence. Our findings also suggest, but do not confirm, that Prochlorococcus MIT9313 may compete with SAR11 for the uptake of 3-dimethylsulfoniopropionate (DMSP). To give our results an ecological context, we assessed the relative contribution of Prochlorococcus and SAR11 genome equivalents to those of identifiable bacteria and archaea in over 800 marine metagenomes. At many locations, more than half of the identifiable genome equivalents

in the euphotic zone belonged to Prochlorococcus and SAR11 – highlighting the biogeochemical potential of these two groups.



Dams and wastewater may greatly perturb riverine fluxes of dissolved organic matter (DOM) and CO2, yet little is known about the relationships between altered DOM quality and CO2 emission in eutrophic impounded river systems. A basin-wide field survey of surface water CO2 and dissolved organic carbon (DOC) was combined with laboratory incubations to examine how dams and urban tributaries delivering treated wastewater influence longitudinal patterns in DOM properties and CO2 along the impounded Han River traversing Seoul metropolitan area. Fluorescent DOM indices including parallel factor analysis (PARAFAC) components were used to characterize DOM in relation to biodegradable DOC (BDOC). Compared with distinct downstream increases in DOC and CO2, BDOC concentration and its proportion in DOC (%BDOC) were highly variable along the mainstem and peaked at urban tributaries. Longitudinal increases in fluorescence index (FI), biological index (BIX), and two PARAFAC components (C2 and C3) contrasted with general decreases in humification index (HIX) and C1, reflecting increasing downstream inputs of anthropogenic DOM. During a 5-day incubation employing continuous CO2 measurements, the cumulative production of CO2 in the mainstem water mixed with urban tributary water was significantly higher than the level expected for conservative mixing of the two samples, indicating a synergistic enhancement of DOM biodegradation. Molecular formulas identified by Fourier transform-ion cyclotron resonance-mass spectrometry (FT-ICR-MS) revealed more consumed molecules in the mainstem water and more newly produced molecules in the tributary water over the 5-day incubation, implying abundant labile components in the mainstem water discharged from the upstream dam and highly processed tributary DOM limited in immediately biodegradable organic materials. Downstream increases in CO2 and DOC along the Han River, combined with the synergistic effect observed in the mixed water, suggest that mixing wastewater-derived DOM with labile autochthonous DOM can enhance CO2 production in the river system perturbed by impoundment and wastewater.

Beirão, J., Baillon, L., Litt, M.A., Langlois, V.S., Purchase, C.F., 2019. Impact of crude oil and the dispersant Corexit™ EC9500A on capelin (Mallotus villosus) embryo development. Marine Environmental Research 147, 90-100.


Marine food webs are particularly vulnerable to oil spills if keystone species are impacted. To quantify lethal and sublethal toxicity in a key Holarctic forage fish, capelin embryos were exposed to Hibernia crude oil water accommodated fraction (WAF) produced at an oil-to-water ratio of 1:9 (v:v) and chemically-enhanced WAF (CEWAF) produced with the dispersant Corexit™ EC9500A at a dispersant-to-oil ratio of 1:10 (CEWAF H) or 1:50 (CEWAF L). Corexit alone yielded similar embryotoxicity to CEWAF. 10% CEWAF H, with total polycyclic aromatic hydrocarbons of 99.2 μg/L, decreased embryo survival following 10 h of exposure, while continual exposed to 1% CEWAF L decreased hatching and heart rates. Concentrations down to 0.1% CEWAF L increased in a dose-dependent manner the transcript level of cytochrome P4501a1 (cyp1a1) in hatched larvae.

These data indicate that embryo-larval survival of capelin is likely at risk if an oil spill coincides in space and time with spawning.

Belle, S., Parent, C., 2019. Reconstruction of past dynamics of methane-oxidizing bacteria in lake sediments using a quantitative PCR method: Connecting past environmental changes and microbial community. Geomicrobiology Journal 36, 570-579.

https://doi.org/10.1080/01490451.2019.1583698

In this study, a quantitative PCR (qPCR) method was applied to amplify ancient DNA (aDNA) of different methane-oxidizing bacteria (MOB) types in lake sediments and to reconstruct microbial community dynamics over the last 1200 years. We also used reconstructions of in-lake nutrients concentrations, air temperature fluctuations, and sedimentary organic matter dynamics to study impacts of past environmental and climatic changes on MOB community composition. DNA preservation in lake sediments is sufficient, and qPCR amplification was successfully applied to the analysis of MOB aDNA. Temporal changes in MOB community showed different patterns between lakes, and drivers of past MOB dynamics slightly differed between lakes and among MOB groups. Overall, MOB developments were generally correlated to proxies of organic matter quality/quantity and climate data. Moreover, our results could emphasize the importance of nutrients availability in structuring MOB community, and the higher ability of MOB type 2 to access nutrients under nitrogen/nutrients limited conditions. Therefore, our study provides an operational and time-effective method to reconstruct past CH4 oxidation in lakes and could help to identify the driving factors of past temporal dynamics of MOB community.

Benna, M., Hurley, D.M., Stubbs, T.J., Mahaffy, P.R., Elphic, R.C., 2019. Lunar soil hydration constrained by exospheric water liberated by meteoroid impacts. Nature Geoscience 12, 333-338.

https://doi.org/10.1038/s41561-019-0345-3

Analyses of samples from the Apollo missions suggest that the Moon formed devoid of native water. However, recent observations by Cassini, Deep Impact, Lunar Prospector and Chandrayaan-1 indicate the existence of an active water cycle on the Moon. Here we report observations of this water cycle, specifically detections of near-surface water released into the lunar exosphere by the Neutral Mass Spectrometer on the Lunar Atmosphere and Dust Environment Explorer. The timing of 29 water releases is associated with the Moon encountering known meteoroid streams. The intensities of these releases reflect the convoluted effects of the flux, velocity and impact location of the parent streams. We propose that four additional detected water releases represent the signature of previously undiscovered meteoroid streams. We show that water release from meteoroid impacts is indicative of a lunar surface that has a desiccated soil layer of several centimetres on top of uniformly hydrated soil. We infer that the Moon is currently in the process of losing water that was either delivered long ago or present at its formation.

Berg, J.S., Pjevac, P., Sommer, T., Buckner, C.R.T., Philippi, M., Hach, P.F., Liebeke, M., Holtappels, M., Danza, F., Tonolla, M., Sengupta, A., Schubert, C.J., Milucka, J., Kuypers, M.M.M., 2019. Dark aerobic sulfide oxidation by anoxygenic phototrophs in anoxic waters. Environmental Microbiology 21, 1611-1626.

https://doi.org/10.1111/1462-2920.14543

Anoxygenic phototrophic sulfide oxidation by green and purple sulfur bacteria (PSB) plays a key role in sulfide removal from anoxic shallow sediments and stratified waters. Although some PSB can also oxidize sulfide with nitrate and oxygen, little is known about the prevalence of this chemolithotrophic lifestyle in the environment. In this study, we investigated the role of these phototrophs in light‐independent sulfide removal in the chemocline of Lake Cadagno. Our temporally resolved, high‐resolution chemical profiles indicated that dark sulfide oxidation was coupled to high oxygen consumption rates of ~9 μM O2·h−1. Single‐cell analyses of lake water incubated with 13CO2 in the dark revealed that Chromatium okenii was to a large extent responsible for aerobic sulfide oxidation and it accounted for up to 40% of total dark carbon fixation. The genome of Chr. okenii reconstructed from the Lake Cadagno metagenome confirms its capacity for microaerophilic growth and provides further insights into its metabolic capabilities. Moreover, our genomic and single‐cell data indicated that other PSB grow microaerobically in these apparently anoxic waters. Altogether, our observations suggest that aerobic respiration may not only play an underappreciated role in anoxic environments but also that organisms typically considered strict anaerobes may be involved.



Some of the advantages of the simultaneous use of surfactants and nanoparticles in enhanced oil recovery (EOR) processes are the increase in the efficiency of injection fluid for sweeping, the reduction of adsorption of the surfactant onto the reservoir rock, the alteration of wettability, and the reduction of water/crude oil interfacial tension (IFT). However, a large amount of nanoparticles required in chemical EOR processes might limit their application. Therefore, the main objective of this work is to synthesize, characterize, and evaluate magnetic iron core–carbon shell nanoparticles that can be recovered and to study their impact on the reduction of surfactant adsorption on the porous media and oil recovery at reservoir conditions. The additional benefit of the proposed method is that these nanoparticles can be recovered and reused after the application because of their magnetic properties. The magnetic iron core–carbon shell nanoparticles were obtained following a new one-pot hydrothermal procedure and were carbonized at 900 °C using a teflon-lined autoclave. The core–shell nanoparticles were characterized using scanning electron microscopy, dynamic light scattering, N2 physisorption at −196 °C, X-ray diffraction, X-ray photoelectron spectroscopy (XPS), and magnetometry measurements. The magnetic iron core–carbon shell nanoparticles with an average particle size of 60 nm were obtained. The XPS spectrum corroborated that magnetic Fe(0) of the core was adequately coated with a carbon shell. The IFT was measured using a spinning drop tensiometer for a medium viscosity crude oil and a surfactant mixture. The minimum IFT reached was approximately 1 × 10–4 mN m–1 at a nanoparticle concentration of 100 mg L–1. At this concentration, the dynamic adsorption tests demonstrated that the nanoparticles reduce 33% the adsorption of the surfactant mixture in the porous media. The simultaneous effect of core–shell nanoparticles and the surfactant mixture was evaluated in a displacement test at reservoir conditions obtaining a final oil recovery of 98%.

Bhatia, S.K., Gurav, R., Choi, T.-R., Han, Y.H., Park, Y.-L., Jung, H.-R., Yang, S.-Y., Song, H.-S., Yang, Y.-H., 2019. A clean and green approach for odd chain fatty acids production in Rhodococcus sp. YHY01 by medium engineering. Bioresource Technology 286, 121383.


Odd chain fatty acids serve as anti-allergic, anti-inflammatory, and antifungal agents, and are useful for the production of biodiesel. Rhodococcus sp. YHY01 utilizes a wide range of carbon sources and accumulate lipids i.e. fructose (37% w/w dcw) glucose (56% w/w dcw), glycerol (50% w/w dcw), acetate (42% w/w dcw), butyrate (65% w/w dcw), lactate (56% w/w dcw), and propionate (62% w/w dcw). In this study, propionate was proved as the best carbon source and produced 69% odd chain fatty acids of total fatty acids, followed by glycerol (13% odd chain fatty acids of total fatty acids). A synthetic medium optimized with response surface design containing glycerol, propionate, and ammonium chloride (0.32%:0.76%:0.040% w/v) facilitated the production of total fatty acids 69% w/w of dcw, and odd chain fatty acids comprised 85% w/w of total fatty acids. Major odd chain fatty acids were in the order C17:0 > C15:0 > Cis-10-C17:1 > 10Me-C17:0 > C19:0 > Cis-10-C19:1.

Bi, R., Nasrabadi, H., 2019. Molecular simulation of the constant composition expansion experiment in shale multi-scale systems. Fluid Phase Equilibria 495, 59-68.


The phase behavior of hydrocarbons in shale reservoirs has garnered increasing attention in the petroleum industry. Significant differences in the phase behavior of petroleum fluids between conventional reservoirs and shale reservoirs have been observed. Because of the existence of nano-scale porous media in shale reservoirs, there are substantial surface fluid interactions that can lead to a heterogeneous distribution of molecules and an alteration of the fluid phase behavior. In this work, for the first time, we use molecular simulations to investigate the confinement effect on the phase behavior of reservoir fluids in a multi-scale (nano-scale + macro-scale) media. The model has a confined region that mimics the nano-scale porous media and a bulk region that represents the macro-scale porous media (macropores and fractures) in shale reservoirs. For the first time, we use the Gibbs ensemble Monte Carlo (GEMC) simulation at imposed pressures to simulate the constant composition expansion (CCE) experiment for multi-component hydrocarbon mixtures in a multi-scale porous media. Our results show that because of the confinement effect, the composition of the bulk and the confined regions differ significantly. In our molecular simulations, the composition of the lighter components in the bulk region increases, while heavier components are mainly trapped in the confined region. These changes in the composition cause a significant shift or disappearance of the saturation pressure in the bulk region of the multi-component multi-scale hydrocarbon systems.



An airborne high repetition rate laser-induced plasma was applied as a versatile ambient ionization source for mass-spectrometric determinations of polar and nonpolar analytes in solution. The laser plasma was sustained between a home-built pneumatic nebulizer and the inlet capillary of an Orbitrap mass spectrometer. To maintain stable conditions in the droplet-rich spray environment, the plasma was directly fed by the fundamental output (λ = 1064 nm) of a current state-of-the-art diode-pumped solid-state laser. Ionization by the laser-driven plasma resulted in signals of intact analyte ions of several chemical categories. The analyte ions were found to be fully desolvated since no further increase in ion signal was observed upon heating of the inlet capillary. Due to the electroneutrality of the plasma, both positive and negative analyte ions could be formed simultaneously without altering the operational parameters of the ion source. While, typically, polar analytes with pronounced gas phase basicities worked best, nonpolar and amphoteric compounds were also detected. The latter

were detected with lower ion signals and were prone to a certain degree of fragmentation induced during the ionization process. All the described attests the laser-induced microplasma by a good performance in terms of stability, robustness, sensitivity, and general applicability as a self-contained ion source for the liquid sample introduction.

Bihani, A., Daigle, H., 2019. On the role of spatially correlated heterogeneity in determining mudrock sealing capacity for CO2 sequestration. Marine and Petroleum Geology 106, 116-127.


Storing CO2 in depleted hydrocarbon reservoirs is a common practice world-wide. Mudrocks often serve as seals above these reservoirs due to their small pore throats and low permeability, but they can fail if the buoyant pressure of the trapped fluid overcomes the threshold pressure of the seal. Mudrocks are primarily made of silt-sized and clay-sized particles, and sufficiently high silt concentrations can create situations where the silt grains create a connected stress chain through the rock matrix, which preserves the large pore throats under compaction. This phenomenon, termed silt bridging, can reduce the threshold pressure of the mudrock, causing seal failure. We used grain-scale modeling to create computer-generated grain packs with and without the effect of gravity to understand the effects of deposition and compaction on the petrophysical properties like capillary pressure, tortuosity, permeability, capillary drainage curves, and spatial correlation of heterogeneities. We found that, when the fraction of silt-sized grains exceeded 40%, the percolation length (the length of the first path of the non-wetting fluid through a medium) and the tortuosity suddenly decreased. This was supported by the results from the throat size variograms, where the same type of correlations between throats were observed at greater lag distances, signifying increased intergranular distances. Our work provides an insight into the role of different grain sizes, concentrations and spatial distributions on the flow properties and sealing capacity of mudrocks.

Bijlsma, L., Berntssen, M.H.G., Merel, S., 2019. A refined nontarget workflow for the investigation of metabolites through the prioritization by in silico prediction tools. Analytical Chemistry 91, 6321-6328.


The application of nontargeted strategies based on high-resolution mass spectrometry (HRMS) directed toward the discovery of metabolites of known contaminants in fish is an interesting alternative to true nontarget screening. To reduce prolonged and costly laboratory experiments, recent advances in computing power have permitted the development of comprehensive knowledge-based software to predict the metabolic fate of chemicals. In addition, machine-based learning tools allow the prediction of chromatographic retention times (RT) or collision cross section (CCS) values when using ion mobility spectrometry (IMS). These tools can ease data evaluation and strengthen the confidence in the identification of compounds. The current work explores the capabilities of in silico prediction tools, refined by the use of RT and CCS prediction, to prioritize and facilitate nontarget liquid chromatography (LC)–IMS–HRMS data processing. The fate of the insecticide pirimiphos-methyl (PM) in farmed Atlantic salmon exposed to contaminated feed was used as a case study. The theoretical prediction of 60 potentially relevant biological PM metabolites permitted the prioritization of screening in different salmon tissues (liver, kidney, bile, muscle, and fat) of known and unknown PM metabolites. An average of 43 potential positives was found in the sample matrixes based on the accurate mass of protonated molecules (mass error ≤5 ppm). The application of different tolerance filters for RT (Δ ≤ 2 min) and CCS (Δ ≤ 6%) based on predicted values permitted us to reduce this number up to 66% of the features. Finally, five PM metabolites could be identified; two known

metabolites (2-DAMP and N-desethyl PM) were confirmed with a standard, whereas three previously unknown metabolites (2-DAMP glucuronide, didesethyl PM, and hydroxy-2-DAMP glucuronide) were tentatively identified in different matrixes, allowing the first proposition of a metabolic pathway in fish.

Blachowicz, A., Chiang, A.J., Elsaesser, A., Kalkum, M., Ehrenfreund, P., Stajich, J.E., Torok, T., Wang, C.C.C., Venkateswaran, K., 2019. Proteomic and metabolomic characteristics of extremophilic fungi under simulated Mars conditions. Frontiers in Microbiology 10, 1013. doi: 10.3389/fmicb.2019.01013.


Filamentous fungi have been associated with extreme habitats, including nuclear power plant accident sites and the International Space Station (ISS). Due to immense adaptation and phenotypic plasticity capacities, fungi may thrive in what seems like uninhabitable niches. This study is the first report of fungal survival after exposure of monolayers of conidia to simulated Mars conditions (SMC). Conidia of several Chernobyl nuclear accident-associated and ISS-isolated strains were tested for UV-C and SMC sensitivity, which resulted in strain-dependent survival. Strains surviving exposure to SMC for 30 min, ISSFT-021-30 and IMV 00236-30, were further characterized for proteomic and metabolomic changes. Differential expression of proteins involved in ribosome biogenesis, translation, and carbohydrate metabolic processes was observed. No outstanding metabolome alterations were revealed. Lastly, ISSFT-021-30 conidia re-exposed to UV-C exhibited enhanced UV-C resistance when compared to the conidia of unexposed ISSFT-021.

Blanco, E., Hodgson, D.J.M., Hermes, M., Besseling, R., Hunter, G.L., Chaikin, P.M., Cates, M.E., Van Damme, I., Poon, W.C.K., 2019. Conching chocolate is a prototypical transition from frictionally jammed solid to flowable suspension with maximal solid content. Proceedings of the National Academy of Sciences 116, 10303-10308.

https://doi.org/10.1073/pnas.1901858116

Significance: Chocolate conching is the process in which an inhomogeneous mixture of fat, sugar, and cocoa solids is transformed into a homogeneous flowing liquid. Despite the popularity of chocolate and the antiquity of the process, until now, there has been poor understanding of the physical mechanisms involved. Here, we show that two of the main roles of conching are the mechanical breakdown of aggregates and the reduction of interparticle friction through the addition of a dispersant. Intriguingly, the underlying physics we describe is related to the popular stunt of “running on cornstarch.”

Abstract: The mixing of a powder of 10- to 50-μm primary particles into a liquid to form a dispersion with the highest possible solid content is a common industrial operation. Building on recent advances in the rheology of such “granular dispersions,” we study a paradigmatic example of such powder incorporation: the conching of chocolate, in which a homogeneous, flowing suspension is prepared from an inhomogeneous mixture of particulates, triglyceride oil, and dispersants. Studying the rheology of a simplified formulation, we find that the input of mechanical energy and staged addition of surfactants combine to effect a considerable shift in the jamming volume fraction of the system, thus increasing the maximum flowable solid content. We discuss the possible microscopic origins of this shift, and suggest that chocolate conching exemplifies a ubiquitous class of powder–liquid mixing.

Blevins, M.S., Klein, D.R., Brodbelt, J.S., 2019. Localization of cyclopropane modifications in bacterial lipids via 213 nm ultraviolet photodissociation mass spectrometry. Analytical Chemistry 91, 6820-6828.


Subtle structural features in bacterial lipids such as unsaturation elements can have vast biological implications. Cyclopropane rings have been correlated with tolerance to a number of adverse conditions in bacterial phospholipids. They have also been shown to play a major role in Mycobacterium tuberculosis (M. tuberculosis or Mtb) pathogenesis as they occur in mycolic acids (MAs) in the mycobacterial cell. Traditional collisional activation methods allow elucidation of basic structural features of lipids but fail to reveal the presence and position of cyclopropane rings. Here, we employ 213 nm ultraviolet photodissociation mass spectrometry (UVPD-MS) for structural characterization of cyclopropane rings in bacterial phospholipids and MAs. Upon UVPD, dual cross-ring C–C cleavages on both sides of the cyclopropane ring are observed for cyclopropyl lipids, resulting in diagnostic pairs of fragment ions spaced 14 Da apart, thus enabling cyclopropane localization. These diagnostic pairs of ions corresponding to dual cross-ring cleavage are observed in both negative and positive ion modes and afford localization of multiple cyclopropane rings within a single lipid. This method was integrated with liquid chromatography (LC) for LC/UVPD-MS analysis of cyclopropyl glycerophospholipids in Escherichia coli (E. coli) and for analysis of MAs in Mycobacterium bovis (M. bovis) and M. tuberculosis lipid extracts.

Blount, B.A., Ellis, T., 2019. Construction of an Escherichia coli genome with fewer codons sets records. Nature 569, 492-494.

https://www.nature.com/articles/d41586-019-01584-x

The biggest synthetic genome so far has been made, with a smaller set of amino-acid-encoding codons than usual — raising the prospect of encoding proteins that contain unnatural amino-acid residues.

Over the past decade, decreases in the costs of chemically synthesizing DNA and improved methods for assembling DNA fragments have enabled researchers to scale up synthetic biology to the level of generating entire chromosomes and genomes. So far, synthetic DNA has been constructed with up to one million base pairs, notably a set of chromosomes from the yeast Saccharomyces cerevisiae and several versions of the genome of the bacterium Mycoplasma mycoides1,2. Now, writing in Nature, Fredens et al.3 report the completion of a 4-million-base-pair synthetic version of the Escherichia coli genome. This is a landmark in the emerging field of synthetic genomics, and finally applies the technology to the laboratory’s workhorse bacterium.

Synthetic genomics offers a new way of understanding the rules of life, while at the same time moving synthetic biology towards a future in which genomes can be written to design. The pioneers in the field — the researchers at the J. Craig Venter Institute in Rockville, Maryland — have used this method to better define the minimal set of genes required for a free-living cell. By adopting an approach that involves redesigning genome segments by computer, chemically synthesizing the fragments and then assembling them, these pioneers succeeded2 in reducing the size of the M. mycoides genome by around 50%. Doing the same with just genome-editing tools would be much more laborious, as past work with E. coli demonstrates: here, gene-deletion methods have removed, at best, only 15% of the genome4.

Fredens and colleagues used this reduced genome from E. coli as the template for a synthetic genome with another kind of minimization in mind — codon reduction. The genetic code has inherent redundancy: there are 64 codons (triplets of ‘letters’, or bases) to encode just 20 amino acids plus the ‘start’ and ‘stop’ points that mark the beginning and end of a stretch of protein-coding sequence. This redundancy means, for example, that there are six codons that encode the amino acid serine, and three possible stop codons. Through design, synthesis and assembly, Fredens et al.3 have been able to construct an E. coli genome that uses only 61 of the 64 available codons in its protein-coding sequences, replacing two serine codons and one stop codon with synonyms (codons that are ‘spelt’ differently but give the same instruction). Past work using genome-editing tools has already produced a synthetic E. coli that uses just 63 of the 64 codons, but this required only the stop codons with the sequence TAG (of which there were just 321 around the genome) to be changed to an alternative stop codon5. Reduction to 61 codons demanded that a whopping 18,214 codons be changed, necessitating a genome-synthesis approach.

Fredens and colleagues built their synthetic E. coli genome by using large-scale DNA-assembly and genome-integration methods that they had developed previously6 to probe the limits of codon changes in E. coli. In their approach (Fig. 1), DNA is computationally designed, chemically synthesized and assembled in 100-kilobase fragments in vectors in S. cerevisiae; these vectors are then taken up by E. coli and integrated into the genome in the direct place of the equivalent natural region. Iterating this process five times resulted in 500-kilobase sections of DNA being replaced by synthetic versions. Eight strains of E. coli were produced in this way, each harbouring synthetic DNA sections that covered a different region of the genome. These sections were then combined using conjugation methods to make the complete synthetic genome.

The large-scale construction was impressively successful, with very low off-target mutation rates, but was not without its challenges. Many genes in the E. coli genome partially overlap with others, and in 91 cases the overlapping regions contained codons that needed to be changed. This is complex because synonymous alterations in one protein-coding sequence might alter the amino acids encoded by the overlapping one. To tackle this, the team ‘refactored’ 79 locations in the genome, duplicating the sequence to separate out overlapped coding sequences into individual recoded ones (Fig. 1). Although this approach was generally successful, it did require careful debugging in a few cases in which refactoring also altered gene regulation.

The final strain proved viable and was able to grow in a range of typical laboratory conditions, albeit a little less vigorously than its natural counterpart. It no longer uses the stop codon TAG or the two serine codons TCG and TCA, so the cellular machinery that recognizes these can now be either deleted or reassigned to recruit ‘non-canonical’ amino acids beyond the usual 20 used by most living cells. Such recruitment has already been shown to be useful in the 63-codon E. coli, both for biotechnology projects, in which non-canonical amino acids are encoded into desired sequence positions to provide residues that can take part in chemical reactions that natural proteins can’t; and for biosafety reasons, in that the natural transfer of readable DNA-encoded information in and out of the synthetic E. coli is limited because the cell operates with a slightly different genetic code from the rest of the natural world5. Expect all of these applications to be expanded in the new 61-codon E. coli, which has the potential to encode the use of more than one non-canonical amino acid, and to generate a more stringent genetic firewall (because 3 of the 64 codons are no longer recognized).

Synthesis of a 4-million-base-pair genome and reduction of the genetic code to 61 codons are new records for synthetic genomics, but might not be for much longer. The international Sc2.0 consortium is closing in on synthesizing all 16 chromosomes of the 12-million-base-pair S. cerevisiae genome — the first synthetic genome of a eukaryotic organism, the group that includes plants, animals and fungi — and the synthesis of a 57-codon E. coli genome is also under way1,7. A genome of the bacterium Salmonella Typhimurium that has two fewer codons than the natural organism is also being

constructed8. This could one day enable bacteria with synthetic genomes to be used as cell-based technologies in the human gut.

From a technological standpoint, the most interesting aspect of all these different projects is that the workflows for synthetic-genome construction are remarkably similar, with kilobase sections of synthesized DNA being assembled (by the process of homologous recombination) into 50- to 100-kilobase pieces in yeast cells, and these pieces then being used to replace natural sequences inside the target organism (by selectable recombination methods). Standardization of methods will enable steps to be automated and more research groups to enter the field. Genome minimization and codon reduction are just the first uses of this new technology, which could one day give us functionally reorganized genomes and genomes that are custom designed to direct cells to perform specialized tasks.

References1. Richardson, S. M. et al. Science 355, 1040–1044 (2017).2. Hutchison, C. A. III et al. Science 351, aad6253 (2016).3. Fredens, J. et al. Nature 569, 514–518 (2019).4. Pósfai, G. et al. Science 312, 1044–1046 (2006).5. Lajoie, M. J. et al. Science 342, 357–360 (2013).6. Wang, K. et al. Nature 539, 59–64 (2016).7. Ostrov, N. et al. Science 353, 819–822 (2016).8. Lau, Y. H. et al. Nucleic Acids Res. 45, 6971–6980 (2017).

Bonomo, A.S., Zeng, L., Damasso, M., Leinhardt, Z.M., Justesen, A.B., Lopez, E., Lund, M.N., Malavolta, L., Silva Aguirre, V., Buchhave, L.A., Corsaro, E., Denman, T., Lopez-Morales, M., Mills, S.M., Mortier, A., Rice, K., Sozzetti, A., Vanderburg, A., Affer, L., Arentoft, T., Benbakoura, M., Bouchy, F., Christensen-Dalsgaard, J., Collier Cameron, A., Cosentino, R., Dressing, C.D., Dumusque, X., Figueira, P., Fiorenzano, A.F.M., García, R.A., Handberg, R., Harutyunyan, A., Johnson, J.A., Kjeldsen, H., Latham, D.W., Lovis, C., Lundkvist, M.S., Mathur, S., Mayor, M., Micela, G., Molinari, E., Motalebi, F., Nascimbeni, V., Nava, C., Pepe, F., Phillips, D.F., Piotto, G., Poretti, E., Sasselov, D., Ségransan, D., Udry, S., Watson, C., 2019. A giant impact as the likely origin of different twins in the Kepler-107 exoplanet system. Nature Astronomy 3, 416-423.

https://doi.org/10.1038/s41550-018-0684-9

Measures of exoplanet bulk densities indicate that small exoplanets with radius less than 3 Earth radii (R⊕) range from low-density sub-Neptunes containing volatile elements to higher-density rocky planets with Earth-like or iron-rich (Mercury-like) compositions. Such astonishing diversity in observed small exoplanet compositions may be the product of different initial conditions of the planet-formation process or different evolutionary paths that altered the planetary properties after formation. Planet evolution may be especially affected by either photoevaporative mass loss induced by high stellar X-ray and extreme ultraviolet (XUV) flux or giant impacts. Although there is some evidence for the former, there are no unambiguous findings so far about the occurrence of giant impacts in an exoplanet system. Here, we characterize the two innermost planets of the compact and near-resonant system Kepler-107 We show that they have nearly identical radii (about 1.5–1.6R⊕), but the outer planet Kepler-107 c is more than twice as dense (about 12.6 g cm–3) as the innermost Kepler-107 b (about 5.3 g cm−3). In consequence, Kepler-107 c must have a larger iron core fraction than Kepler-107 b. This imbalance cannot be explained by the stellar XUV irradiation, which would conversely make the more-irradiated and less-massive planet Kepler-107 b denser than Kepler-107 c. Instead, the dissimilar densities are consistent with a giant impact event on Kepler-107 c that would

have stripped off part of its silicate mantle. This hypothesis is supported by theoretical predictions from collisional mantle stripping10, which match the mass and radius of Kepler-107 c.

Bontognali, T.R.R., 2019. Anoxygenic phototrophs and the forgotten art of making dolomite. Geology 47, 591-592.

https://doi.org/10.1130/focus062019.1

Dolomite [CaMg(CO3)2] is abundant in ancient rocks and rare in younger ones; why is unclear. Evidence is now emerging (Daye et al., 2019, p. 509 in this issue of Geology) that primitive microbes can mediate the formation of dolomite, and they apparently do it better than their younger and more-evolved descendants (DiLoreto et al., 2019). If this is only a coincidence, it is an intriguing one!

Among the many minerals that occur in the geological record, dolomite is surely among those whose formation mechanism has been most studied, discussed and energetically debated (e.g., McKenzie, 1991; Arvidson and Mackenzie, 1999; Warren, 2000; Petrash et al., 2017). Such debate, often referred to as “the Dolomite Problem,” stems from the difficulty of precipitating dolomite in laboratory experiments conducted at low temperatures (Land, 1998) although, in some modern environments, dolomite is evidently forming at temperatures lower than 50 °C (e.g., Illing and Taylor, 1993). Moreover, dolomite is abundant in Precambrian sedimentary rocks, while its presence becomes progressively rarer in younger sediments (McKenzie, 1991). This observation suggests the existence of a link between global environmental change and dolomite formation, but the nature of this change remains elusive (Burns et al., 2000).

In 1995, Vasconcelos et al. proposed that dolomite formation at low temperature might be the result of microbial activity, adding a new “multidisciplinary dimension” to this field of research. Besides being a possible solution to the long-standing Dolomite Problem, this idea also gave a new exciting significance to dolomite: some dolomites that form at low temperature may represent a biosignature, evidence for past microbial activity. This hypothesis is particularly captivating for the study of early life. Indeed, many Precambrian stromatolites (laminated accretionary sedimentary structures that are interpreted as fossils of microbial mats) have laminae consisting of dolomite (Wright and Tucker, 1990; Wright, 2000; Allwood et al., 2009). It would, therefore, be remarkable to conclude that not only the morphology, but also the mineralogy of these structures points to past microbial activity.

The reasons for being excited about the microbial dolomite hypothesis are clear. However, despite the more than 20 years that have passed since the inception of the “microbial model,” many aspects of this mineralization process remain too ambiguous to allow for establishing a solid link between microbes and some ancient dolomites. Indeed, it is yet unclear which microbes (which phyla of the various domains) can mediate dolomite formation, and whether such process is favored—or occurs exclusively—within a defined window of environmental conditions (i.e., specific water chemistry, Mg/Ca ratio, salinity, temperature, pH, alkalinity; McCormack et al., 2018). To interpret dolomite as a biosignature, it is also essential to find a way of differentiating microbial dolomite from abiotic dolomite that forms at high temperatures, precipitating from hydrothermal fluids or by metamorphic replacement of other primary carbonate minerals. Unfortunately, at least for now, there is no distinctive geochemical or morphological signature that can be uniquely attributed to microbial dolomite (Petrash et al., 2017).

In addition to all these uncertainties, the validity of the microbial model was recently attacked at its foundations by reviewing and questioning the interpretation of previously published data on the subject. Gregg et al. (2015) concluded that all Mg-rich carbonates produced by microbes in laboratory experiments lack evidence for cation ordering. Even though Ca2+ and Mg2+ are present, in (or close

to) the right proportion, they are not arranged in alternating layers within the crystal lattice, which is the key crystallographic characteristic differentiating dolomite from calcite. Many researchers feel comfortable with the hypothesis that, once the chemistry of dolomite is achieved, crystal ordering will happen spontaneously in time. This explains the widespread use of the term “protodolomite” to refer to a mineral with the chemistry of dolomite but lacking X-ray diffraction–detectable ordering peaks. However, Gregg et al. (2015) points out that there is no demonstration that such microbially mediated mineral phases will actually evolve into the ordered dolomite found in the geological record.

The study by Daye et al. (2019) provides important new momentum to the field of microbial dolomite, by possibly solving the abovementioned “lack of ordering” issue and by providing new insight on which microbes, and under which environmental conditions, may have produced the petrographic textures observed in some Archean and Proterozoic stromatolites. The article reports results of laboratory experiments in which dolomite was precipitated within biofilms of anoxygenic phototrophic microbes, grown in the presence of Mn2+.

The fact that dolomite that was formed in the experiments of Daye et al. shows some signs of cation ordering already after two weeks is important, not only in view of the concerns expressed by Gregg et al. (2015), but also because it demonstrates that some dolomites present in ancient rocks may be primary minerals. Some dolomites not excessively compromised by late-stage metamorphic processes might, therefore, record geochemical signals inherited directly from seawater/porewaters. This is essential for paleoenvironmental reconstructions, and contrasts with the view that all ancient dolomites are bad targets for geochemical proxies, as they record, at best, the composition of diagenetic fluids.

Active anoxygenic photosynthetic microbial cells, exopolymeric substances (EPS), and the presence of Mn2+ are identified by Daye et al. as the key factors for the mineralization process. While EPS has been proposed as important in several previous studies on dolomite formation (e.g., Bontognali et al., 2010, 2014; Zhang et al., 2012; Roberts, et al., 2013), the addition of Mn2+ to the bacterial growth media represents a more rare and innovative approach. The mechanistic role of this transition metal for the mineralization process remains unexplained, but the results pointing to a catalytic role are consistent with observations made in natural environments, where dolomite occurs within buried microbial mats in chemofacies associated with Mn-S redox cycling (Petrash et al., 2015).

Anoxygenic phototrophs are organisms that use electron donors other than water, and that do not produce molecular oxygen. Their metabolism is considered to be much older than oxygenic photosynthesis, and may have prevailed during the early history of our planet, maybe even for longer than previously thought (i.e., until the time slightly predating the Paleoproterozoic rise of oxygen) (Fischer et al., 2016). Accordingly, Daye et al. suggest that a microbially mediated process orchestrated by anoxygenic phototrophs may explain the preservation of microbial textures before the oxygenation of the oceanic photic zone.

The work of Daye et al. does not provide a direct comparison of oxygenic versus anoxygenic phototrophs in respect to their ability to form dolomite under the same experimental conditions. However, such a comparison was made in a recent study on dolomite formation within natural microbial mats colonizing some hypersaline ponds in the sabkhas of Qatar (Fig. 1) (DiLoreto et al., 2019). Consistent with what is observed in the experiments of Daye et al., that study has revealed the presence of ordered dolomite in mats whose uppermost layer was dominated by anoxygenic phototrophs (Fig. 1B), while only very high-Mg calcite was detected within mats dominated by oxygenic cyanobacteria that occur in the same area of the sabkha.

Redox conditions within microbial mats do not represent global ocean chemistry, and the diversity of a single microbial mat is far from being a representative snapshot of the evolution of life at a given

time of our planet’s history. That said, in the light of these new findings linking dolomite to anoxygenic phototrophs, it is difficult to refrain from formulating the following hypothesis: were early microorganisms better at making dolomite than their younger descendants? Does this explain the generally declining abundance of dolomite throughout the geological record?

References

Allwood, A.C., Grotzinger, J.P., Knoll, A.H., Burch, I.W., Anderson, M.S., Coleman, M.L., and Kanik, I., 2009, Controls on development and diversity of Early Archean stromatolites: Proceedings of the National Academy of Sciences of the United States of America , v. 106, p. 9548–9555, https://doi.org/10.1073/pnas.0903323106.

Arvidson, R.S., and Mackenzie, F.T., 1999, The dolomite problem; Control of precipitation kinetics by temperature and saturation state: American Journal of Science , v. 299, p. 257–288, https://doi.org/10.2475/ajs.299.4.257.

Bontognali, T.R.R., McKenzie, J.A., Warthmann, R.J., and Vasconcelos, C., 2014, Microbially influenced formation of Mg-calcite and Ca-dolomite in the presence of exopolymeric substances produced by sulphate-reducing bacteria: Terra Nova , v. 26, p. 72–77, https://doi.org/10.1111/ter.12072.

Bontognali, T.R., Vasconcelos, C., Warthmann, R.J., Bernasconi, S.M., Dupraz, C., Strohmenger, C.J., and McKenzie, J.A., 2010, Dolomite formation within microbial mats in the coastal sabkha of Abu Dhabi (United Arab Emirates): Sedimentology , v. 57, p. 824–844, https://doi.org/10.1111/j.1365-3091.2009.01121.x.

Burns, S.J., McKenzie, J.A., and Vasconcelos, C., 2000, Dolomite formation and biogeochemical cycles in the Phanerozoic: Sedimentology , v. 47, p. 49–61, https://doi.org/10.1046/j.1365-3091.2000.00004.x.

Daye, M., Higgins, J., and Bosak, T., 2019, Formation of ordered dolomite in anaerobic photosynthetic biofilms: Geology , v. 47, p. 509–512, https://doi.org/10.1130/G45821.1.

DiLoreto, Z.A., Bontognali, T.R.R., Al Disi, Z.A., Al-Kuwari, H.A.S., Williford, K.H., Strohmenger, C.J., Sadooni, F., Palermo, C., Rivers, J.M., McKenzie, J.A., Tuite, M., and Dittrich, M., 2019, Microbial community composition and dolomite formation in the hypersaline microbial mats of the Khor Al-Adaid sabkhas, Qatar: Extremophiles , v. 23, p. 201–218, https://doi.org/10.1007/s00792-018-01074-4.

Fischer, W.W., Hemp, J., and Johnson, J.E., 2016, Evolution of oxygenic photosynthesis: Annual Review of Earth and Planetary Sciences , v. 44, p. 647–683, https://doi.org/10.1146/annurev-earth-060313-054810.

Gregg, J.M., Bish, D.L., Kaczmarek, S.E., and Machel, H.G., 2015, Mineralogy, nucleation and growth of dolomite in the laboratory and sedimentary environment: A review: Sedimentology , v. 62, p. 1749–1769, https://doi.org/10.1111/sed.12202.

Illing, L.V., and Taylor, J.C., 1993, Penecontemporaneous dolomitization in Sabkha Faishakh, Qatar; Evidence from changes in the chemistry of the interstitial brines: Journal of Sedimentary Research , v. 63, p. 1042–1048.

Land, L.S., 1998, Failure to precipitate dolomite at 25 °C from dilute solution despite 1000-fold oversaturation after 32 years: Aquatic Geochemistry , v. 4, p. 361–368, https://doi.org/10.1023/A:1009688315854.

McCormack, J., Bontognali, T.R.R., Immenhauser, A., and Kwiecien, O., 2018, Controls on cyclic formation of Quaternary early diagenetic dolomite: Geophysical Research Letters , v. 45, p. 3625–3634, https://doi.org/10.1002/2018GL077344.

McKenzie, J.A., 1991, The dolomite problem: An outstanding controversy, in Moiler, D.W., McKenzie, J.A., and Weissert, H., eds., Controversies in Modern Geology: London , Academic Press, p. 37–54.

Petrash, D.A., Lalonde, S.V., González-Arismendi, G., Gordon, R.A., Méndez, J.A., Gingras, M.K., and Konhauser, K.O., 2015, Can Mn-S redox cycling drive sedimentary dolomite formation? A hypothesis: Chemical Geology , v. 404, p. 27–40, https://doi.org/10.1016/j.chemgeo.2015.03.017.

Petrash, D.A., Bialik, O.M., Bontognali, T.R., Vasconcelos, C., Roberts, J.A., McKenzie, J.A., and Konhauser, K.O., 2017, Microbially catalyzed dolomite formation: From near-surface to burial: Earth-Science Reviews , v. 171, p. 558–582, https://doi.org/10.1016/j.earscirev.2017.06.015.

Roberts, J. A. et al. , 2013, Surface chemistry allows for abiotic precipitation of dolomite at low temperature: Proceedings of the National Academy of Sciences of the United States of America , v. 110, p. 14540–14545 https://doi.org/10.1073/pnas.1305403110.

Vasconcelos, C., McKenzie, J.A., Bernasconi, S., Grujic, D., and Tiens, A.J., 1995, Microbial mediation as a possible mechanism for natural dolomite formation at low temperatures: Nature , v. 377, p. 220–222, https://doi.org/10.1038/377220a0.

Warren, J., 2000, Dolomite: Occurrence, evolution and economically important associations: Earth-Science Reviews , v. 52, p. 1–81, https://doi.org/10.1016/S0012-8252(00)00022-2.

Wright, D.T., 2000, Benthic microbial communities and dolomite formation in marine and lacustrine environments—A new dolomite model, in Glenn, C.R., et al. , eds., Marine Authigenesis: From Global to Microbial : Society for Sedimentary Geology Special Publications, v. 66, p. 7–14.

Wright, V.P., and Tucker, M.E., 1990, Carbonate Sedimentology: London, Blackwell Scientific Publications, 482 p.

Zhang, F., Xu, H., Konishi, H., Shelobolina, E.S., and Roden, E.E., 2012, Polysaccharide-catalyzed nucleation and growth of disordered dolomite: A potential precursor of sedimentary dolomite: The American Mineralogist , v. 97, p. 556–567, https://doi.org/10.2138/am.2012.3979.

Borruel-Abadía, V., Barrenechea, J.F., Galán-Abellán, A.B., De la Horra, R., López-Gómez, J., Ronchi, A., Luque, F.J., Alonso-Azcárate, J., Marzo, M., 2019. Could acidity be the reason behind the Early Triassic biotic crisis on land? Chemical Geology 515, 77-86.


In recent years there is growing evidence of the importance of the Smithian-Spathian (Early Triassic) ecological crisis to explain the delayed recovery of life after the Permian-Triassic Boundary mass extinction. This study focuses on sedimentary continental rocks of middle Permian to Middle Triassic age from four different Peritethys basins in subequatorial latitudes. Similar distribution patterns of

aluminum phosphate-sulfate (APS) minerals contents in these rocks in the four studied basins provide evidence of increased acidity during the Smithian-Spathian transition, coinciding with a lack of indicators of organic activity in the same interval. Thus, this period of high acidity on land, may have been one of the causes of this biological crisis. Based on the quantification of APS minerals in the studied sedimentary sequences, we propose that it was not until acidity in the environment diminished, that biotic recovery was possible. APS data may also be useful to interpret other past biotic crises.

Böttner, C., Berndt, C., Reinardy, B.T.I., Geersen, J., Karstens, J., Bull, J.M., Callow, B.J., Lichtschlag, A., Schmidt, M., Elger, J., Schramm, B., Haeckel, M., 2019. Pockmarks in the Witch Ground Basin, Central North Sea. Geochemistry, Geophysics, Geosystems 20, 1698-1719.

https://doi.org/10.1029/2018GC008068

Abstract: Marine sediments host large amounts of methane (CH4), which is a potent greenhouse gas. Quantitative estimates for methane release from marine sediments are scarce, and a poorly constrained temporal variability leads to large uncertainties in methane emission scenarios. Here, we use 2‐D and 3‐D seismic reflection, multibeam bathymetric, geochemical, and sedimentological data to (I) map and describe pockmarks in the Witch Ground Basin (central North Sea), (II) characterize associated sedimentological and fluid migration structures, and (III) analyze the related methane release. More than 1,500 pockmarks of two distinct morphological classes spread over an area of 225 km2. The two classes form independently from another and are corresponding to at least two different sources of fluids. Class 1 pockmarks are large in size (>6 m deep, >250 m long, and >75 m wide), show active venting, and are located above vertical fluid conduits that hydraulically connect the seafloor with deep methane sources. Class 2 pockmarks, which comprise 99.5% of all pockmarks, are smaller (0.9–3.1 m deep, 26–140 m long, and 14–57 m wide) and are limited to the soft, fine‐grained sediments of the Witch Ground Formation and possibly sourced by compaction‐related dewatering. Buried pockmarks within the Witch Ground Formation document distinct phases of pockmark formation, likely triggered by external forces related to environmental changes after deglaciation. Thus, greenhouse gas emissions from pockmark fields cannot be based on pockmark numbers and present‐day fluxes but require an analysis of the pockmark forming processes through geological time.

Plain Language Summary: Marine sediments host large amounts of methane (CH4), which is a potent greenhouse gas. The amount of methane released into the atmosphere is, however, largely unknown making it difficult to implement this methane source in climate models. Here we use geophysical, geochemical, and sedimentological data to map the distribution of fluid escape structures in the central North Sea. More than 1,500 pockmarks, which are circular to semicircular depressions of the seafloor, indicate fluid flow from the subsurface. There are two distinct morphological classes of pockmarks corresponding to at least two different fluid sources. Class 1 pockmarks are large, show active venting, and are located above vertical fluid conduits in the subsurface, which feed fluids from deeper strata. Class 2 pockmarks, which comprise 99.5% of all pockmarks, are smaller and limited to the soft sediments directly below the seafloor. Older pockmarks in the subsurface document distinct phases of pockmark formation, likely triggered by external forces after the retreat of ice in the North Sea. The amount of methane released from natural geological sources based on pockmark numbers may be wrong as these do not take into account the origin and composition of released fluids.

Bradbury, H.J., Turchyn, A.V., 2019. Reevaluating the carbon sink due to sedimentary carbonate formation in modern marine sediments. Earth and Planetary Science Letters 519, 40-49.


Previous attempts to quantify the amount of sedimentary carbonate precipitation in modern marine sediments have been derived from the flux of calcium into the sediments due to diffusion under assumed steady state, the application of Fick's first law, and then extrapolation of these site-specific rates to the global ocean sediment column. This approach is limited, however, as much of the ocean floor has not been sampled. We take a machine learning approach to update and refine the estimate of the amount of sedimentary carbonate precipitation, as well as define whether sedimentary carbonate precipitation is driven by organoclastic microbial sulfate reduction or anaerobic methane oxidation. We identify areas where there is sedimentary carbonate formation using machine learning, based upon oceanic physical and chemical properties including bathymetry, temperature, water depth, distance from shore, and tracers of primary production, and data from the global ODP/IODP database. Our results suggest that the total amount of sedimentary carbonate formation is much lower than previous estimates, at 1.35±0.5×1011 molC/yr. We suggest that this rate is a lower estimate and discuss why machine-learning approaches may always produce lower-bound estimates of global processes. Our calculations suggest that the formation of sedimentary carbonate today is mainly driven by anaerobic methane oxidation (77%), with the remainder attributed to organoclastic sulfate reduction. We use our machine-learning results to speculate the impact that sedimentary carbonate precipitation may have had on the carbon isotope composition of the surface dissolved inorganic carbon reservoir over Earth history.

Brandon, A.M., Criddle, C.S., 2019. Can biotechnology turn the tide on plastics? Current Opinion in Biotechnology 57, 160-166.


Accumulation of plastic pollution in aquatic ecosystems is the predictable result of high demand for plastic functionalities, optimized production with economies of scale, and recalcitrance. Strategies are needed for end-of-life conversion of recalcitrant plastics into useful feedstocks and for transition to materials that are biodegradable, non-bioaccumulative, and non-toxic. Promising alternatives are the polyhydroxyalkanoates (PHAs), a vast family of polymers amenable to decentralized production from renewable feedstocks. Establishment of a global-scale PHA-based industry will require identification of PHAs with tailored properties for use as ‘drop-in’ replacements for existing plastics; use of low-cost renewable/waste-derived feedstocks; high productivity cultures that may be genetically modified microorganisms or non-axenic mixed cultures maintained by selection pressures that favor high PHA-producing strains; and low-cost extraction/purification schemes.



Putative stromatolites and associated carbonate minerals in 1.1 Ga Stoer Group lacustrine sedimentary rocks were analysed to deduce their likely origins. Potential stromatolite examples included finely laminated and sometimes wrinkled carbonate-siliciclastic rocks of the Clachtoll Formation at Clachtoll and Bay of Stoer, and laminated limestone domes of the Poll a’Mhuilt Member (Bay of Stoer Formation) from Enard Bay.

Petrography shows that the lamination and wrinkling of Clachtoll Formation specimens can most logically be explained by abiotic siliclastic sedimentary processes, namely rippling and soft-sediment deformation probably related to de-watering. Electron backscatter diffraction shows that the carbonate in these laminated Clachtoll Formation specimens was calcite, and petrography combined with clumped isotope palaeothermometry indicates it was likely to be part syn-depositional and part burial diagenetic in origin.

The laminated domes of the Poll a’Mhuilt Member are shown to comprise clasts of limestone interlayered with clay, quartz, Na-rich feldspars and micas. Cathodoluminescence revealed the limestone clasts to be composite and built of sub-grains that must have been derived from an earlier, potentially Palaeoproterozoic, carbonate unit. Support for this hypothesis comes from clumped isotope palaeotemperature measurements that indicate the limestone clasts were precipitated or recrystallized under higher temperature conditions than the burial diagenetic calcite found in the Clachtoll Formation. Raman spectra of an organic carbon particle within a laminated dome of the Poll a’Mhuilt Member at Enard Bay are consistent with the organic carbon having been re-worked from the ∼2 Ga Loch Maree Group, and we speculate that this might also be true of the calcite.

Microbial fossils are well known from elsewhere in the Stoer Group, but no conclusive examples were found within the thin-sections examined herein. No conclusive evidence was found to suggest that any of the examined putative stromatolites were biogenic, leading to the conclusion that they are best considered stromatolite-like sedimentary rocks (pseudostromatolites).

Brumley, D.R., Carrara, F., Hein, A.M., Yawata, Y., Levin, S.A., Stocker, R., 2019. Bacteria push the limits of chemotactic precision to navigate dynamic chemical gradients. Proceedings of the National Academy of Sciences 116, 10792-10797.


Significance: The limited precision of sensory organs places fundamental constraints on organismal performance. An open question, however, is whether organisms are routinely pushed to these limits and how limits might influence interactions between populations of organisms and their environment. By combining a method to generate dynamic, replicable resource landscapes, high-speed tracking of freely moving bacteria, a mathematical theory, and agent-based simulations, we show that sensory noise ultimately limits when and where bacteria can detect and climb chemical gradients. Our results suggest that the typical chemical landscapes bacteria inhabit are dominated by noise that masks shallow gradients and that the spatiotemporal dynamics of bacterial aggregations can be predicted by mapping the region where gradient signal rises above noise.

Abstract: Ephemeral aggregations of bacteria are ubiquitous in the environment, where they serve as hotbeds of metabolic activity, nutrient cycling, and horizontal gene transfer. In many cases, these regions of high bacterial concentration are thought to form when motile cells use chemotaxis to navigate to chemical hotspots. However, what governs the dynamics of bacterial aggregations is unclear. Here, we use an experimental platform to create realistic submillimeter-scale nutrient pulses with controlled nutrient concentrations. By combining experiments, mathematical theory, and agent-based simulations, we show that individual Vibrio ordalii bacteria begin chemotaxis toward hotspots of dissolved organic matter (DOM) when the magnitude of the chemical gradient rises sufficiently far above the sensory noise that is generated by stochastic encounters with chemoattractant molecules. Each DOM hotspot is surrounded by a dynamic ring of chemotaxing cells, which congregate in regions of high DOM concentration before dispersing as DOM diffuses and gradients become too noisy for cells to respond to. We demonstrate that V. ordalii operates close to the theoretical limits on chemotactic precision. Numerical simulations of chemotactic bacteria, in which molecule counting

noise is explicitly taken into account, point at a tradeoff between nutrient acquisition and the cost of chemotactic precision. More generally, our results illustrate how limits on sensory precision can be used to understand the location, spatial extent, and lifespan of bacterial behavioral responses in ecologically relevant environments.

Brundrett, M., Yan, W., Velazquez, M.C., Rao, B., Jackson, W.A., 2019. Abiotic reduction of chlorate by Fe(II) minerals: Implications for occurrence and transformation of oxy-chlorine species on Earth and Mars. ACS Earth and Space Chemistry 3, 700-710.


Recent investigations have reported a widespread occurrence of chlorate (ClO3–) and perchlorate

(ClO4–) throughout the solar system, including terrestrial arid environments. ClO3

– and ClO4– are

deposited/accumulated at an approximate equal molar ratio, with some exceptions, such as the Antarctica Dry Valley soils (MDV) and perhaps Martian surface material, where ClO4

– is the dominate ClOx

– species. All known ClO4– production mechanisms produce molar ratios of

ClO3–/ClO4

– equal to or much greater than 1, suggesting that reduced ratios may be due to post-depositional mechanism(s). The objective of this study was to investigate potential iron-mediated abiotic reduction of ClO3

–, similar to transformation mechanisms reported for nitrate (NO3–) by Fe(II)

minerals. Three types of Fe(II)-containing minerals, wüstite (FeO), siderite (FeCO3), and sulfate green rust (GRSO4

2–), were investigated in completely mixed batch reactors as potential ClO3–

reductants at a range of pH (4–9) and iron mineral concentrations (1–10 g/L). ClO3– was

stoichiometrically reduced to chloride (Cl–) by wüstite, siderite, and green rust, but no transformation occurred by dissolved Fe(II). Wüstite and green rust reduced NO3

– but not by siderite. When both NO3

– and ClO3– are reduced simultaneously, ClO3

– is reduced preferentially to NO3–, although the

effect is somewhat concentration-dependent. An increased background salt concentration (NaCl) increased ClO3

– reduction but decreased NO3–. The stability of ClO3

– and subsequent impacts on the ratio of ClO3

–/ClO4– in the environment have implications for understanding the cycling of oxyanions

and stability of iron minerals, and related to this, the ratio of ClO4– and ClO3

– may be an indicator of the past availability of free water. On Mars, these reactions may help to explain the unusually high concentrations of ClO4

– compared to ClO3– and NO3

–.

Bullock, R.J., Perkins, R.A., Aggarwal, S., 2019. In-situ burning with chemical herders for Arctic oil spill response: Meta-analysis and review. Science of The Total Environment 675, 705-716.


With increased oil exploration and marine activity in the warming Arctic, there is an increased risk of future oil spills in the Arctic region. In-situ burning (ISB), along with the use of chemical herders (to thicken the slick of spilled oil) has emerged as a potentially viable oil-spill response technique for various Arctic scenarios. The purpose of this research review is to document the field use, research, and analysis regarding the use of ISB to address an offshore oil spill response in the Arctic, with a specific focus on the use of chemical herders to aid ISB in Arctic waters. The compilation of this work involved a systematic review of available experimental data, studies on actual spill-response events, and resulting recommendations on this topic. Both peer-reviewed and available gray literature from the early 1970s through 2018 were evaluated. Selection criteria centered on herders for use with ISBs, Arctic conditions as they relate to ISB, and operational windows of opportunity and environmental risk for this type of oil spill response. From the available literature, more than a hundred articles are referenced herein, and annotated summaries provided. There is general agreement that ISB should be classified as a viable response option for the Arctic offshore to be

implemented as part of a multi-layered approach (ASTM 2014; Fritt-Rasmussen et al. 2017; NRC 2014; Rolandsen 2018). In addition, there continue to be gaps noted concerning the availability of monitoring/surveillance personnel and equipment, and logistical/safety considerations for working in the Arctic, as well as specific information on the fate and potential impact of herders and burn residue on Arctic receptors (NRC 2014; Nuka 2016; US-DOI and USGS 2011). This review provides background information for researchers, responders, decision-makers, communities, and is a resource when developing and approving an oil spill response plan or planning future research which includes the use of ISB and herders.

Bultel, B., Viennet, J.-C., Poulet, F., Carter, J., Werner, S.C., 2019. Detection of carbonates in martian weathering profiles. Journal of Geophysical Research: Planets 124, 989-1007.

https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/2018JE005845

Abstract: Noachian surfaces on Mars exhibit vertical assemblages of weathering horizons termed as weathering profiles; this indicates that surface water caused alteration of the rocks that required a different, warmer climate than today. Evidence of this early Martian climate with CO2 vapor as the main component causing greenhouse warming has been challenged by the lack of carbonate in these profiles. Here we report the analysis of Compact Reconnaissance Imaging Spectrometer for Mars L-detector data leading to the detections of carbonates using a spectral signature exclusively attributed to them. The carbonates are collocated with hydroxylated minerals in weathering profiles over the Martian surface. The origin of CO2 for the formation of carbonates could be the atmosphere. The widespread distribution of weathering profiles with carbonates over the surface of the planet suggest global interactions between fluids containing carbonate/bicarbonate ions with the surface of Mars in the presence of atmospheric water until around 3.7 billion years ago.

Plain Language Summary: The oldest surface of Mars witnessed an impact of dense and humid atmosphere leading to the formation of hydrated minerals. The analysis of remote sensing data allows identifying carbonates mixed with the hydrated minerals. These associations of carbonates and hydrated minerals are widespread on the surface of the planet. This indicates a planetary‐scale process of formation involving the presence of fluids containing inorganic carbon. This finding allows a better understanding of the environment of Mars during the period suspected to be the most likely to have host habitable environment on the planet.

Burklé-Vitzthum, V., Leguizamon Guerra, N.C., Lorgeoux, C., Faure-Catteloin, D., Bounaceur, R., Michels, R., 2019. Influence of H2S on the thermal cracking of alkylbenzenes at high pressure (70 MPa) and moderate temperature (583–623 K). Journal of Analytical and Applied Pyrolysis 140, 423-433.


The thermal cracking of n-butylbenzene was experimentally studied in the presence of H2S (80% : 20% mol) at high pressure (70 MPa), moderate temperature (583, 603 and 623 K) and for durations of 3, 7 and 15 days. The pyrolysis was performed in sealed gold tubes under isobaric conditions. Under these conditions, the conversion of n-butylbenzene varied between 2.5% and 73.2%. The pyrolysis of n-butylbenzene is accelerated by H2S by a factor of up to 3.6 depending on the operating conditions. This acceleration factor seems to decrease with increasing time and temperature. The apparent activation energy of the pyrolysis of n-butylbenzene decreases from 66.6 kcal/mol (pure n-butylbenzene) to 55.9 kcal/mol (n-butylbenzene in mixture with H2S). The main hydrocarbons produced are alkylbenzenes (mostly toluene and ethylbenzene), branched alkylbenzenes (mostly

isomers of iso-butylbenzene and iso-heptylbenzene to a smaller extent) and short alkanes (from CH4 to C3). Several sulfur compounds are also produced and their relative abundances are in the range 4–16% depending on the operating conditions. These sulfur compounds are mostly short thiols (methanethiol, ethanethiol and propanethiols), phenylbutanethiols and phenylthiophenes. Additional experiments were also conducted with alkylbenzenes bearing shorter substituents than n-butylbenzene (toluene, ethylbenzene and n-propylbenzene) in order to hightlight the influence of the length of the side chain. Finally, the kinetic effect of H2S on the pyrolysis of n-butylbenzene was compared to its effect on n-octane pyrolysis: the effect seems antagonistic under the studied experimental conditions but some similarities can be highlighted.

Butina, T.V., Bukin, Y.S., Krasnopeev, A.S., Belykh, O.I., Tupikin, A.E., Kabilov, M.R., Sakirko, М.V., Belikov, S.I., 2019. Estimate of the diversity of viral and bacterial assemblage in the coastal water of Lake Baikal. FEMS Microbiology Letters 366, Article fnz094.

https://doi.org/10.1093/femsle/fnz094

In this study, we analysed the diversity and composition of double-stranded DNA viral and bacterial communities within the sample of surface coastal water of Southern Baikal through metagenomics and deep sequencing of the 16S ribosomal RNA gene, respectively. The 16S rRNA gene analysis has revealed 14 phyla and dominance of the ‘Actinobacteria’ (43.6%), ‘Proteobacteria’ (25.2%) and ‘Bacteroidetes’ (11.5%). The bacterial composition was similar to that obtained previously in Lake Baikal littoral zone. Out of 1 030 169 processed virome reads, 37.4% of sequences (385 421) were identified as viral; 15.1% were identified as nonviral and related to the domains Eukarya, Bacteria and Archaea; and 47.5% had no matches in the databases. The identified virotypes belonged to different families and were predicted to infect a wide range of organisms, from bacteria to mammals. Six families (Myoviridae, Poxviridae, Mimiviridae, Siphoviridae, Phycodnaviridae and Podoviridae) were dominant accounting for more than 90% of the identified sequences (48.3%, 17.4%, 8.3%, 6.8%, 5.8% and 4.1%, respectively). In contrast to other freshwater systems, high percentage of the Poxviridae and Mimiviridae was recorded in the water sample of Lake Baikal.

Caballero-Gill, R.P., Herbert, T.D., Dowsett, H.J., 2019. 100-kyr paced climate change in the Pliocene warm period, southwest Pacific. Paleoceanography and Paleoclimatology 34, 524-545.

https://doi.org/10.1029/2018PA003496

The mid to late Pliocene (~4.2–2.8 Ma.) represents an experiment in climate sensitivity to orbital pacing in which nearly all continental ice was confined to the Southern Hemisphere. Most studies have emphasized the dominant role of obliquity in determining changes in ice volume and temperature at this time, although most records come from the Northern Hemisphere, instead of the hemisphere where the bulk of ice resided. We present the first orbitally‐resolved, mid to late Pliocene Southern Hemisphere paired records of surface and subsurface variability from two deep ocean archives from the Southwest Pacific Ocean (Sites 594 and 1125). These records indicate dominance of low frequencies centered at ~100 kyr for this time period. Because these signatures extend coherently and synchronously from middepth water properties (δ13C, δ18O of benthic foraminifera), which have their chemistry set in the subantarctic belt, to the surface (alkenone‐derived surface temperature estimates, color reflectance, and magnetic susceptibility), we infer that the fingerprint of the ~100‐kyr cycles must have extended over a large region of the Southern Hemisphere. We propose that nonlinearities in climate response to precessional forcing—most likely through ice sheet and/or carbon cycle behavior—generated the observed low frequency. A review of published mid to late Pliocene time series suggests that the ~100‐kyr pacing may be a widespread phenomenon and that

major approximately 100‐kyr excursions in Pliocene climate were an important overlay to the underlying 41‐kyr glacial‐interglacial rhythm. These results caution against uncritical use of existing Pliocene isotopic templates to construct high‐resolution age models.

Cafferty, B.J., Ten, A.S., Fink, M.J., Morey, S., Preston, D.J., Mrksich, M., Whitesides, G.M., 2019. Storage of information using small organic molecules. ACS Central Science 5, 911-916.

https://doi.org/10.1021/acscentsci.9b00210

Although information is ubiquitous, and its technology arguably among the highest that humankind has produced, its very ubiquity has posed new types of problems. Three that involve storage of information (rather than computation) include its usage of energy, the robustness of stored information over long times, and its ability to resist corruption through tampering. The difficulty in solving these problems using present methods has stimulated interest in the possibilities available through fundamentally different strategies, including storage of information in molecules. Here we show that storage of information in mixtures of readily available, stable, low-molecular-weight molecules offers new approaches to this problem. This procedure uses a common, small set of molecules (here, 32 oligopeptides) to write binary information. It minimizes the time and difficulty of synthesis of new molecules. It also circumvents the challenges of encoding and reading messages in linear macromolecules. We have encoded, written, stored, and read a total of approximately 400 kilobits (both text and images), coded as mixtures of molecules, with greater than 99% recovery of information, written at an average rate of 8 bits/s, and read at a rate of 20 bits/s. This demonstration indicates that organic and analytical chemistry offer many new strategies and capabilities to problems in long-term, zero-energy, robust information storage.

Cai, C., Tang, Y., Li, K., Jiang, K., Jiang, C., Xiao, Q., 2019. Relative reactivity of saturated hydrocarbons during thermochemical sulfate reduction. Fuel 253, 106-113.


Tazhong and four other well-known TSR-altered petroleum reservoirs from around the world were analyzed for their molecular and carbon isotopic compositions of saturated hydrocarbons, thiaadamantanes concentrations or H2S contents to determine the relative stability of saturated hydrocarbons during thermochemical sulfate reduction (TSR). We find that TSR does not preferentially deplete tricyclic terpanes and 17α, 21β hopanes with the “exposed” tertiary carbon atoms compared to 18α (H)-22, 29, 30-trisnorhopane (Ts) and C29Ts that have no tertiary carbon atoms, as proposed by Xia and Gong [35]. However, pristane (Pr) and phytane (Ph) seem to have been preferentially oxidized over normal C17 and C18 alkanes, respectively, resulting in decreasing Pr/nC17 and Ph/nC18 ratios with increasing extent of TSR for the Tazhong and Nisku oils and condensates. iC4 appears to be preferentially depleted relative to nC4 during early TSR stage. At later TSR stage both nC3 and nC4 are oxidized more readily than iC4 in the Mobile Bay Norphlet Formation condensates. Thus, we tentatively propose that relative oxidization order during TSR may start with long chain iso-alkanes followed by n-alkanes, then cycloalkanes, C2-C4 alkanes and finally methane; however, it seems that oxidization of these compounds overlaps significantly.

Cañas-Jaimes, D.-L., Cabanzo, R., Mejía-Ospino, E., 2019. Comparison of interfacial tension reduction in a toluene/water system by Colombian crude oil and its interfacially active components. Energy & Fuels 33, 3753-3763.


It is generally accepted that asphaltenes are the main stabilizing agents of water-in-crude-oil emulsions. However, the phenomenon of formation and stabilization of the colloid is complex and requires further studies. In this work, interfacially active species were extracted from samples of three Colombian oil fields. The asphaltenes were obtained by the Soxhlet method. Then, the interfacial material (IM) from crude oil was obtained by a recently proposed wet silica methodology. The former extraction method is based on the solubility criterion, in contrast to the latter method that allows for the acquisition of substances by their affinity with water. The materials extracted were characterized by nuclear magnetic resonance, laser desorption/ionization mass spectroscopy, Fourier transform infrared spectroscopy, and Raman spectroscopy. Finally, we evaluate the contribution of asphaltenes and IM in interfacial tension (IFT) reduction, which is one important mechanism in the formation and stabilization of emulsions. Solutions of crude oil, asphaltenes, and IM were prepared in toluene, and their effect on IFT against water was measured using pendant drop tensiometry. We found that IM extracted by the wet silica method reduces IFT considerably more than the asphaltenes. We also prepared solutions with extracted asphaltenes and crude oil and compare the IFT reduction in equivalent asphaltene concentrations. We conclude that, for one of the samples, the presence of the other fractions does not contribute to the IFT reduction and that the asphaltenes are the main surfactant in that case. In contrast, the IFT reduction caused by the non-asphaltene fraction in the other two samples was observed. We proposed this methodology to evaluate the importance of asphaltenes in the IFT alteration. The identification of the most surfactant-rich crude oil fraction can be used to choose the appropriate approach to solve water–crude oil interfacial-associated problems.



This paper presents a modified perturbed chain-statistical association fluid theory (mod-PC-SAFT EoS) obtained by including into PC-SAFT the second-order dispersion term developed originally by Zhang [Fluid Phase Equilibria, 154 (1999) 1–10] for pure components. This version of PC-SAFT was then used to predict asphaltene onset pressures (AOPs) for nine petroleum reservoir fluids with asphaltene contents, based on saturates-aromatics-resins-asphaltenes (SARA) analyses, varying from 0.80 to 16 wt%. In all modeled cases, this new version predicted less accelerated AOPs at low temperatures than the original PC-SAFT, and then the well-known and widely discussed tendency of PC-SAFT of predicting very high AOPs at these conditions was corrected. The new model also reduced or eliminated the crossover temperatures predicted by PC-SAFT when a reservoir fluid, prone to precipitate asphaltenes, was enriched with CO2.



The study discusses the presence, formation and destruction of graphitic material in fault rocks of exhumed fault zones. Because of the low strength, the presence of lubricating graphitic material along fault zones has important implications for understanding tectonic movements in various crustal levels. Fault zones are permeable for ascending and descending fluids and represent, therefore, effective pathways of fluids between deep lithospheric levels and Earth's surface, and this plumbing system is part of the carbon exchange system of the global carbon cycle between deep lithosphere and

atmosphere. Processes of formation, structure and microfabrics of the graphitic material and the implications for the global carbon cycle in natural fault zones are still poorly understood. This paper gives an overview on the range of the origin of graphitic material along fault zones (e.g. organic vs. carbonatic vs. fluid origin) and its physical formation and destruction mechanisms. The presence of graphitic carbon permits: (1) to recognize faults with graphitic lubricants during faulting and allow assess, therefore, crustal strength over various temporal and spatial scales, (2) how carbon-bearing material is moving through the fault zone hence recording the complex structural history, (3) how carbon represents a monitor of fluid transport through fault zones, and (4) how graphitic material allow to pinpoint peak temperature conditions of the faulting process. The data implies also carbon transfer between depth and surface, which contributes to the global carbon cycle, but to a hitherto unknown extent. The presence of graphitic carbon in fault rocks has also implications on fault mechanics, engineering geology, nuclear waste repositories and assessment of seismic hazard.

Cardoso-Saldaña, F.J., Kimura, Y., Stanley, P., McGaughey, G., Herndon, S.C., Roscioli, J.R., Yacovitch, T.I., Allen, D.T., 2019. Use of light alkane fingerprints in attributing emissions from oil and gas production. Environmental Science & Technology 53, 5483-5492.


Spatially resolved emission inventories were used with an atmospheric dispersion model to predict ambient concentrations of methane, ethane, and propane in the Eagle Ford oil and gas production region in south central Texas; predicted concentrations were compared to ground level observations. Using a base case inventory, predicted median propane/ethane concentration ratios were 106% higher (95% CI: 83% higher–226% higher) than observations, while median ethane/methane concentration ratios were 112% higher (95% CI: 17% higher–228% higher) than observations. Predicted median propane and ethane concentrations were factors of 6.9 (95% CI: 3–15.2) and 3.4 (95% CI: 1.4–9) larger than observations, respectively. Predicted median methane concentrations were 7% higher (95% CI: 39% lower–37% higher) than observations. These comparisons indicate that sources of emissions with high propane/ethane ratios (condensate tank flashing) were likely overestimated in the inventories. Because sources of propane and ethane emissions are also sources of methane emissions, the results also suggest that sources of emissions with low ethane/methane ratios (midstream sources) were underestimated. This analysis demonstrates the value of using multiple light alkanes in attributing sources of methane emissions and evaluating the performance of methane emission inventories for oil and natural gas production regions.

Carr, S.A., Jungbluth, S.P., Eloe-Fadrosh, E.A., Stepanauskas, R., Woyke, T., Rappé, M.S., Orcutt, B.N., 2019. Carboxydotrophy potential of uncultivated Hydrothermarchaeota from the subseafloor crustal biosphere. The ISME Journal 13, 1457-1468.

https://doi.org/10.1038/s41396-019-0352-9

The exploration of Earth’s terrestrial subsurface biosphere has led to the discovery of several new archaeal lineages of evolutionary significance. Similarly, the deep subseafloor crustal biosphere also harbors many unique, uncultured archaeal taxa, including those belonging to Candidatus Hydrothermarchaeota, formerly known as Marine Benthic Group-E. Recently, Hydrothermarchaeota was identified as an abundant lineage of Juan de Fuca Ridge flank crustal fluids, suggesting its adaptation to this extreme environment. Through the investigation of single-cell and metagenome-assembled genomes, we provide insight into the lineage’s evolutionary history and metabolic potential. Phylogenomic analysis reveals the Hydrothermarchaeota to be an early-branching archaeal phylum, branching between the superphylum DPANN, Euryarchaeota, and Asgard lineages.

Hydrothermarchaeota genomes suggest a potential for dissimilative and assimilative carbon monoxide oxidation (carboxydotrophy), as well as sulfate and nitrate reduction. There is also a prevalence of chemotaxis and motility genes, indicating adaptive strategies for this nutrient-limited fluid-rock environment. These findings provide the first genomic interpretations of the Hydrothermarchaeota phylum and highlight the anoxic, hot, deep marine crustal biosphere as an important habitat for understanding the evolution of early life.

Cassel, M.C., Lavina, E.L.C., Cagliari, J., Rodrigues, R., Pereira, E., 2019. Anoxia and salinity changes: a new Permian catastrophe record. Climate of the Past Discussions 2019, 1-20.

https://www.clim-past-discuss.net/cp-2019-46/

Bituminous shales are associated to worldwide geological events, such as mass extinction, anoxia and climatic changes, mainly when preserved in carbonate ramps, and constitute reliable records of this dynamics. However, a minority of data still exist that measure the Permian, especially in the Southern Hemisphere associated to Panthalassic Ocean as compared to numerous studies of Oceanic Anoxic Events in the Cretaceous or associated to Tethys. The Late Permian extinction was the most severe extinction of the past 500 million years, which wiped out over 90 % of marine species. Before the Permian-Triassic boundary (e.g. Early-Middle Permian successions) geochemical and geological anomalous aspects has received more attention due the information about the Late Paleozoic icehouse-greenhous transitions, which is one of the triggers for the catastrophic ectinction. Therefore the Irati Formation, Permian interval of Paraná Basin in southern Brazil, is suitable for the study of these intricate processes due to the presence of Permian bituminous shales and carbonates. Based on core descriptions, spectral gamma ray data and organic geochemistry, a stratigraphic scheme is here proposed to support paleoenvironmental inferences. We identified three depositional sequences formed internally by T-R cycles of highest frequency. The sedimentary facies analysis indicates a carbonate ramp subdivided into outer, middle and inner. Climatic and sea level changes are defined, and also oscillations in the salinity, oxygenation and organic matter source. Bituminous shales record normal salinity, with anoxia levels and even euxinia, associated to the increase in bioproductivity. Carbonate facies register periods of hypersalinity under oxic environment and semi-arid conditions. The accumulation of Mesosaurus skeletal remains results from the action of reworking fluxes, creating an endemic facies in this region. Climatic versus eustatic influence were differentiated, and also the controlling hierarchies. These results are evidence for the environmental dynamics from the Permian, that generated extreme global events, mainly in Gondwana.

Caulton, D.R., Lu, J.M., Lane, H.M., Buchholz, B., Fitts, J.P., Golston, L.M., Guo, X., Li, Q., McSpiritt, J., Pan, D., Wendt, L., Bou-Zeid, E., Zondlo, M.A., 2019. Importance of superemitter natural gas well pads in the Marcellus Shale. Environmental Science & Technology 53, 4747-4754.


A large-scale study of methane emissions from well pads was conducted in the Marcellus shale (Pennsylvania), the largest producing natural gas shale play in the United States, to better identify the prevalence and characteristics of superemitters. Roughly 2100 measurements were taken from 673 unique unconventional well pads corresponding to ∼18% of the total population of active sites and ∼32% of the total statewide unconventional natural gas production. A log-normal distribution with a geometric mean of 2.0 kg h–1 and arithmetic mean of 5.5 kg h–1 was observed, which agrees with other independent observations in this region. The geometric standard deviation (4.4 kg h–1) compared well to other studies in the region, but the top 10% of emitters observed in this study contributed 77% of the total emissions, indicating an extremely skewed distribution. The integrated proportional loss of

this representative sample was equal to 0.53% with a 95% confidence interval of 0.45–0.64% of the total production of the sites, which is greater than the U.S. Environmental Protection Agency inventory estimate (0.29%), but in the lower range of other mobile observations (0.09–3.3%). These results emphasize the need for a sufficiently large sample size when characterizing emissions distributions that contain superemitters.

Cerro-Gálvez, E., Sala, M.M., Marrasé, C., Gasol, J.M., Dachs, J., Vila-Costa, M., 2019. Modulation of microbial growth and enzymatic activities in the marine environment due to exposure to organic contaminants of emerging concern and hydrocarbons. Science of The Total Environment 678, 486-498.


Organic pollutants are continuously being introduced in seawater with uncharacterized impacts on the engines of the marine biogeochemical cycles, the microorganisms. The effects on marine microbial communities were assessed for perfluoroalkyl substances, organophosphate esters flame retardants and plasticizers, polycyclic aromatic hydrocarbons, and n-alkanes. Dose-response experiments were performed at three stations and at three depths in the NW Mediterranean with contrasted nutrient and pollutant concentrations. In these experiments, the microbial growth rates, the abundances of the main bacterial groups, measured by Catalyzed Reporter Deposition Fluorescence In Situ Hybridization (CARD-FISH), and extracellular enzymatic activities, were quantified. Increasing concentrations of organic pollutants (OPs) promoted different responses in the communities that were compound, organism and nutrient availability (trophic status). The largest differences between OP treatments and controls in the growth rates of both heterotrophic and phototrophic microbial groups were observed in seawater from the deep chlorophyll maxima. Furthermore, there was a compound specific stimulation of different extracellular enzymatic activities after the exposure to OPs. Our results revealed that marine microbial communities reacted not only to hydrocarbons, known to be used as a carbon source, but also to low concentrations of organic pollutants of emerging concern in a complex manner, reflecting the variability of various environmental variables. Multiple linear regressions suggested that organic pollutants modulated the bacterial growth and extracellular enzymatic activities, but this modulation was of lower magnitude than the observed pronounced response of the microbial community to nutrient availability.

Chang, H., Zhang, Z., Qiang, L., Gao, T., Lan, T., Sun, M., Xu, L., Ma, X., 2019. Study on the pyrolysis characteristics of a typical low rank coal with hydrothermal pretreatment. Energy & Fuels 33, 3871-3880.


Coal pyrolysis characteristics are closely related to its structure and composition, and revealing the relationship between them is essential for deep understanding of the pyrolysis mechanism. Therefore, in this work, Shendong coal (SDC) was treated by hydrothermal pretreatment (HTP) to change its structure and composition, and the influence of the changes on pyrolysis characteristics was investigated. The changes in physicochemical structure and composition of treated coal samples were characterized by N2 isothermal adsorption, Fourier transform infrared spectroscopy, 13C nuclear magnetic resonance, X-ray diffraction, and inductively coupled plasma optical emission spectrometry. The pyrolysis experiments of raw and treated coal samples were carried out in a fluidized bed reactor. Then, the pyrolysis product distribution, the gas composition, the tar chemical composition and properties, and the char gasification behaviors were comprehensively studied. The experimental results showed the effectiveness of HTP in surface area and pore volume increase,

oxygen removal and transfer, hydrogen radical introduction, and water-soluble inorganic metal removal for SDC. Correspondingly, the distribution and composition of pyrolysis products of treated coal samples changed. The pyrolysis gas quality was improved with more formation of H2 and CH4. The tar yield and N-hexane insoluble component increased. More oxygen was enriched in macromolecular tar instead of gas and char products, enhancing the char gasification activity. In addition, the structure–activity relationship between the changes in coal structure and composition and the pyrolysis characteristics was revealed in this work.

Chaudhary, D.K., Kim, J., 2019. New insights into bioremediation strategies for oil-contaminated soil in cold environments. International Biodeterioration & Biodegradation 142, 58-72.


The exploration of petroleum source, production, and transportation in cold environments is increasing tremendously. These activities have made cold regions of the earth vulnerable to oil-contamination. In cold environments, oil-based contaminants persist longer than they do in temperate region because of the low bioavailability of hydrocarbons and the harsh climatic conditions. Oil-based contaminants must be removed to maintain biodiversity and ecological balance. During the last fifteen years, several bioremediation strategies have been employed in cold regions. One effective bioremediation strategy is the introduction of potent cold-adaptive microorganism combining with amendment of physio-chemical parameters into the contaminated sites. However, this approach is still in its infancy compared to the use of mesophilic microorganisms. The current bioremediation practices employed in cold regions suffer with several problems such as lack of potent oil-degraders, poor bioavailability of hydrocarbons, and low temperature, oxygen, and nutrient level. Understanding on these aspects is essential for successful bioremediation in cold environments. This review discusses the current bioremediation strategies, the limiting factors governing bioremediation, and the mechanism of biodegradation in cold regions. Furthermore, culture-independent techniques for assessing potent microbes, laboratory cultivation techniques for isolating psychrophilic oil-degraders and conceptual strategies of bioaugmentation are presented.

Chaudhary, R., Dhepe, P.L., 2019. Depolymerization of lignin using a solid base catalyst. Energy & Fuels 33, 4369-4377.


Lignin extraction from lignocellulosic biomass has attracted considerable attention for an alternative production of sustainable fuels and chemicals. We report the lignin isolation from coconut coir using Klason, organosolv, and soda methods and the depolymerization of isolated lignin to value-added chemicals using a solid base catalyst. The yield of isolated lignin by the Klason method was found to be about 4 to 6 times higher than that by other methods. The structure of isolated Klason lignin (CC-KL), organosolv lignin (CC-ORGL), and soda lignin (CC-SL) was studied using attenuated total reflection (ATR), NMR, microanalysis, and so forth. The monomer molecular formula derived from microanalysis suggested that coir lignin is rich in guaiacyl units. ATR and 13C NMR clearly indicate that CC-ORGL contains more C–C bonds compared to CC-KL and CC-SL. Subsequently, these isolated lignins were depolymerized over a solid base catalyst (NaX) under atmospheric pressure. CC-SL shows a high yield of aromatic products (28%) compared to CC-ORGL and CC-KL. In order to develop a sustainable future technology, one-pot depolymerization of coconut coir was performed which resulted in a high yield (64%) of aromatic products.



Extraterrestrial materials have He and Ne isotopic compositions that are distinct from those of the Earth's surface. In order to track the extraterrestrial material accreted onto Earth during the Ediacaran period, we have analyzed the He and Ne isotopic composition of thirteen sedimentary rocks in the age range ~550–600 Ma, coming from the Huqf supergroup in Oman for which carbon and sulfur isotopic data have been characterized previously.

3He/4He ratios range between 0.006 ± 0.003 and 0.27 ± 0.01 RA, with RA being the atmospheric ratio. 3He/4He ratios show a positive relationship with 3He contents ranging between 0.6 and 31 × 10−13 cm3 STP·g−1. The 3He contents are within the literature data for 3 to 480 Myr old samples with evidence of IDP 3He (IDP for interplanetary dust particles), suggesting that extraterrestrial 3He is still retained in such old samples.

20Ne/22Ne ratios are close to or below the modern atmospheric ratio of 9.8 with the minimum value equal to 9.05 ± 0.03. 21Ne/22Ne ratios show a high range of variation, going from 0.0345 ± 0.0009 to 0.0935 ± 0.0023. The Ne isotopic compositions follow a nucleogenic trend similar to that of crustal fluids from the literature and predicted continental crust. However, one sample (3404) shows an unusual Ne isotopic composition with a lower 20Ne/22Ne at similar 21Ne/22Ne compared to the other samples.

Two hypotheses can explain this singular Ne isotopic composition. First, it could be the result of a particular nucleogenic trend due to the presence of F-bearing minerals in this sample. SEM-EDS elemental mapping showed that although F- and Ca-rich phases, which could correspond to fluorites, are present in sample 3404. However, their abundance of ~0.15% seems too low to explain the unusual Ne isotopic composition. However, due to the high uncertainty of the calculations, we cannot totally rule out this hypothesis. Alternatively, the singular Ne isotopic composition could be due to the presence of a Ne-A component, a component characterizing pre-solar diamonds contained in chondrites. This would indicate that a major object impacted the Earth at the time the sediment was forming, between ~600 and ~550 Ma, which is coherent with the estimated age range of the Acraman impact in Australia.

Chellamuthu, P., Naughton, K., Pirbadian, S., Silva, K.P.T., Chavez, M.S., El-Naggar, M.Y., Boedicker, J., 2019. Biogenic control of manganese doping in zinc sulfide nanomaterial using Shewanella oneidensis MR-1. Frontiers in Microbiology 10, 938. doi: 10.3389/fmicb.2019.00938.


Bacteria naturally alter the redox state of many compounds and perform atom-by-atom nanomaterial synthesis to create many inorganic materials. Recent advancements in synthetic biology have spurred interest in using biological systems to manufacture nanomaterials, implementing biological strategies to specify the nanomaterial characteristics such as size, shape, and optical properties. Here we combine the natural synthetic capabilities of microbes with engineered genetic control circuits towards biogenically synthesized semiconductor nanomaterials. Using an engineered strain of Shewanella oneindensis with inducible expression of the cytochrome complex MtrCAB, we control the reduction of manganese (IV) oxide. Cytochrome expression levels were regulated using an inducer molecule, which enabled precise modulation of dopant incorporation into manganese doped

zinc sulfide nanoparticles (Mn:ZnS). Thereby, a synthetic gene circuit controlled the optical properties of biogenic quantum dots. These biogenically assembled nanomaterials have similar physical and optoelectronic properties to chemically synthesized particles. Our results demonstrate the promise of implementing synthetic gene circuits for tunable control of nanomaterials made by biological systems.

Chen, B., Sun, H., Li, K., Wang, D., Yang, M., 2019. Experimental investigation of natural gas hydrate production characteristics via novel combination modes of depressurization with water flow erosion. Fuel 252, 295-303.


Depressurization is considered the most efficient method for natural gas hydrates (NGHs) exploitation. However, ice formation, hydrate reformation, and insufficient decomposition driving forces in the later stages of depressurization are the main issues to be solved. In this study, a more effective combination of depressurization with water flow erosion for the production of NGHs was investigated to promote efficient exploitation of methane hydrate (MH) by using in-situ magnetic resonance imaging. Three different MH decomposition modes were used, and water flow erosion was employed to eliminate the problem of incomplete MH decomposition in the later stages of depressurization, which is caused by insufficient driving forces and slower heat and mass transfer due to lower decomposition pressure and the protection effect of water films. The promotion of MH decomposition by water flow erosion was experimentally confirmed. Depressurization could decrease water-phase permeability in the sediment core and further optimize the water flow environment. Water flow erosion could greatly accelerate heat and mass transfer and provided extra driving force by increasing the chemical potential difference in the later stages of depressurization. In addition, the phenomenon of ice formation caused by sudden depressurization could be relieved by water flow erosion, which improved the ambient heat transfer, further changing the MH decomposition characteristics. The mutual promotion of MH decomposition by water flow erosion and depressurization was clearly demonstrated in this study.

Chen, C., Wang, Y., Beagle, J.R., Liao, L., Shi, S., Deng, R., 2019. Reconstruction of the evolution of deep fluids in light oil reservoirs in the Central Tarim Basin by using PVT simulation and basin modeling. Marine and Petroleum Geology 107, 116-126.


To better understand the fluid phase state and its evolution in a deep environment, an integrated PVT simulation and basin modeling method for two light oil reservoirs in the Central Tarim Basin was proposed and applied. The fluid phase models were built using PVT simulation technology after successfully recovering the fluid compositions. The envelopes of fluid from either the Awatage Formation (Є2a) for Well ZS1 or the Wusongar Formation (Є1w) for Well ZS5 show the order from cricondenbar (Pm), critical point (Cp) to cricondentherm (Tm), suggesting a single liquid phase for the present fluids in the Cambrian subsalt dolomite reservoirs. The result of this study indicates that the two reservoirs did not experience phase changes, phase differentiation, or oil cracking and maintained a universal state of the liquid phase over time by combining the evolutionary history of temperature and pressure derived from basin modeling. The fluid density and viscosity experienced relatively complicated fluctuation processes, and the fluctuations of fluid viscosity over geologic history are much more apparent than the variations in fluid density. The density and viscosity of the Awatage Formation (Є2a) for Well ZS1 are found to be lower than those of the Wusongar Formation (Є1w) for Well ZS5. The results reveal that factors, such as good trap conditions, a stable tectonic

background, a low paleo-geothermal gradient (1.6–2.8 °C/100 m), and the weak effect of thermal sulfate reduction (TSR) altogether act on the early-accumulated light oil and gas that has been preserved as a single liquid phase over time. These results are significant for future explorations of large-scale liquid petroleum in Cambrian subsalt dolomite reservoirs of the Central Tarim Basin.

Chen, F., Welker, F., Shen, C.-C., Bailey, S.E., Bergmann, I., Davis, S., Xia, H., Wang, H., Fischer, R., Freidline, S.E., Yu, T.-L., Skinner, M.M., Stelzer, S., Dong, G., Fu, Q., Dong, G., Wang, J., Zhang, D., Hublin, J.-J., 2019. A late Middle Pleistocene Denisovan mandible from the Tibetan Plateau. Nature 569, 409-412.

https://doi.org/10.1038/s41586-019-1139-x

Denisovans are members of a hominin group who are currently only known directly from fragmentary fossils, the genomes of which have been studied from a single site, Denisova Cave in Siberia. They are also known indirectly from their genetic legacy through gene flow into several low-altitude East Asian populations and high-altitude modern Tibetans. The lack of morphologically informative Denisovan fossils hinders our ability to connect geographically and temporally dispersed fossil hominins from Asia and to understand in a coherent manner their relation to recent Asian populations. This includes understanding the genetic adaptation of humans to the high-altitude Tibetan Plateau, which was inherited from the Denisovans. Here we report a Denisovan mandible, identified by ancient protein analysis, found on the Tibetan Plateau in Baishiya Karst Cave, Xiahe, Gansu, China. We determine the mandible to be at least 160 thousand years old through U-series dating of an adhering carbonate matrix. The Xiahe specimen provides direct evidence of the Denisovans outside the Altai Mountains and its analysis unique insights into Denisovan mandibular and dental morphology. Our results indicate that archaic hominins occupied the Tibetan Plateau in the Middle Pleistocene epoch and successfully adapted to high-altitude hypoxic environments long before the regional arrival of modern Homo sapiens.

Chen, G., Fan, Y., Li, Q., 2019. A study of Coalbed Methane (CBM) reservoir boundary detections based on azimuth electromagnetic waves. Journal of Petroleum Science and Engineering 179, 432-443.


In this research, a coal-gangue-rock geological model based on geological parameters was established by studying the relationships between different dielectric constants, conductivity and attenuation coefficients, and emission frequencies when electromagnetic waves were propagated in a medium. The effects of the electromagnetic wave energy attenuations on coal-rock interfaces under different electrical parameters, and the variations in boundary reflection energy under different lithological interface conditions were examined. Also, the influences of the coal gangue interlayers on the boundary detections, as well as the theoretical conditions and basis for electromagnetic wave detections at coal-rock interfaces were obtained. On the aforementioned basis, the parameters design method of azimuth electromagnetic wave resistivity logging tool while drilling were proposed. Then, the applicability potential of the proposed electromagnetic wave coal-rock interface identification method was examined. This research content included the influences of the measuring response signals on the instrument itself under different source distances, transmitting frequencies, and coil installation angles. Also, an external influence analysis of the instrument's distance to formation boundaries and the formation resistivity contrasts were studied in detail. The boundary response characteristics of the electromagnetic wave signals under different coil structures and instrument parameters were obtained using numerical simulations. Furthermore, under the many constraint

conditions, the basis for selecting the parameters of the instruments which were suitable for underground coal mines was put forward.

Chen, L., Hu, B.X., Dai, H., Zhang, X., Xia, C.-A., Zhang, J., 2019. Characterizing microbial diversity and community composition of groundwater in a salt-freshwater transition zone. Science of The Total Environment 678, 574-584.


A salt-freshwater transition zone due to seawater intrusion to groundwater promotes changes in microbial diversity and community composition in a coastal aquifer. The main purpose of this study is to explore the effect of seawater intrusion on the groundwater quality in a salt-freshwater transition zone and identify the microbial fingerprints of seawater intrusion. The changes in microbial community diversity response to the seawater intrusion were characterized by comparing the community structures of the microbes in fresh groundwater, seawater, and salty groundwater from various monitoring wells at different depths using the high throughput 16S rDNA gene sequencing. Results show that seawater had the lowest taxon richness and evenness, and the irrigation water had the highest richness and evenness. Statistical analysis showed that DO%, ORP, and Cl− affected microbial distribution in the groundwater; while DO% was a main environmental factor influencing microbial community diversity. The analysis of microbial community structures indicates that the order Oceanospirillales and the family Alteromonadaceae could be used as indicators of seawater intrusion.


http://www.syxb-cps.com.cn/EN/abstract/abstract5656.shtml

As the important pore type of shale gas reservoirs, nano-organic pores are relatively developed in the marine-rich organic shale of the Upper Ordovician Wufeng Formation and Member 1 of the Lower Silurian Longmaxi Formation (Long 1 Member) in Pingqiao block of the second production phase of the Fuling shale gas field. Using the argon ion polishing-field emission scanning electron microscopy (FE-SEM), Image-Pro Plus statistical software and gas physic adsorption experiments, this study observes and statistically analyzes the shape, number and pore size distribution of organic matter pores in 14 shale core samples from different small layers of the Wufeng Formation and Long 1 Member of Well JY-B in Pingqiao block, and also calculates out the organic surface pore rate. The FE-SEM is used to observe the organic pores of shale samples in Wufeng Formation, of which the shape is mainly polygonal with edge shrinkage. The shale samples in the lower section of Long 1 Member are mostly irregularly elliptical and nearly circular, while those in the upper shale have a flattened elliptical shape, irregularly near-round and elongated. The organic pore size of shale samples is mainly between 5 and 600 nm, and the pore size of organic pores is between 5 and 30 nm. The number of organic pores with the pore size of 100-600 nm is relatively large in the shale of Long 1 Member. The average single-particle organic matter surface pore rate of Wufeng Formation (Layer 1) and the lower part of Long 1 Member (Layer 3) is relatively large, followed by Layer 7 and 8 of the upper Long 1 Member. The organic matter surface rate of Wufeng Formation, the upper Long 1 Member and the upper shale samples have different positive correlations with the total organic carbon. The gas-adsorption experiments show that the cumulative pore volume of the pores of 0.3-10 nm in shale samples has a good linear positive correlation with the total organic carbon, indicating that the organic pores in this part are dominant. The development characteristics and differences of

organic pores in three sets of shale intervals are related to shale organic carbon content, mineral composition and structural extrusion.



The Tibetan Plateau is a critical ecosystem that sensitively responds to ongoing glacier shrinkage and permafrost thaw. Dissolved organic matter (DOM) in Tibetan Alpine rivers plays pivotal roles in the biogeochemical cycling of elements and nutrients at regional and even global scales, impacting water quality, downstream environments, and climate. However, little is known about the characteristics and dynamics of DOM in these watersheds. We investigated five major Himalayan rivers in the southern Tibetan Plateau, utilizing bulk dissolved organic carbon (DOC), optical properties, and molecular formulas. We found extremely low DOC and fluorescent DOM (FDOM) levels in the rivers (average DOC: 0.25–0.87 mg L−1, FDOM: 0.02–0.05 RU) with a highly degraded molecular signature, which was enriched with heteroatomic molecular formulas (S-containing: 58–72%, N-containing: 61–86%) and condensed aromatics (31–39% vs. ∼11% in world major rivers). Further, 81–99% of the condensed aromatics was identified as dissolved black nitrogen (DBN) with multiple nitrogen atoms, typical for grassy biomass combustion. The findings highlighted potentially fast DOM remineralization leading to the release of CO2 and enriched apparently anthropogenic condensed aromatics and heteroatomic formulas in what have been considered pristine Tibetan rivers. These findings should be considered in future biogeochemical models and ecosystem management.

Chen, M., Strömberg, C.A.E., Wilson, G.P., 2019. Assembly of modern mammal community structure driven by Late Cretaceous dental evolution, rise of flowering plants, and dinosaur demise. Proceedings of the National Academy of Sciences 116, 9931-9940.


Significance: Amazing fossil discoveries over the last 30 years have led to the paleontological consensus that some Mesozoic mammaliaforms underwent ecomorphological diversification in the midst of dinosaurs. However, the ecological structure of Mesozoic mammaliaform communities remains unclear. Here, we quantify the ecological structure of extinct and extant small-bodied mammaliaform communities aiming to identify evolutionary and ecological drivers that have influenced those communities through time. We used body size, diet, and locomotion of constituent species to plot ecospace occupation and calculate ecological richness and disparity of those communities. We propose that the interplay of Late Cretaceous dental evolution, the rise of angiosperms, and competition with other vertebrates were critical in shaping the ecological structure of small-bodied mammaliaform communities through time.

Abstract: The long-standing view that Mesozoic mammaliaforms living in dinosaur-dominated ecosystems were ecologically constrained to small size and insectivory has been challenged by astonishing fossil discoveries over the last three decades. By studying these well-preserved early mammaliaform specimens, paleontologists now agree that mammaliaforms underwent ecomorphological diversification during the Mesozoic Era. This implies that Mesozoic mammaliaform communities had ecological structure and breadth that were comparable to today’s small-bodied mammalian communities. However, this hypothesis remains untested in part because the primary focus of most studies is on individual taxa. Here, we present a study quantifying the

ecological structure of Mesozoic mammaliaform communities with the aim of identifying evolutionary and ecological drivers that influenced the deep-time assembly of small-bodied mammaliaform communities. We used body size, dietary preference, and locomotor mode to establish the ecospace occupation of 98 extant, small-bodied mammalian communities from diverse biomes around the world. We calculated ecological disparity and ecological richness to measure the magnitude of ecological differences among species in a community and the number of different eco-cells occupied by species of a community, respectively. This modern dataset served as a reference for analyzing five exceptionally preserved, extinct mammaliaform communities (two Jurassic, two Cretaceous, one Eocene) from Konservat-Lagerstätten. Our results indicate that the interplay of at least three factors, namely the evolution of the tribosphenic molar, the ecological rise of angiosperms, and potential competition with other vertebrates, may have been critical in shaping the ecological structure of small-bodied mammaliaform communities through time.

Chen, S., Deng, H., Liu, G., Zhang, D., 2019. Corrosion of Q235 carbon steel in seawater containing Mariprofundus ferrooxydans and Thalassospira sp. Frontiers in Microbiology 10, 936. doi: 10.3389/fmicb.2019.00936.


Iron-oxidizing bacteria (IOB) and iron-reducing bacteria (IRB) can easily adhere onto carbon steel surface to form biofilm and affect corrosion processes. However, the mechanism of mixed consortium induced carbon steel corrosion is relatively underexplored. In this paper, the adsorptions of IOB (Mariprofundus ferrooxydans, M. f.), IRB (Thalassospira sp., T. sp.) and mixed consortium (M. f. and T. sp.) on surface of Q235 carbon steel and their effects on corrosion in seawater were investigated through surface analysis techniques and electrochemical methods. Results showed that local adhesion is a typical characteristic for biofilm on surface of Q235 carbon steel in M. f. and mixed consortium media, which induces localized corrosion of Q235 carbon steel. Corrosion rates of Q235 carbon steel in different culture media decrease in the order: rM. f. > rmixed consortium > rT. sp. > rsterile. The evolution of corrosion rate along with time decreases in M. f. medium, and increases then keeps table in both T. sp. and mixed consortium media. Corrosion mechanism of Q235 carbon steel in mixed consortium medium is discussed through analysis of surface morphology and composition, environmental parameter, and electrochemical behavior.



Dissolved organic matter (DOM) exists ubiquitously in environments and plays critical roles in pollutant mitigation, transformation, and organic geochemical cycling. Understanding its properties and environmental behaviors is critically important to develop water treatment processes and environmental remediation strategies. Generalized two-dimensional correlation spectroscopy (2DCOS), which has numerous advantages, including enhancing spectral resolution and discerning specific order of structural change under an external perturbation, could be used as a powerful tool to interpret a wide range of spectroscopic signatures relating to DOM. A suite of spectroscopic signatures, such as UV–vis, fluorescence, infrared, and Raman spectra that can be analyzed by 2DCOS, is able to provide additional structural information hiding behind the conventional one-dimensional spectra. In this article, the most recent advances in 2DCOS applications for analyzing DOM-related environmental processes are reviewed, and the state-of-the-art novel spectroscopic

techniques in 2DCOS are highlighted. Furthermore, the main limitations and requirements of current approaches for exploring DOM-related environmental processes and how these limitations and drawbacks can be addressed are explored. Finally, suggestions and new approaches are proposed to significantly advance the development of 2DCOS in analyzing the properties and behaviors of DOM in natural and engineered environments.


http://www.sciencedirect.com/science/article/pii/S001623611930821X

The shale gas production layer of Wufeng-Longmaxi Formation is characterized by ultra-low water saturation, affecting the reservoir adsorption capacity, self-sealing ability, water phase sealing ability, and the shale gas production. Therefore, we studied the occurrence characteristics and the removal mechanism of residual water in Wufeng-Longmaxi shale of Changning-Weiyuan area using the direct method, i.e., nuclear magnetic resonance (NMR), field emission-scanning electron microscopy (FE-SEM), focused ion beam-scanning electron microscopy (FIB-SEM), µm-CT), and the indirect methods., i.e., N2 adsorption, CO2 adsorption, and mercury intrusion porosimetry (MIP). The results showed that residual water mainly exists in the clay-related inorganic pores. Micropore and mesopore are better for the residue water occurrence, relating to a higher removal rate in the heating process. Distribution of water in micropore, mesopore, and macropore are different: volume filling and surface adsorption are equally same in the micropore, the volume-filled water is gradually absorbed by the surface, and then removed in the mesopore, while the pore water will be absorbed by the surface when the pore volume exceeds a certain value in the macropore. In addition, the residue water is prone to migrate from organic pore to inorganic pore and has a plugging effect on pores in the mesopore especially in the range of 2–10 nm.

Cordero, C., Guglielmetti, A., Bicchi, C., Liberto, E., Baroux, L., Merle, P., Tao, Q., Reichenbach, S.E., 2019. Comprehensive two-dimensional gas chromatography coupled with time of flight mass spectrometry featuring tandem ionization: Challenges and opportunities for accurate fingerprinting studies. Journal of Chromatography A 1597, 132-141.


The capture of volatile patterns from food is a fingerprinting that opens access to a high level of information related to functional variables (origin, processing, shelf-life etc.) and their impact on sample composition and quality. When the focus is on food volatilome, comprehensive two-dimensional gas chromatography combined with time-of-flight mass spectrometry (GC×GC-TOF MS) is undoubtedly the most effective technique to obtain a highly representative fingerprinting.

A recently patented ion source, featuring variable-energy EI, when operated at low energies (10 eV, 12 eV, 14 eV), claims enhanced intensity of structure-indicating ions while minimizing the inherent loss of sensitivity due to low EI energies. The spectral acquisition is done by multiplexing between two ionization energies and generates tandem data streams in a single run.

This study explores the potentials of combined untargeted/targeted (UT) fingerprinting with tandem signals to study the complex volatile metabolome of high quality cocoa.

The quality of the spectra at 70 eV is confirmed by similarity match factors above a fixed threshold (950) while spectral differences between hard (70 eV) and soft (12 eV, 14 eV) ionization are

computed in terms of spectral similarity and signal-to-noise ratio (SNR). Tandem signals are then processed independently and after fusion in a single stream (summed signal) by the UT fingerprinting work-flow; signal characteristics (SNR, detectable 2D peaks, spectral peak intensities) are then computed and adopted to define the best strategy to discriminate and classify samples.

Classification performance, on processed cocoa from four different origins, is validated by cross-comparing results between single ionization channels and fused data streams and considering both targeted and untargeted features. Classification results indicate the potential for superior performances of UT fingerprinting with fused data streams (summed signals), while signal characteristics at low ionization energies not only offer additional elements to better discriminate and/or identify isomeric analytes but also to achieve wider dynamic range of exploration.

Cordier, D., Carrasco, N., 2019. The floatability of aerosols and wave damping on Titan’s seas. Nature Geoscience 12, 315-320.

https://doi.org/10.1038/s41561-019-0344-4

Titan, the enigmatic large moon of Saturn, is unique because it is the only satellite of the solar system that is surrounded by a dense atmosphere. Thick layers of photochemical organic aerosols shroud the surface and sediment to the ground. In polar regions, large lakes and seas of liquid hydrocarbons were discovered by the Cassini–Huygens mission. Aerosols that sediment above the lakes run into a liquid surface in which new interactions can take place. In this paper, we address the question of the first contact between the aerosols and the lakes: do the aerosol particles float or rapidly sink into the lakes? We investigated the possible effects of a floating film or slick formed by this organic material and other products of the atmosphere. We also compared the wave damping effect on Earth's oceans to the Titan counterparts. According to this work, Titan appears to be a much more favourable place for such a damping. By inhibiting the formation of the first ripples, this phenomenon could impede the existence of waves at wavelengths larger than a few centimetres. This effect could explain the remarkable smoothness of the sea surface often noticed in Cassini observations.



Recent studies showed that the presence of dispersed nanoparticles (NPs) can increase the efficiency of polymer flooding. The network structure of polymer/NP hybrid dispersion has a significant impact on oil recovery. In this work, the surface of SiO2 NPs was modified by chemical grafting of octyltriethoxysilane (SiO2-OTES), oleic acid (SiO2-OAA) and stearic acid (SiO2-SAA) in an attempt to stimulate higher degree of interaction with partially hydrolyzed polyacrylamide (HPAM). Thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), and Fourier transform infrared (FTIR) spectroscopy were employed to characterize the modified silica NPs. In addition, ζ-potential, cryo-scanning electron microscopy (cryo-SEM), and linear and nonlinear rheology were used to evaluate the characteristics of the hybrid dispersion of HPAM/unmodified and modified SiO2 NPs. ζ-potential measurements showed that the addition of HPAM improved the colloidal stability of the modified and unmodified SiO2 NPs dispersed in deionized (DI) water. Moreover, the addition of HPAM reduced the size of the NP aggregates by effective steric repulsion. Small and large shear oscillatory deformation results showed that SiO2-OTES NPs improved the HPAM network significantly. Nevertheless, HPAM/NPs network formed with all the different SiO2 NPs severely decreased the intra-cycle shear-thickening behavior of the polymer. Lastly, the addition of 0.2 wt%

SiO2-OTES NPs to the HPAM solution increased the ultimate oil recovery from 71.4% to 75.7% OOIP.

Couturier-Tamburelli, I., 2019. To sink or swim in Titan’s lakes. Nature Geoscience 12, 310-311.

https://doi.org/10.1038/s41561-019-0361-3

Flotation of aerosols as a film on the hydrocarbon lakes of Saturn’s moon Titan may explain the lakes’ stillness, and could influence the atmospheric hydrocarbon cycle.

Cramm, M.A., Chakraborty, A., Li, C., Ruff, S.E., Jørgensen, B.B., Hubert, C.R.J., 2019. Freezing tolerance of thermophilic bacterial endospores in marine sediments. Frontiers in Microbiology 10, 945. doi: 10.3389/fmicb.2019.00945.


Dormant endospores of anaerobic, thermophilic bacteria found in cold marine sediments offer a useful model for studying microbial biogeography, dispersal, and survival. The dormant endospore phenotype confers resistance to unfavourable environmental conditions, allowing dispersal to be isolated and studied independently of other factors such as environmental selection. To study the resilience of thermospores to conditions relevant for survival in extreme cold conditions, their viability following different freezing treatments was tested. Marine sediment was frozen at either -80°C or -20°C for ten days prior to pasteurization and incubation at +50°C for 21 days to assess thermospore viability. Sulfate reduction commenced at +50°C following both freezing pretreatments indicating persistence of thermophilic endospores of sulfate-reducing bacteria. The onset of sulfate reduction at +50°C was delayed in -80°C pretreated microcosms, which exhibited more variability between triplicates, compared to -20°C pretreated microcosms and parallel controls that were not frozen in advance. Microbial communities were evaluated by 16S rRNA gene amplicon sequencing, revealing an increase in the relative sequence abundance of thermophilic endospore-forming Firmicutes in all microcosms. Different freezing pretreatments (-80°C and -20°C) did not appreciably influence the shift in overall bacterial community composition that occurred during the +50°C incubations. Communities that had been frozen prior to +50°C incubation showed an increase in the relative sequence abundance of OTUs affiliated with the class Bacilli, relative to unfrozen controls. These results show that freezing impacts but does not obliterate thermospore populations and their ability to germinate and grow under appropriate conditions. Indeed the majority of the thermospore OTUs detected in this study (21 of 22) could be observed following one or both freezing treatments. These results are important for assessing thermospore viability in frozen samples and following cold exposure such as the very low temperatures that would be encountered during panspermia.



The thermodynamics of metastable empty sI-clathrate hydrates are probed over broad temperature and pressure ranges, 100 ≤ T (K) ≤ 220 and 1 ≤ p (bar) ≤ 5000, respectively, by large-scale simulations and compared with experimental data at 1 bar. The whole p–V–T surface obtained is fitted by the universal form of the Parsafar and Mason equation of state with an accuracy of 99.7–99.9%. Framework deformation brought about by the applied temperature follows a parabolic law, and there is a critical temperature above which the isobaric thermal expansion becomes negative,

ranging from 194.7 K at 1 bar to 166.2 K at 5000 bar. That response to the applied (p, T) field is analyzed in terms of angle and distance descriptors of a classical tetrahedral structure and observed to occur essentially by means of angular alteration for (p, T) > (2000 bar, 200 K). The length of the hydrogen bonds responsible for framework integrity is insensitive to the thermodynamic conditions and its average value is r(O-H)=0.25 nm.

Csank, A.Z., Czimczik, C.I., Xu, X., Welker, J.M., 2019. Seasonal patterns of riverine carbon sources and export in NW Greenland. Journal of Geophysical Research: Biogeosciences 124, 840-856.

https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/2018JG004895

Glacial runoff exports large amounts of carbon (C) to the oceans, but major uncertainty remains regarding sources, seasonality, and magnitude. We apportioned C exported by five rivers from glacial and periglacial sources in northwest Greenland by monitoring discharge, water sources (δ18O), concentration and composition of dissolved organic carbon (DOC), and ages (14C) of DOC and particulate organic C over three summers (2010–2012). We found that particulate organic C (F = 1.0366–0.2506) was generally older than DOC in glacial sourced rivers and likely sourced from the physical erosion of aged C pools. Most exported DOC showed strong seasonal variations in sources and discharge. In summer, mean DOC ages ranged from modern to 4,750 cal years BP (F = 1.0022–0.6291); however, the annual C flux from glacially sourced rivers was dominated by young, plant-derived DOC (F = 0.9667–1.002) exported during the spring freshet. The most aged DOC (F = 0.6891–0.8297) was exported in middle to late summer at lower concentrations and was glacial in origin. Scaled to the whole of Greenland using model-estimated runoff, we estimate a total riverine DOC flux of 0.29% to 0.45% ± 20% Tg C/year. Our flux results indicate that the highest C fluxes occur during the time of year when the majority of C is modern in age. However, higher melt rates from the Greenland ice sheet and longer growing seasons could result in increasing amounts of ancient C from the Greenland ice sheet and from the periglacial landscape to the ocean.



Coastal vegetated ecosystems constitute very productive habitats, characterized by efficient Corg sequestration and long-term preservation in sediments, so they play an important role in climate change mitigation. The temporal evolution of Corg content, stocks and burial rates were evaluated in seagrass and salt marsh habitats in San Quintin Bay (northeast Pacific, Mexico) by using 210Pb-dated sediment cores. Salt marsh cores were characterized by fine-grained sediments, higher salinities, lower terrigenous input and lower mass accumulation rates (MAR: 0.01–0.03 g cm−2 yr−1) than seagrass cores (MAR: 0.02–3.21 g cm−2 yr−1). Accumulation rates in both habitats steadily increased throughout the past century most likely because of soil erosion promoted by land use changes in the surroundings. The Corg stocks were highest in salt marsh cores (12.2–53.6 Mg ha−1 at 10 cm depth; 259–320 Mg ha−1 at 1 m depth) than in seagrass cores (5.7–14.4 Mg ha−1, and 80–98, Mg ha−1, respectively), whereas Corg burial rates were considerably lower in salt marsh (13–60 g m−2 yr−1) than in seagrass (9–144 g m−2 yr−1) habitats, and the temporal variations observed in Corg burial rates were mostly driven by changes in the accumulation rates. The overall Corg stock (485 ± 51 Gg C) for both habitats together was comparable to the carbon emissions of a major city nearby. Our results highlight the need to protect these environments as relevant carbon reservoirs.



Abstract: Peatland ecosystems are generally carbon (C) sinks. However, the role of dissolved organic C (DOC) relative to gaseous fluxes of CO2 and CH4 in the C balance of these ecosystems has not often been studied. Dissolved C fluxes are important for understanding C partitioning within the peatland and the potential C drainage from it. This research was conducted in Burns Bog, a heavily impacted ecosystem near Vancouver, Canada, undergoing ecological restoration efforts by rewetting. Here we present data on (i) ecosystem-scale fluxes of CO2 (net ecosystem exchange, NEE) and CH4 (FCH4) determined by eddy covariance, (ii) evasion fluxes of CO2 and CH4 from the water surface to estimate the role of open water in ecosystem-scale fluxes, and (iii) DOC flux (fDOC) in water draining from the peatland. Our results showed that open water areas inside the footprint were a continual C source, emitting 47.0 ± 2.4 g C·m−2·year−1. DOC export (15.6 g C·m−2·year−1) was significant to the net ecosystem C balance, decreasing the magnitude of the eddy covariance-determined C balance (i.e., NEE + FCH4) of −45.0 ± 16.8 g C·m−2·year−1 by 35%, resulting in a net ecosystem C balance (i.e., NEE + FCH4 + fDOC) of −29.7 ± 17.0 g C·m−2·year−1. Most of this offset occurred during the wetter nongrowing season when gross primary production was low and fDOC was relatively high.

Plain Language Summary: Healthy peatlands can store large amounts of carbon, but disturbance may turn a peatland into a carbon emitter. We studied the amount of carbon entering and leaving a disturbed peatland that has recently undergone ecological restoration by rewetting. We measured climate conditions and ecosystem‐scale CO2 and CH4 fluxes in Burns Bog, a heavily impacted raised bog in the Fraser River Delta, BC, Canada. We also collected water samples and estimated evasion fluxes of CO2 and CH4 from the open water, as well as drainage fluxes of dissolved organic carbon. From these data, we estimated the amount of carbon entering and leaving the ecosystem. We found that open water areas continually emit carbon to the atmosphere, but the ecosystem as a whole is accumulating carbon on an annual basis. Accounting for the dissolved carbon exported by water reduces the estimates of carbon accumulation based on gas fluxes alone. These results have implications for restoration management of peatlands, which mainly consist of raising the water table level, and the role of peatland ecosystems within the context of global climate change.



The exposure for workers handling and recycling offshore drilling waste are previously not described, and given the potential for exposure to hazardous components, there is a need for characterizing this occupational exposure. In this study five plants recycling offshore drilling waste with different techniques were included. Measurements were conducted in both winter and summer to include seasonal exposure variations. Altogether >200 personal air-exposure measurements for oil mist, oil vapor, volatile organic compounds (VOC), hydrogen sulfide (H2S) and solvents were carried out respectively. Microorganisms related to drilling waste were identified in bulk samples and in stationary air measurements from two of the plants. The exposure to oil mist and oil vapor were below 10% of the current Norwegian occupational exposure limits (OEL) for all measured

components. The plants using the Resoil or TCC method had a statistically significant higher exposure to oil vapor than the plant using complete combustion (p-value <0.05). No statistically significant difference was found between the different treatment methods for oil mist. The exposure to solvents was generally low (additive factor < 0.03). Endotoxin measurements done during winter showed a median concentration of 5.4 endotoxin units (EU)/m3. Levels of H2S above the odor threshold of 0.1 ppm were measured at four plants. Both drill mud and slop water contained a high number and diversity of bacteria (2-4 × 104 colony forming unit (CFU)/mL), where a large fraction was Gram-negative species. Some of the identified microorganisms are classified as potentially infectious pathogens for humans and thus might be a hazard to workers.

Dahl, M., Survo, S., Välitalo, P., Kabiersch, G., Alitalo, O.-S., Penttinen, O.-P., Rantalainen, A.-L., 2019. Identification of toxicants from a highly C10–C40-contaminated sediment influenced by the wood industry: Petroleum hydrocarbons or biogenic organic compounds? Environmental Toxicology and Chemistry 38, 936-946.

https://doi.org/10.1002/etc.4380

Sediment from a log pond located in south Finland contained 15 000 to 50 000 mg/kg dry weight of C10–C40 hydrocarbons. It was unclear whether they originated from the hydraulic fluid of the log hoist or the wood extractives. In the present study, methods of effect‐directed analysis were used for the identification of toxicants. A combination of fractionation, biotesting, and chemical analyses revealed that the key toxicant of log pond sediment was retene, a dialkyl‐substituted phenanthrene derived from wood resin acids. In addition, the most toxic fraction included 3 other wood‐originated diterpenic compounds. Typical wood extractives such as sesquiterpenes and odd–carbon number alkanes in the range C21–C33 were identified in the fraction, which showed minor genotoxic potency. The most polar fraction contained triterpenes and showed estrogenic activity. No evidence for the presence of hydraulic fluid in sediment was found. The study also indicated that in cases where the organic matter content of sediment or soil is high, using the results of standard mineral oil analysis in risk management can lead to incorrect actions because standard methods do not differentiate petroleum hydrocarbons from biogenic hydrocarbons.

Dall'Osto, M., Airs, R., Beale, R., Cree, C., Fitzsimons, M.F., Beddows, D.C.S., Harrison, R.M., Ceburnis, D., O'Dowd, C., Rinaldi, M., Paglione, M., Nenes, A., Decesari, S., Simo, R., 2019. Simultaneous detection of alkylamines in the surface ocean and atmosphere of the Antarctic sympagic environment. ACS Earth and Space Chemistry 3, 854-862.


Measurements of alkylamines from seawater and atmospheric samples collected simultaneously across the Antarctic Peninsula, South Orkney and South Georgia Islands are reported. Concentrations of mono-, di- and trimethylamine (MMA, DMA and TMA, respectively), and their precursors, the quarternary amines glycine betaine and choline, were enhanced in sympagic sea water samples relative to ice-devoid pelagic ones, suggesting the microbiota of sea ice and sea ice-influenced ocean is a major source of these compounds. Primary sea-spray aerosol particles artificially generated by bubbling seawater samples were investigated by Aerosol Time-Of-Flight Mass Spectrometry (ATOFMS) of single particles; their mixing state indicated that alkylamines were aerosolized with sea spray from dissolved and particulate organic nitrogen pools. Despite this unequivocal sea spray-associated source of alkylamines, ATOFMS analyses of ambient aerosols in the sympagic region indicated that the majority (75-89 %) of aerosol alkylamines were of secondary origin, i.e., incorporated into the aerosol after gaseous air-sea exchange. These findings show that sympagic

seawater properties are a source of alkylamines influencing the biogenic aerosol fluxed from the ocean into the boundary layer; these organic nitrogen compounds should be considered when assessing secondary aerosol formation processes in Antarctica.

Dan, S.F., Liu, S.-M., Yang, B., Udoh, E.C., Umoh, U., Ewa-Oboho, I., 2019. Geochemical discrimination of bulk organic matter in surface sediments of the Cross River estuary system and adjacent shelf, South East Nigeria (West Africa). Science of The Total Environment 678, 351-368.


Knowledge of the sources, distribution and fate of organic matter (OM) in estuarine and adjacent shelf sediments are important for the understanding of the global biogeochemical cycles. Bulk organic carbon (C-org), total nitrogen (TN), biogenic silica (BSi), stable carbon (δ13C-org) and nitrogen (δ15N) isotopes, and sediment grain sizes were measured to study the spatial distributions and sources of sediment OM in the Cross River estuary system (CRES) and adjacent shelf. Surface sediments in the CRES were composed of clayey silt and sandy silt, while the adjacent shelf sediments were mainly silty sand. The range of the studied parameters was −28.79‰ to −22.20‰ for δ13C-org, −1.32‰–6.31‰ for δ15N, 6.7–29.2 for C-org/N ratios, 0.08%–0.33% for TN, 0.24‰–0.74‰ for BSi, and 0.47%–5.28% for C-org, and their spatial distributions showed a general decreasing trend in both the terrestrial and estuarine OM from the riverine regions to the adjacent shelf. Based on the three-end-member mixing model using the δ13C and δ15N isotopic values, ~58.01 ± 15.32% of sediment OM are derived from terrestrial sources dominated by C3 vascular plants, while ~26.34 ± 9.71% are attributed to estuarine sources dominated by aquatic macrophytes, and ~15.65 ± 12.37% for marine plankton source. Other sources of OM identified included soils underlain C3 vascular plants and agricultural farms enriched with N, sewage, and petroleum hydrocarbons. The relationship between C-org vs. BSi, and the atomic BSi/Corg ratios suggested that diatoms also play an important role in OM sequestration in surface sediments of the CRES and adjacent shelf. The correlations of the δ13C-org and δ15N isotopic values vs. C-org/N ratios resulted in scatter plots, indicating that the distributions of sediment OM in the CRES and adjacent shelf are influenced by post depositional processes, fixed inorganic N adsorbed on fine-grained sediments, microbial degradation, as well as sediment grain size.

Dance, T., LaForce, T., Glubokovskikh, S., Ennis-King, J., Pevzner, R., 2019. Illuminating the geology: Post-injection reservoir characterisation of the CO2CRC Otway site. International Journal of Greenhouse Gas Control 86, 146-157.


Proper site characterisation is vital in the planning stages of a CO2 storage project; but we can also learn a good deal about the reservoir once the injection is underway or has been completed. During CO2CRC Otway Project Stage 2C, sources of valuable information about storage performance have been generated as a consequence of the staged injection of 15,000 t of CO2 rich gas, as well as observations from time-lapse seismic surveys and well monitoring data. Now that injection has ceased for Stage 2C, the geological model is compared against field observations for the period spanning injection and 23 months after injection ended. The post-injection reservoir characterisation has proven important to refine the static and dynamic models for future field development and added assurance about the long-term stabilisation of the CO2 plume. The south-eastern progress of plume development, as seen on the time-lapse seismic data, has led to a review of the structural interpretation and horizon-fault geometry represented in the models. The developing plume has illuminated the extent of splay faults previously unresolved on the baseline seismic data. Saturation

profiles interpreted from pulsed-neutron logs at the injection and observation wells show a preference for higher saturations occurring in high permeability distributary channels penetrated by each of the wells. This has reduced the uncertainty in predicting connectivity of this facies between the wells. The pressure data from numerous injection events has been used to refine the characterisation of the average horizontal permeability of the reservoir zone, and the vertical permeability of the intra-formational seal. It has also been used to infer near-field bounding conditions of the interior splay fault, which in turn improves our understanding of containment at the site.

Darko, E., Thurbide, K.B., 2019. Dynamic control of gas chromatographic selectivity during the analysis of organic bases. Analytical Chemistry 91, 6682-6688.


A novel method for controlling selectivity during the gas chromatographic (GC) analysis of organic bases is presented. The technique employs tandem stainless steel capillary columns, each coated with a pH adjusted water stationary phase. The first is a 0.5 m trap column coated with a pH 2.2 phase, while the second is an 11 m analytical column coated with a pH 11.4 phase. The first column traps basic analytes from injected samples, while the remaining components continue to elute and separate. Then, upon injection of a volatile aqueous ammonia solution, the basic analytes are released as desired to the analytical column where they are separated and analyzed. Separations are quite reproducible and demonstrate an average RSD of 1.2% for analyte retention times in consecutive trials. Using this approach, the retention of such analytes can be readily controlled and they can be held in the system for periods of up to 1 h without significant erosion of peak shape. As such, it can provide considerable control over analyte selectivity and resolution compared to conventional separations. Further, by employing a third conventional GC column to the series, both traditional hydrocarbon and enhanced organic base separations can be performed. The method is applied to the analysis of complex mixtures, such as gasoline, and much less matrix interference is observed as a result. The findings indicate that this approach could be a useful alternative for analyzing such samples.

Dauner, A.L.L., Mollenhauer, G., Bícego, M.C., de Souza, M.M., Nagai, R.H., Figueira, R.C.L., de Mahiques, M.M., Sousa, S.H.d.M.e., Martins, C.C., 2019. Multi-proxy reconstruction of sea surface and subsurface temperatures in the western South Atlantic over the last ∼75 kyr. Quaternary Science Reviews 215, 22-34.


Millennial-scale oscillations are known to be important in the climatic evolution of the Atlantic basin, but which internal processes originates these oscillations are still uncertain. In this study, we investigated how the Greenland and Antarctic climates affect the SW Atlantic through basin-wide oceanographic features (such as the NADW formation and the Agulhas leakage). We reconstructed sea surface and subsurface temperatures (SST and subT) using three lipid-based biomarker proxies (UK’37, TEX86 and LDI indexes) from a sediment core (NAP 63-1) retrieved from the SW Atlantic slope (24.8°S, 44.3°W). This location allowed us to evaluate the temperature oscillations of the Brazil Current without any terrigenous or upwelling-derived biases. Both TEX86-based and LDI-based estimates represent the mean annual SST, while the UK’37-based estimates represent the subT (around 30 m water depth). The periods with the most well-mixed water column were observed during intervals of cooling orbital trends due to the time required to transfer the surface cooling to the subsurface. The temperature reconstructions showed a general colder MIS 3 when compared to the MIS 4. They also showed evidence of a late response to deglaciation, with its onset in the SW

Atlantic occurring in the middle of the Last Glacial Maximum. Based on these reconstructions, the NAP 63-1 SST orbital-scale trend seems to be linked to the Antarctic climate, influenced by local insolation changes. These temperature records also presented a clear millennial periodicity around 8 kyr. On this timescale, the millennial oscillations in the SW Atlantic's SST are likely linked to the NADW formation.

Davies, E.J., Dunnebier, D.A.E., Johansen, Ø., Masutani, S., Nagamine, I., Brandvik, P.J., 2019. Shedding from chemically-treated oil droplets rising in seawater. Marine Pollution Bulletin 143, 256-263.


The degree to which droplet shedding (tip-streaming) can modify the size of rising oil droplets has been a topic of growing interest in relation to subsea dispersant injection. We present an experimental and numerical approach predicting oil droplet shedding, covering a wide range of viscosities and interfacial tensions.

Shedding was observed within a specific range of droplet sizes when the oil viscosity is sufficiently high and the IFT is sufficiently low. The affected droplets are observed to reduce in size, as smaller satellite droplets are shed, until the parent droplet reaches a stable size.

Shedding of smaller droplets is related to the viscosity-dominated modified capillary number (Ca′), especially for low dispersant dosages recommended for subsea dispersant injection. This, in combination with the IFT-dominated Weber number (We), characterise droplets into three possible states: 1) stable (Ca′ < 0.21 & We<12); 2) tip-streaming (Ca′ > 0.21 & We<12); 3) unstable and subject to total breakup (We>12).

Daye, M., Higgins, J., Bosak, T., 2019. Formation of ordered dolomite in anaerobic photosynthetic biofilms. Geology 47, 509-512.

https://doi.org/10.1130/G45821.1

Dolomite enabled the preservation of fine microbial textures in some Archean and Proterozoic marine microbialites, but has rarely done so during the Phanerozoic. Here, we report precipitation of dolomite in anoxygenic photosynthetic biofilms grown under chemical conditions relevant for Archean seawater. Ordered dolomite nucleates primarily on the surfaces of photosynthetic cells when manganese(II) is present, and nanocrystals of disordered dolomite form on exopolymeric substances in microbial cultures grown either in the dark or without manganese. Dolomite nucleation and maturation on different surfaces in photosynthetically active cultures amended with 0.1–1 mM manganese(II) enables the preservation of biofilm textures at scales larger than individual microbial cells. This provides a new model for the preservation of microbial textures by dolomite before the oxygenation of the oceanic photic zone.

Dean, J.F., 2019. Groundwater dependent ecosystems in arid zones can use ancient subterranean carbon as an energy source in the local food web. Journal of Geophysical Research: Biogeosciences 124, 733-736.

https://doi.org/10.1029/2019JG005089

Abstract: Groundwater dependent ecosystems (GDEs) are defined by their reliance on subterranean water resources, but GDE food webs may also depend on it as an energy source. Mazumder et al. (2019, https://doi.org/10.1029/2018JG004925), show a clear dependency of a local GDE food web on very old, potentially geological, carbon sourced from palaeo‐groundwater discharge in the arid Great Artesian Basin in Australia. These findings support the emerging paradigm that ancient groundwater carbon is an important component of inland water carbon cycling and contemporary ecosystem functioning. Future work is needed to determine what proportion of total GDE energy needs are derived from groundwater carbon across a range of geological and hydroclimatic settings.

Plain Language Summary: Many arid ecosystems rely on groundwater for their water needs. A new study in the arid zone of Australia shows the incorporation of ancient carbon into living aquatic species in these ecosystems. This suggests that present‐day ecosystems may rely on both water and carbon resources generated thousands of years ago when the prevailing environmental conditions were significantly different than today.

Deininger, A., Frigstad, H., 2019. Reevaluating the role of organic matter sources for coastal eutrophication, oligotrophication, and ecosystem health. Frontiers in Marine Science 6, 210. doi: 10.3389/fmars.2019.00210.

https://www.frontiersin.org/article/10.3389/fmars.2019.00210

Organic matter (OM) in aquatic systems is either produced internally (autochthonous OM) or delivered from the terrestrial environment (ter-OM). For eutrophication (or the reverse – oligotrophication), the amount of autochthonous OM plays a key role for coastal ecosystem health. However, the influence of ter-OM on eutrophication or oligotrophication processes of coastal ecosystems is largely unclear. Therefore, ter-OM, or ter-OM proxies are currently not included in most policies or monitoring programs on eutrophication. Nevertheless, ter-OM is increasingly recognized as a strong driver of aquatic productivity: By influencing underwater light conditions and nutrient- and carbon availability, increased ter-OM input may shift systems from autotrophic towards heterotrophic production, but also alter the interactions between benthic and pelagic habitats. Thus, by changing baseline conditions in coastal zones, ongoing and predicted changes in inputs of ter-OM due to climate change (e.g. in precipitation) and anthropogenic activities (e.g. reduced sulfate deposition, damming, coastal erosion) may strongly modify eutrophication symptoms within affected ecosystems, but also hinder recovery from eutrophication following a reduction in nutrient loadings (i.e. oligotrophication). In this review, we aim to shed light upon the role of ter-OM for coastal eutrophication and oligotrophication processes and ecosystem health. Specifically, we (1) discuss the theoretical interactions between ter-OM and eutrophication and oligotrophication processes in coastal waters, (2) present global case studies where altered ter-OM supply to coastal ecosystems has shifted baseline conditions, with implications for eutrophication and oligotrophication processes, and (3) provide an outlook and recommendations for the future management of coastal zones given changes in ter-OM input. We conclude that it is essential to include and target all OM sources (i.e. also ter-OM) in monitoring programs to better understand the consequences of both eutrophication and oligotrophication processes on coastal ecosystems. Our review strongly urges to include ter-OM, or ter-OM proxies in eutrophication monitoring and policies to safeguard coastal ecosystem health also under changing climatic conditions and globally increasing anthropogenic perturbations of coastal ecosystems.

Delile, H., Pleuger, E., Blichert-Toft, J., Goiran, J.-P., Fagel, N., Gadhoum, A., Abichou, A., Ben Jerbania, I., Fentress, E., Wilson, A.I., 2019. Economic resilience of Carthage during the Punic Wars:

Insights from sediments of the Medjerda delta around Utica (Tunisia). Proceedings of the National Academy of Sciences 116, 9764-9769.


Significance: How do we explain the exceptional economic resilience for more than a century and a half of the Carthaginian civilization during the Punic Wars? Based on eight deep cores taken in the Medjerda delta around the city of Utica in Tunisia, we show that the sustainable retreat of Carthage into its hinterland during this period of warfare provided the metal resources whose exploitation by the Carthaginians was sufficient to resist the Romans for so long. The earliest phase of mining activity recorded in the Utica sediments occurred during the Greco-Punic Wars (480–307 BC) and is coeval with the first minting of Punic coins at Carthage, from which point on the Carthaginian economy became increasingly monetized.

Abstract: While the Punic Wars (264–146 BC) have been the subject of numerous studies, generally focused on their most sensational aspects (major battles, techniques of warfare, geopolitical strategies, etc.), curiously, the exceptional economic resilience of the Carthaginians in the face of successive defeats, loss of mining territory, and the imposition of war reparations has attracted hardly any attention. Here, we address this issue using a newly developed powerful tracer in geoarchaeology, that of Pb isotopes applied to paleopollution. We measured the Pb isotopic compositions of a well-dated suite of eight deep cores taken in the Medjerda delta around the city of Utica. The data provide robust evidence of ancient lead–silver mining in Tunisia and lay out a chronology for its exploitation, which appears to follow the main periods of geopolitical instability at the time: the Greco-Punic Wars (480–307 BC) and the Punic Wars (264–146 BC). During the last conflict, the data further suggest that Carthage was still able to pay indemnities and fund armies despite the loss of its traditional silver sources in the Mediterranean. This work shows that the mining of Tunisian metalliferous ores between the second half of the fourth and the beginning of the third century BC contributed to the emergence of Punic coinage and the development of the Carthaginian economy.

Dennis, P.F., Myhill, D.J., Marca, A., Kirk, R., 2019. Clumped isotope evidence for episodic, rapid flow of fluids in a mineralized fault system in the Peak District, UK. Journal of the Geological Society 176, 447-461.

https://jgs.lyellcollection.org/content/176/3/447.abstract

We have used clumped isotope thermometry to study a fault-hosted hydrothermal calcite vein associated with the Mississippi Valley Type (MVT) mineralization on the Derbyshire Platform in the southern Pennines, UK. This is the first published dataset obtained using a new mass spectrometer, MIRA, optimized for clumped isotope analysis and an associated clumped isotope–temperature calibration. We analysed multiple generations of vein growth at high spatial resolution in two transects across the vein. The vein grew episodically at temperatures between 40 and 100°C. We interpret each episode of growth as being associated with an increasing flux of formation waters from deep sedimentary basins next to the mineralized platform and an accompanying increase in the precipitation temperatures. Heat is conserved in the fluid as it ascends along the fault surface and, thus, flow must have been fast and restricted to short-lived pulses. The flux could have been driven by high pore pressures associated with rapid sedimentation, hydrocarbon generation and diagenesis in the basinal facies of the Visean Bowland–Hodder group. Natural hydraulic fracturing of shale units and failure of capillary seals, possibly triggered by uplift, allowed the release of fluids into aquifers within the sediment pile. The transmission of high pore fluid pressures from the shales to the fault zone, aided by the compressibility of the gas phase in two-phase pore fluids, may have resulted in

fault rupture, accompanied by enhanced fracture permeability and rapid fluid flow. Vein growth ceased as pore pressures dissipated. Such behaviour is closely related to a seismic valve type model for mineralization.Supplementary material: Details of the methods and equipment are available at https://dx.doi.org/10.6084/m9.figshare.3808329.v9

Dinelli, B.M., Puertas, M.L., Fabiano, F., Adriani, A., Moriconi, M.L., Funke, B., García-Comas, M., Oliva, F., D'Aversa, E., Filacchione, G., 2019. Climatology of CH4, HCN and C2H2 in Titan's upper atmosphere from Cassini/VIMS observations. Icarus 331, 83-97.


The Visual and Infrared Mapping Spectrometer (VIMS) measurements of non-Local Thermodinamic Equilibrium (non-LTE) emissions of CH4, HCN and C2H2 in the near-infrared represent a dataset with unique coverage to study Titan's upper atmosphere in the altitude range from 500 to 1000 km. This region is the key to a better understanding of the middle atmosphere circulation. The assessment of the latitudinal and seasonal variations in the distributions of HCN and C2H2 could give important hints about it and complement the Composite InfraRed Spectrometer (CIRS) observations, that target the atmosphere below 500 km. The measurement of CH4 and HCN above 900 km can also help in understanding the Ion and Neutral Mass Spectrometer (INMS) observations near and above 1000 km. We have analysed the VIMS daytime spectra in the 2.9–3.4 μm region measured from 2004 to 2012 that span from the mid-northern winter through mid-northern spring Titan seasons. The measurements exhibit very strong non-LTE emissions of CH4, HCN and C2H2. Non-LTE vibrational temperatures have been calculated for the emitting levels of the three molecules, and have been used in the inversion of their abundances in the 500–1100 km region. The retrieved abundances have been averaged in latitudinal bins and in two seasons: north hemisphere winter (2004–2009) and north hemisphere early spring (2010−2012). The C2H2 average profile, retrieved for the first time from VIMS measurements, shows good agreement with UltraViolet Imaging Spectrograph (UVIS) measurements below 850 km, while higher values are found above that altitude. The HCN volume mixing ratio (VMR) shows an enhancement at the north pole during winter at all altitudes (from ∼700 km up to near 1000 km) and at the north and south poles during spring below 900 km. Also, the average C2H2 abundance is larger at both poles during spring below 800 km, while no significant variation is seen during winter. For CH4 we found enhancements above 800 km at the north pole during winter and at both poles during spring. Our results suggest that the middle atmosphere circulation on Titan extends well above the 500 km level, up to 750–800 km or even higher if we assume that the CH4 concentration above 800 km is mainly controlled by the circulation. The behavior of CH4 at the winter pole above 800 km is in line with the strong zonal winds suggested to explain INMS observations, although it can also be explained by the slower photo-dissociation occurring during polar winter. Despite the poor statistic at the polar regions, our results represent a unique dataset that could help to improve our understanding of Titan's atmosphere above 500 km.

Ding, X., Qu, J., Imin, A., Zha, M., Su, Y., Jiang, Z., Jiang, H., 2019. Organic matter origin and accumulation in tuffaceous shale of the lower Permian Lucaogou Formation, Jimsar Sag. Journal of Petroleum Science and Engineering 179, 696-706.


The Jimsar Sag is an important shale oil exploration target area in the Junggar Basin, northwestern China. The lower Permian Lucaogou Formation, with a thickness of 200–300 m, is composed of thin tuffite, tuffaceous dolomite, mudstone and siltstone, and is the primary exploration target. A comprehensive analysis is conducted on the bulk and molecular geochemical characteristics of the

tuffaceous shale, to define the organic matter origin, depositional environment and organic matter accumulation. The key features of the tuffaceous shale extracts are short-to long-chain n-alkanes, a range of Pr/Ph ratio values (0.80–1.42), a relatively high content of C29 steranes and a moderate content of gammacerane, showing that the redox state ranged from oxic to anoxic and that the water salinity conditions varied from fresh to brackish. And the high content of cyanobacteria is the primary cause of the high abundance of β-carotane and C29 sterane. It appears that volcanic ash did not change the redox condition of depositional environment. Considering that volcanic ash-bearing sediments usually have relatively high β-carotane and C29 sterane content, and previous studies have pointed out that volcanic ash can stimulate phytoplankton and promote productivity in modern sediments, we could speculated volcanic ash may release mineral ions such as iron, and then stimulated cyanobacteria, which was the main cause of organic matter accumulation in the tuffaceous shale of the Jimsar Sag.

Dodge, L.A., Kalinoski, R.M., Das, L., Bursavich, J., Muley, P., Boldor, D., Shi, J., 2019. Sequential extraction and characterization of lignin-derived compounds from thermochemically processed biorefinery lignins. Energy & Fuels 33, 4322-4330.


As the most abundant source of renewable aromatic compounds on the planet, lignin is an attractive feedstock for producing a range of chemicals and products that are currently derived from petroleum. Despite its great potential, separation of lignin depolymerization products remains one of the main obstacles toward cost-effective lignin valorization. Two lignin-rich streams, residues from enzymatic hydrolysis of the dilute acid and alkaline-pretreated corn stover, were depolymerized via pyrolysis using induction heating and catalytic transfer hydrogenolysis (CTH), respectively. Differences in phenolic compounds from gas chromatography–mass spectrometry and gel permeation chromatography analyses suggest that both pretreatment conditions and lignin depolymerization methods affected the product distribution. CTH lignin oils contain less polar compounds as compared to pyrolysis lignin oils, probably due to saturation of the derived compounds as a result of the reductive chemistry. The resulting liquid oils were subjected to sequential liquid–liquid extraction using a series of solvents with different polarities: hexane, petroleum ether, chloroform, and ethyl acetate. Sequential extraction fractionated lignin-derived oil into groups of different compounds depending on the solvent polarities. This study provides a better understanding of how the lignin source and processing method affect the depolymerization products and provides a possible way to fractionate lignin-derived compounds.

Dong, L., Han, S., Yu, W., Lei, Z., Kang, S., Zhang, K., Yan, J., Li, Z., Shui, H., Wang, Z., Ren, S., Pan, C., 2019. Effect of volatile reactions on the yield and quality of tar from pyrolysis of Shenhua bituminous coal. Journal of Analytical and Applied Pyrolysis 140, 321-330.


Pyrolysis was an important route for coal conversion and also the fundamental for clean and efficient utilization of coal. As an important product of pyrolysis, coal tar can be used as the raw material for producing premium liquid fuels and high value-added chemicals (benzene-toluene-xylene, naphthalene, phenols, etc.). The products’ distribution and quality were significantly affected by the secondary reaction of volatiles. In this work, Shenhua bituminous coal was pyrolyzed with a two-stage reactor at a relatively low temperature, and the released volatiles underwent secondary reactions at various temperatures and residence time. The yields and quality of coal tar were characterized by gas chromatography–mass spectroscopy (GC–MS) and Fourier transformed infrared spectroscopy

(FTIR). The results showed that secondary volatile reactions decrease tar yield but increase gas and coke yield. The volatile reaction results in a decrease in the content of aliphatics and phenols, and an increase in the content of arenes and polar compounds. The volatile reaction includes the following reactions: dehydroxylation, deoxygenation, cleavage of long chain aliphatic structures into short ones, and condensation of aromatic clusters, etc. The higher heating rate of pyrolysis reduces the content of aliphatic and polar compounds while increases that of arenes and phenols in the light tar (HS).

Dong, T., He, S., Chen, M., Hou, Y., Guo, X., Wei, C., Han, Y., Yang, R., 2019. Quartz types and origins in the paleozoic Wufeng-Longmaxi Formations, Eastern Sichuan Basin, China: Implications for porosity preservation in shale reservoirs. Marine and Petroleum Geology 106, 62-73.


Quartz in shales has been demonstrated to exert a significant effect on shale gas production by influencing rock mechanical behavior and reservoir porosity; however, quartz types and origins in shales are complicated and challenging to study due to their fine-grained nature. In this study, we propose combining thin section images, scanning electron microscopy (SEM) images, energy dispersive spectroscopy (EDS) maps, cathodoluminescence (CL) images and geochemical data to investigate quartz types and origins in shale formations. Shale samples from the Ordovician Wufeng-Silurian Longmaxi Formations, Eastern Sichuan Basin, China were used to study quartz types, origins and the effect of quartz cementation on porosity development.

Samples from the Wufeng-Longmaxi Formations have TOC contents in the range of 0.5–4.7 wt%, averaging 2.7 wt%, and are currently in the thermally overmature stage. Five types of quartz, including silt-size detrital quartz, siliceous skeletal fragments, quartz overgrowth, clay matrix-dispersed microquartz, and aggregates of euhedral quartz, were identified. The ternary diagram of Fe–Al–Mn, the cross-plot of SiO2 versus Zr, and the cross-plot of Si versus Al suggest that the dissolution and reprecipitation of siliceous skeletons may provide the major source of silica for quartz cementation in the lower part of the Wufeng-Longmaxi Formations, and released silica as a result of smectite to illite transformation is also important for authigenic quartz formation in the upper part of the Wufeng-Longmaxi Formations. Our SEM images suggest that the rigid framework formed by quartz cementation not only prevents primary interparticle pores from compaction but also favors the generation of organic matter-associated pores.

Droppo, I.G., di Cenzo, P., Parrott, J., Power, J., 2019. The Alberta oil sands eroded bitumen/sediment transitional journey: Influence on sediment transport dynamics, PAH signatures and toxicological effect. Science of The Total Environment 677, 718-731.


This paper investigated the sediment/contaminant continuum of bitumen containing sediment, from eroded exposed natural bitumen outcrops to river depositional zone, in order to improve our understanding of the transitional sediment, chemistry and toxicological influence on aquatic health. To achieve this aim, we linked a rainfall simulator with an annular flume to allow for connectivity between terrestrial erosion to stream flow. Bulk sediments were collected from the minable McMurray Formation (MF) on the Ells (EL) and Steepbank (STB) Rivers and from the Clearwater Formation (CF) on the STB.

All plots generated similar washoff rates (~25 L hr−1) and fine eroded sediment (d50 = 5 μm) regardless of strata. The CF generated the highest total eroded sediment (TES) followed by EL-MF and STB-

MF. The STB-MF generated up to three orders of magnitude lower TES than the STB-CF. The EL generated the highest PAH concentrations, however, when normalizing by TES mass delivered to the flume, STB-MF PAH was one to two orders of magnitude higher per unit mass than EL-MF. The TES concentrations were inversely proportional to the degree of bitumen within the sediment (STB-MF > EL-MF > STB-CF). Once the TES was suspended in the flume, there was a change in the dominant PAH for most classes [e.g., Dibenzothiophenes C4 (parent material) to a C3 (TES)]. Further, no flocculation and the buoyant properties of the TES suggested that the sediment and associated PAHs may travel long distances. The EL-MF proved to be the most toxic to fathead minnow embryo survival due principally to the high PAH concentrations and sediment loads. The CF exhibited no toxicological effect. This work has shown the importance of assessing sediment/contaminant characteristics over the continuum (terrestrial erosion/washoff to river deposition) in order to support basin wide management strategies for the protection of aquatic health.

Du, A., Alemseged, Z., 2019. Temporal evidence shows Australopithecus sediba is unlikely to be the ancestor of Homo. Science Advances 5, Article eaav9038.

http://advances.sciencemag.org/content/5/5/eaav9038.abstract

Understanding the emergence of the genus Homo is a pressing problem in the study of human origins. Australopithecus sediba has recently been proposed as the ancestral species of Homo, although it postdates earliest Homo by 800,000 years. Here, we use probability models to demonstrate that observing an ancestor’s fossil horizon that is at least 800,000 years younger than the descendant’s fossil horizon is unlikely (about 0.09% on average). We corroborate these results by searching the literature and finding that within pairs of purported hominin ancestor–descendant species, in only one case did the first-discovered fossil in the ancestor postdate that from the descendant, and the age difference between these fossils was much less than the difference observed between A. sediba and earliest Homo. Together, these results suggest it is highly unlikely that A. sediba is ancestral to Homo, and the most viable candidate ancestral species remains Australopithecus afarensis.


https://doi.org/10.1080/10916466.2019.1602637

Soluble organic matter (SOM) content, group composition and gas chromatography of mud source rock of the Paleogene ranged 1000 m∼5000 m in Dongying Sag were analyzed. The results show that 3500 m is a conversion boundary for SOM. Under this conversion boundary, SOM has a significant role transformation as in depth less than 3500 m, SOM is the hydrocarbon product but in depth deeper than 3500 m, SOM mainly is the hydrocarbon precursor, and the resins play a major role in hydrocarbon generation.



Transformation of pore and fracture structure of coals with supercritical CO2 (scCO2) –H2O is a key to CO2 injection and CH4 production efficiencies during the CO2 enhanced coalbed methane process. To study the transformation of pores and fractures in the coals with CO2, two reservoir conditions, which simulate1000m (45 °C, 10 MPa) and 2000 m (80 °C, 20 MPa) depths, are applied to four types

of high metamorphic coals from Qinshui Basin to study the influences of temperature and pressure on pore volume and pore sized distribution change. Nuclear magnetic resonance, high pressure mercury intrusion, X-ray CT scanning and permeability experiments are performed and the effects of scCO2 on coal permeability and the influencing factors are discussed. The results show that scCO2-H2O has a positive effect on the improvement on the pore fracture system. It could add or expand pores and fractures, leading to the increase in pore number, porosity, pore volume, pore specific surface area, connected pore volume, and pore throat number. And then, increased the permeability which had a positive correlation with the experimental temperature and pressure. The growth of permeability could be as high as 114.10 times, and it was higher in horizontal to bedding direction than that of the vertical to bedding direction. Coal expansion could lead to the addition and enlargement of micro-fractures and enhance the connectivity between seepage pores and fractures. Mineral dissolution could lead to the formation of a large number of effectively connected and non-effectively connected pores, especially the latter, which was positively correlated with simulated temperature and pressure. In addition, the effectively connected pores tend to develop in vertical original micro-fractures. Moreover, the more complete the reaction is, the more favorable it is to increase the pore volume of fractures.

Dunne, J., Chapman, A., Blinkhorn, P., Evershed, R.P., 2019. Reconciling organic residue analysis, faunal, archaeobotanical and historical records: Diet and the medieval peasant at West Cotton, Raunds, Northamptonshire. Journal of Archaeological Science 107, 58-70.


Information on medieval diet and subsistence practices has traditionally been compiled from a combination of documentary sources, faunal and archaeobotanical assemblages, together with other information gained from archaeological excavations. Much is known of high status medieval dietary practices but less about what foodstuffs the medieval peasantry consumed. Here, we examine the everyday dietary practices of people living in a small medieval manor and associated hamlet at West Cotton, Raunds, Northamptonshire. For the first time, a combined molecular and isotopic approach on absorbed residues, from the substantial pottery assemblage covering a period of around 500 years, was utilised to integrate information on the commodities processed in the vessels, together with detail from the faunal assemblage, archaeobotanical, archaeological and documentary information relating to the site. Lipid residue results from the pottery, mainly jars, identified the importance of ruminant carcass products and leafy vegetables, likely used to prepare the stews or potages known to be the mainstay of the medieval diet, and confirmed by the dominance of sheep and cattle in the faunal assemblage. Around one quarter of the vessels were used to process solely dairy products and some evidence of porcine product processing was found, although this may be under-represented at the site. In brief, this project provided a unique opportunity to address questions of diet and animal husbandry by medieval peasants and helped illustrate agricultural production and consumption in the middle ages.

Duran, J.A., Casas, Y.A., Xiang, L., Zhang, L., Zeng, H., Yarranton, H.W., 2019. Nature of asphaltene aggregates. Energy & Fuels 33, 3694-3710.


The size and fractal dimension of asphaltene aggregates were investigated for two Western Canadian bitumens diluted with n-heptane at concentrations above the onset of precipitation. Asphaltene aggregate size distributions were measured over time using focused beam reflectance and micrographic methods in a series of batch experiments at different n-heptane contents and shear rates.

The fractal dimensions of the aggregates were determined from the volume of the settled aggregates. The asphaltenes formed approximately log-normal size distributions with volume mean diameters of tens to hundreds of micrometers, depending mainly upon the n-heptane content. The distributions were established in less time than the first measurement could be obtained (about 30 s) and changed relatively little afterward. The average aggregate size increased with an increasing n-heptane content but reached a plateau value at 70–80 wt % n-heptane. The fractal dimension reached a maximum at a similar n-heptane content. Micrographic images and fractal dimensions indicated that, near the onset of precipitation, compact linear and planar aggregate structures dominated. At higher n-heptane contents up to approximately 75 wt % n-heptane, the aggregates remained compact but became more three-dimensional. At higher n-heptane contents, larger, looser structures were formed that could be broken under sufficient shear but did not reaggregate. The results were consistent with simultaneous nucleation, growth, and flocculation processes, where the precipitating material was initially sticky but lost its stickiness over time. The loss in stickiness was confirmed with surface force adhesion measurements.

Duval, J., Colas, C., Bonnet, P., Lesellier, E., 2019. Hyphenation of ultra-high performance supercritical fluid chromatography with atmospheric pressure chemical ionisation high resolution mass spectrometry: Part 2. Study of chromatographic and mass spectrometry parameters for the analysis of natural non-polar compounds. Journal of Chromatography A 1596, 199-208.


An analytical method based on Ultra-High-Performance Sub/Supercritical Fluid Chromatography (UHPSFC) coupled with High-Resolution Mass Spectrometry (HR-MS) equipped with an Atmospheric Pressure Chemical Ionisation source (APCI-Q-TOF-HRMS) was developed for the screening of various compounds in oily samples. The hyphenation was achieved using a hybrid UHPSFC system for the vegetable oil analysis, mainly composed of fatty acids, diacylglycerols, triacylglycerols but containing also some minor bioactive compounds. No split was used with this ionisation source in this optimized configuration, allowing the introduction of all compounds in the mass spectrometer, ensuring a better sensitivity. This configuration is preserving peak shapes and efficiency because the dead volume of this interface is optimized by the supplier for the hyphenation with open cell detectors such as Evaporative Light Scattering Detector (ELSD) or MS detectors. The influence of analytical conditions (UHPSFC and APCI parameters) on MS response was studied to understand the behaviour of analytes in UHPSFC-APCI-MS. The tested parameters were: the corona discharge value, the nebulising gas pressure, the drying gas flow rate, MS source temperature and the mobile phase flow rate (at constant modifier percentage). A factorial experimental design was carried out for this study, which displayed the major and negative role of increased nebulising gas pressure. The factorial design was renewed with the four remaining parameters, allowing to enlighten and explain their different effects on MS responses. Finally, some vegetable oils were analysed by UHPSFC-APCI-HRMS with these optimal conditions to determine the chemical structures of unknown compounds from oily samples.



Coinjecting CO2 and light hydrocarbons with steam into oil sand reservoirs can improve the efficiency of the SAGD (steam assisted gravity drainage) process by reducing the steam oil ratio (SOR). The effects of these solvents on bitumen recovery enhancement depend on reservoir

properties and operating conditions. To investigate the effects of solvents on bitumen viscosity in a solvent aided process, phase behaviors and viscosities of CO2–, C3–, and C4–bitumen systems were measured and modeled at high temperatures. Using the calibrated Peng–Robinson equation of state (PR-EOS), the solubilities of solvents in the Clearwater bitumen sample from the Cold Lake region were predicted. High-pressure and high-temperature equipment using an electromagnetic-based viscometer was customized to measure the viscosities of CO2–, C3–, and C4–bitumen mixtures. The measured viscosity data were used to calibrate a nonlinear viscosity model which was used to predict liquid phase viscosity as a function of solvent solubility and temperature. The effects of solvent dissolution on bitumen viscosity were investigated using PR-EOS and the calibrated viscosity model. The results show that dissolving CO2, C3, and C4 in bitumen decreases its viscosity. This viscosity reduction is lowest and highest in the case of CO2 and C4 dissolution, respectively. The effect of solvent dissolution on viscosity reduction is more pronounced at lower temperatures. EOS predictions and viscosity measurements indicate that increasing concentration of CO2, C3, and C4 above a certain threshold has a limited effect on reducing bitumen viscosity. At threshold solvent concentrations, bitumen viscosity can be reduced by 1.7, 5.6, and 15.2 times using CO2, C3, and C4, respectively, at 120 °C. Solubility and viscosity data suggest that C4 has the potential to be used in hot-solvent recovery methods in shallow and deep oil sand reservoirs. C3 may be a more effective solvent in deeper reservoirs which allow higher operating pressures. The modified viscosity model showed better performance than the Lobe and Shu correlations and logarithmic mixing rule. This model improves existing correlations for predicting viscosities of light solvent−bitumen mixtures since it requires less input data and does not require density data.



Benthic macrofauna is an important component linking pelagic and benthic ecosystems, especially in productive coastal areas. Through their metabolism and behaviour, benthic animals affect biogeochemical fluxes between the sediment and water column. Mechanistic models that quantify these benthic-pelagic links are imperative to understand the functioning of coastal ecosystems. In this study, we develop a dynamic model of benthic macrofauna to quantify the relationship between organic matter input and benthic macrofaunal biomass in the coastal zone. The model simulates the carbon dynamics of three functional groups of benthic macrofauna and their sediment food sources and is forced by a hydrodynamic-biogeochemical model simulating pelagic physical and biological dynamics. The model reproduces measured time-series of macrofaunal biomass from two coastal sites with contrasting sedimentation in the Baltic Sea in 1993–2005 with comparatively high accuracy, including a major increase at one of the sites dominated by the bivalve Limecola (Macoma) balthica. This shift in community composition suggests altered pathways of organic matter degradation: 39% of simulated sedimentation was mineralised by macrofauna in 2005 compared to 10% in 1995. From the early 2000s onward macrofaunal biomass seems to be food-limited, as ca 80% of organic carbon sedimentation was processed by the deposit-feeding macrofauna at both sites. This model is a first step to help quantify the role of macrofauna in marine coastal ecosystem functioning and biogeochemical cycles and build predictive capacity of the effects of anthropogenic stressors, such as eutrophication and climate change, on coastal ecosystems.

Elahi, S.M., Scott, C.E., Chen, Z., Pereira-Almao, P., 2019. In-situ upgrading and enhanced recovery of heavy oil from carbonate reservoirs using nano-catalysts: Upgrading reactions analysis. Fuel 252, 262-271.


Exploitation of heavy/extra heavy oil is becoming challenging as it conventionally requires injection of steam in high proportions, making it not environmentally friendly. In-situ upgrading technology (ISUT) is a novel alternative to the current heavy oil and bitumen production methods, which gives the benefits of both oil recovery and upgrading in one single stage. In this method, recovered vacuum residue (VR) from produced oil along with nano-catalyst and hydrogen will be injected in the reservoir, where upgrading reactions take place. For the first time, a comprehensive kinetic analysis of mild hydrocracking reactions inside a carbonate rock is implemented, which considerably enhances predictive simulations of the technology. With the aid of a continuous experimental setup, nano-catalyst deposition into the rock is also assessed in carbonate cores. Furthermore, a five-lumped kinetic model is developed and matched against experimental data with an average error of 6%. Significant viscosity reduction of 99.8% and API gravity increase of 8 °API are observed for the most severe condition with 35% VR conversion, while asphaltene stability criterion is met. It is recurrently omitted in most in-reservoir upgrading reports and the literature the essentially relevant information about oil stability limits. Non-catalytic conversion of heavy oils, disregarding the energy source employed, is most certain to produce unstable asphaltenes and/or coke before reaching surface transportability viscosity requirements, with additional mid-long term reservoir impairment consequences. It is included in this paper the required confirmation that the in-situ upgraded oil is fully stable when transportable viscosity values are reached.

Elhusseiny, S.M., Amin, H.M., Shebl, R.I., 2019. Modulation of laccase transcriptome during biodegradation of naphthalene by white rot fungus Pleurotus ostreatus. International Microbiology 22, 217-225.

https://doi.org/10.1007/s10123-018-00041-5

Biodegradation of polycyclic aromatic hydrocarbons (PAHs) using Pleurotus ostreatus was investigated in the current study along with the expression levels of laccase genes involved in biodegradation under variable conditions. Biodegradation of PAHs (naphthalene, anthracene, and 1,10-phenanthroline) was detected spectrophotometrically. Recorded data revealed that biodegradation of the tested PAHs was time dependent. Elevated level of naphthalene biodegradation (86.47%) was observed compared to anthracene (27.87%) and 1,10-phenanthroline (24.51%) within 3 days post incubation. Naphthalene was completely degraded within 5 days. Further incubation enhanced the biodegradation of both anthracene and 1,10-phenanthroline until reaches 93.69% and 92.00% biodegradation of the initial concentration within an incubation period of 11 and 14 days, respectively. Naphthalene was selected as a PAH model. HPLC and thin layer chromatography of naphthalene biodegradation products at time intervals proposed that naphthalene was first degraded to α- and β-naphthol which was further metabolized to salicylic and benzoic acid. The metabolic pathway of naphthalene degradation by this fungus was elucidated based on the detected metabolites. The expression profile of six laccase isomers was evaluated using real-time PCR. The transcriptome of the fungal laccase isomers recorded higher levels of transcription under optimized fermentation conditions especially in presence of both naphthalene and Tween 80. The accumulation of such useful metabolites from the biodegradation of PAH pollutants recommended white rot fungus as a potential candidate for production of platform chemicals from PAH wastes.



Carbonated water injection (CWI) has been well investigated to improve oil recovery when compared to other enhanced oil recovery (EOR) techniques both in the secondary and tertiary modes. Extra oil recovery and CO2 sequestration associated with CWI have been studied through several experimental works. There are not adequate number of modelling studies about the CWI operation in the open sources because of the complex multi-physics involved with the fluid-fluid and fluid-rock interactions during CWI processes. Hence, further experimental and modelling investigations are needed to be conducted on CWI to systematically capture/comprehend the governing physics and complex displacement mechanisms. This research work will focus on the analysis of vital aspects such as oil recovery amount (and mechanisms), fluids distribution, and effects of operational parameters and well placement on the performance of CWI for both EOR and CO2 sequestration purposes. To achieve these objectives, a 3-D heterogenous reservoir model is developed using the experimental data reported in the recent literature. A new approach of using the grid local pressure to model CWI is adopted where the moles of CO2/water are controlled by their injection rates. The dissolution of CO2 in water is modeled by the Henry’s law for each subsequent grid local pressure. In this research, it is found that through CWI, an additional oil recovery can be achieved when compared to plain (conventional) waterflooding (WF) in the secondary recovery mode. A subsequent increase in the injection pressure leads to more dissolution of CO2 and enhancement of the overall performance of CWI. There is an optimum injector rate, which ensures an effective mass transfer across phases. An optimal well orientation will also give a better recovery performance during CWI. The amount of CO2

stored is also illustrated in this work as an additional benefit achieved in the CWI processes.

Fahandezhsaadi, M., Amooie, M.A., Hemmati-Sarapardeh, A., Ayatollahi, S., Schaffie, M., Ranjbar, M., 2019. Laboratory evaluation of nitrogen injection for enhanced oil recovery: Effects of pressure and induced fractures. Fuel 253, 607-614.


Nitrogen has emerged as a suitable alternative to carbon dioxide for injection into hydrocarbon reservoirs worldwide to enhance the recovery of subsurface energy. Nitrogen typically costs less than CO2 and natural gas, and has the added benefit of being widely available and non-corrosive. However, the underlying mechanisms of recovery following N2 injection into fractured reservoirs that make up a large portion of the world’s oil and gas reserves are not well understood. Here we present the laboratory results of N2 injection into carbonate rocks acquired from a newly developed oil reservoir in Iran with a huge N2-containing natural gas reservoir nearby. We investigate the effectiveness of N2 injection for enhanced oil recovery in immiscible conditions before and after gas breakthrough under a low and high differential pressures across the core. In addition to the effects of pressure, we further illuminate the impacts of fractures—induced on the cores—to assess the displacement behavior and oil recovery factor. Our findings show that an ultimate oil recovery factor of more than 40% can be achieved by N2 injection in non-fractured cores even at immiscible conditions. The ultimate recovery and the onset times for oil production and gas breakthrough are found to be lowered by increasing differential pressures as well as inducing fractures (e.g., 17% reduction in ultimate recovery due to fracturing). However, at a given time when gas-oil interface has not yet reached the production zone (outlet), both increasing differential pressures and fractures transiently enhance the recovery efficiency. As a result, the impact of fractures is more pronounced in lower differential pressures, while the impact of differential pressures is stronger in the absence of fractures. Interestingly, our results attest to the role of molecular diffusion across fracture-matrix interface as the main recovery mechanism in fractured media, which controls the system dynamics before and after breakthroughs. The results not only provide a new perspective into how differential pressures and fractures fundamentally control the effectiveness of N2 flooding but also further show the promising prospects N2 injection for EOR even at immiscible conditions.

Fakhraee, M., Hancisse, O., Canfield, D.E., Crowe, S.A., Katsev, S., 2019. Proterozoic seawater sulfate scarcity and the evolution of ocean–atmosphere chemistry. Nature Geoscience 12, 375-380.

https://doi.org/10.1038/s41561-019-0351-5

Oceanic sulfate concentrations are widely thought to have reached millimolar levels during the Proterozoic Eon, 2.5 to 0.54 billion years ago. Yet the magnitude of the increase in seawater sulfate concentrations over the course of the Eon remains largely unquantified. A rise in seawater sulfate concentrations has been inferred from the increased range of marine sulfide δ34S values following the Great Oxidation Event and was induced by two processes: enhanced oxidative weathering of sulfides on land, and the onset of marine sulfur redox cycling. Here we use mass balance and diagenetic reaction-transport models to reconstruct the sulfate concentrations in Proterozoic seawater. We find that sulfate concentrations remained below 400 µM, and were possibly as low as 100 µM, throughout much of the Proterozoic. At these low sulfate concentrations, relatively large sulfate–pyrite sulfur isotope differences cannot be explained by sulfate reduction alone and are only possible through oxidative sediment sulfur cycling. This requires oxygen concentrations of at least 10 µM in shallow Proterozoic seawater, which translates to 1–10% of present atmospheric oxygen concentrations. At these oxygen and sulfate concentrations, the oceans would have been a substantial source of methane to the atmosphere (60–140 Tmol yr−1). This methane would have accumulated to high concentrations (more than 25 ppmv) and supported greenhouse warming during much of the Proterozoic Eon, with notable exceptions during the Palaeoproterozoic and Neoproterozoic eras.

Fall, T., Kuja-Halkola, R., Dobney, K., Westgarth, C., Magnusson, P.K.E., 2019. Evidence of large genetic influences on dog ownership in the Swedish Twin Registry has implications for understanding domestication and health associations. Scientific Reports 9, Article 7554.

https://doi.org/10.1038/s41598-019-44083-9

Dogs were the first domesticated animal and, according to the archaeological evidence, have had a close relationship with humans for at least 15,000 years. Today, dogs are common pets in our society and have been linked to increased well-being and improved health outcomes in their owners. A dog in the family during childhood is associated with ownership in adult life. The underlying factors behind this association could be related to experiences or to genetic influences. We aimed to investigate the heritability of dog ownership in a large twin sample including all twins in the Swedish Twin Registry born between 1926 and 1996 and alive in 2006. Information about dog ownership was available from 2001 to 2016 from national dog registers. The final data set included 85,542 twins from 50,507 twin pairs with known zygosity, where information on both twins were available in 35,035 pairs. Structural equation modeling was performed to estimate additive genetic effects (the heritability), common/shared environmental, and unique/non-shared environmental effects. We found that additive genetic factors largely contributed to dog ownership, with heritability estimated at 57% for females and 51% for males. An effect of shared environmental factors was only observed in early adulthood. In conclusion, we show a strong genetic contribution to dog ownership in adulthood in a large twin study. We see two main implications of this finding: (1) genetic variation may have contributed to our ability to domesticate dogs and other animals and (2) potential pleiotropic effects of genetic variation affecting dog ownership should be considered in studies examining health impacts of dog ownership.

Fallaise, D., Konzuk, J., Cheyne, C., Mack, E.E., Longstaffe, J.G., 2019. Nontargeted analysis of a non-aqueous-phase liquid from a chemical manufacturing site using nuclear magnetic resonance spectroscopy. Environmental Toxicology and Chemistry 38, 947-955.

https://doi.org/10.1002/etc.4394

Non‐aqueous‐phase liquids (NAPLs), composed primarily of organic solvents and other immiscible liquids, can be found in the subsurface at many industrial sites. The chemical composition of NAPLs is often complex and, in many instances, difficult to fully characterize using conventional analytical techniques based on targeted compound analysis. Incomplete characterization of NAPLs leaves gaps in the understanding of the chemical profile at an impacted site. Previous work has shown that nuclear magnetic resonance (NMR) spectroscopy may be able to assist in the improved characterization of complex NAPL samples. In general, NMR spectroscopy provides an unbiased approach for the analysis of organic compounds because different classes of compounds are all treated and analyzed using the same methods. In addition, NMR spectroscopy provides unique structural information that can be used to elucidate unknowns. The present study describes the use of NMR spectroscopy as a nontargeted tool to characterize the composition of NAPLs collected from an impacted site. It is shown that NMR spectroscopy can be a complementary tool to be used in site assessments to help provide improved understanding of NAPL chemistry, leading to the development of improved conceptual site models and improved strategies for remedial and managerial activities at impacted sites.

Fan, C., Li, S., Luo, M., Zhou, L., Zhang, H., Yang, Z., 2019. Effects of N and S functionalities on binary gas co-adsorption on a coal macromolecule. Energy & Fuels 33, 3934-3946.


Effects of N and S functionalities on co-adsorption of CH4 + N2 and CH4 + CO2 on the coal vitrinite macromolecule model (CVMM) were explored using molecule simulation. Inclusion of the sulfoxide, amine, and sulfide functionalities can enhance SCO2/CH4 (selectivity of CO2 over CH4), while the pyrrole and pyridine functionalities could not. The higher mole fraction of CO2 could reduce the pressure required to reach the stable equilibrium state as well as SCO2/CH4. Microporous calculation results suggest that the microporous size distribution (MSD) of amine–CVMM (median pore size, DM, 8.24 Å; free volume probed by He, VdF, 7105.55 Å3/cell) and sulfoxide–CVMM (DM, 7.92 Å; VdF, 7812.96 Å3/cell) are most suitable for CH4 adsorption, followed by pyrrole–CVMM (DM, 7.18 Å; VdF, 6812.96 Å3/cell). The inclusion of N and S functionalities can distinctly increase the adsorption affinity of the linear molecular configurations of adsorbates by changing the adsorption orientations. The target N and S functionalities in functionalized CVMMs contribute primarily to the adsorption process of these three gaseous adsorbates. The adjacent functionalities have critical influences on adsorption affinity for these three adsorbate species depending upon the relative adsorption affinity strength of the adjacent functionalities and the target functionalities.

Fang, X., Wu, L., Geng, A., Deng, Q., 2019. Formation and evolution of the Ediacaran to Lower Cambrian black shales in the Yangtze Platform, South China. Palaeogeography, Palaeoclimatology, Palaeoecology 527, 87-102.


Black shales in the Ediacaran Doushantuo Formation (predominantly from Member II, IV and equivalent strata) and the Lower Cambrian Niutitang Formation (or equivalents) occur widely in the

Yangtze Platform, South China. These black shales could provide sufficient hydrocarbons for the petroleum system in this region. However, biomarker parameters have proven invalid in the assessment of petroleum resources because of the high thermal maturity. Therefore, it is necessary to study the characteristics and formation mechanisms of these two black shales. This study analyzed redox-sensitive elements, total organic carbon (TOC) contents, and carbon isotopic compositions of organic matter in four continuous sedimentary successions including the two investigated shales in the Yangtze Platform (namely Jiulongwan on the inner shelf, Songlin in an intra-shelf lagoon, Dongkanshang on the upper slope, and Fengtan in the basin). Combined with other previously reported five sections, the redox conditions of sedimentary waters and marine paleoproductivity of the Ediacaran to Lower Cambrian black shales in the Yangtze Platform were discussed and compared. The results showed that the redox conditions of the Early Cambrian in the study area were similar to those of the Ediacaran Doushantuo period, which were oxic-suboxic at surface water, and anoxic in the deep with the occurrence of euxinic conditions. However, the euxinic conditions in the deep waters were distributed more widely in the Early Cambrian than in the Ediacaran period. The source of organic matter in the Doushantuo Formation was dominated by algae in the shallow-water platform and the shelf-margin areas, while chemoautotrophic/methanotrophic biomass may also have contributed in the intra-shelf lagoon and deep-water basin areas. In contrast, the organic matter of the Niutitang Formation was mainly contributed by the chemoautotrophic/methanotrophic biomass, with a minor contribution by photosynthetic algae and cyanobacteria. During the Doushantuo period, the input of terrigenous clastic materials was low, resulting in the enrichment of organic matter and formation of organic-rich black shale in the Yangtze Platform over a long geological time period. Compared to the Doushantuo period, the shorter sedimentation time and the higher deposition rate during the Early Cambrian produced a thicker and higher-quality Niutitang Formation source rock widely distributed in the Yangtze Platform.

Farhadian Babadi, M., Mehrabi, B., Tassi, F., Cabassi, J., Vaselli, O., Shakeri, A., Pecchioni, E., Venturi, S., Zelenski, M., Chaplygin, I., 2019. Origin of fluids discharged from mud volcanoes in SE Iran. Marine and Petroleum Geology 106, 190-205.


Onshore and offshore mud volcanism in the Makran accretionary prism is related to convergence of the Arabian and Eurasian plates. This study describes the chemical and isotopic composition of hydrocarbon-rich fluids from four active on-shore mud volcanoes located along the Makran coast (southern Iran), namely Borborok, Ain, Napag and Sand Mirsuban (Makran coast, southern Iran), as well as Pirgel mud volcano (SE Iran) that is located between the Taftan and Bazman igneous volcanoes. The main aim was to provide insights into the source region(s) of gases and waters discharged from these systems and the secondary processes controlling their chemical features. The four on-shore mud volcanoes emitted CH4-dominated gases, with significant concentrations of C2+ alkanes suggesting a dominant thermogenic origin, as confirmed by their δ13C–CH4 values. Carbon dioxide was present at relatively low concentrations (0.78–2.33%) with an isotopic signature (δ13C-CO2 from −34.2 to −11.1‰ vs. V-PDB) in the range of that typical of thermogenic gases. Hence, the geochemical features of these mud volcanoes point to the occurrence of a deep gas source rich in hydrocarbons, although the occurrence of an exploitable gas reservoir has to be confirmed by geophysical measurements and detailed geostructural surveys. Gas chemistry from Pirgel mud volcano completely differs with respect to that of the previous ones, since the former emits gases dominated by CO2 and showing relatively high R/Ra values (≈1.6), suggesting a significant fluid contribution from the nearby volcanic systems. Moreover, waters from the on-shore mud volcanoes showed a Na-Cl composition, typically associated with mud volcanism, whereas those discharged from Pirgel were Na-HCO3-type and rich in chemical species typical of hydrothermal fluids such as

As. Waters from the on-shore volcanoes were characterized by a strong δ18O-positive shift and high B and Li concentrations, likely indicating clay mineral dehydration and long-term water-rock interaction. Such geochemical features were also shown by the waters from Pirgel, where the high concentrations of B and Li were possibly related to volcanic source. Estimated temperatures for the on-shore mud volcanoes estimated using the Mg–Li and Mg-K geothermometers range from 84 to 165 °C, corresponding to 3–7 km depth.

Farmer, J.R., Hönisch, B., Haynes, L.L., Kroon, D., Jung, S., Ford, H.L., Raymo, M.E., Jaume-Seguí, M., Bell, D.B., Goldstein, S.L., Pena, L.D., Yehudai, M., Kim, J., 2019. Deep Atlantic Ocean carbon storage and the rise of 100,000-year glacial cycles. Nature Geoscience 12, 355-360.

https://doi.org/10.1038/s41561-019-0334-6

Over the past three million years, Earth’s climate oscillated between warmer interglacials with reduced terrestrial ice volume and cooler glacials with expanded polar ice sheets. These climate cycles, as reflected in benthic foraminiferal oxygen isotopes, transitioned from dominantly 41-kyr to 100-kyr periodicities during the mid-Pleistocene 1,250 to 700 kyr ago (ka). Because orbital forcing did not shift at this time, the ultimate cause of this mid-Pleistocene transition remains enigmatic. Here we present foraminiferal trace element (B/Ca, Cd/Ca) and Nd isotope data that demonstrate a close linkage between Atlantic Ocean meridional overturning circulation and deep ocean carbon storage across the mid-Pleistocene transition. Specifically, between 950 and 900 ka, carbonate ion saturation decreased by 30 µmol kg−1 and phosphate concentration increased by 0.5 µmol kg−1 coincident with a 20% reduction of North Atlantic Deep Water contribution to the abyssal South Atlantic. These results demonstrate that the glacial deep Atlantic carbon inventory increased by approximately 50 Gt during the transition to 100-kyr glacial cycles. We suggest that the coincidence of our observations with evidence for increased terrestrial ice volume reflects how weaker overturning circulation and Southern Ocean biogeochemical feedbacks facilitated deep ocean carbon storage, which lowered the atmospheric partial pressure of CO2 and thereby enabled expanded terrestrial ice volume at the mid-Pleistocene transition.

Fein, J.B., Yu, Q., Nam, J., Yee, N., 2019. Bacterial cell envelope and extracellular sulfhydryl binding sites: Their roles in metal binding and bioavailability. Chemical Geology 521, 28-38.


Although carboxyl and phosphoryl functional groups within the bacterial cell envelope and on bacterial extracellular polymeric substance (EPS) molecules are the most abundant metal binding sites, recent studies suggest that sulfhydryl sites control the binding of chalcophile and similar elements under environmentally-relevant metal loading conditions. The role of cell surface sulfhydryl sites in metal binding has been demonstrated unambiguously for Zn, Cd, Hg, Cu, Au, and Se. This review article summarizes our current understanding of the nature, concentration, and reactivity of these important metal binding sites, their distribution between the cell envelope and extractable EPS molecules, and their possible role in controlling bacterial bioavailability of some elements. The objective of the review is to summarize the relatively few studies that have focussed on bacterial sulfhydryl sites, and to identify areas in which future research may be most productive.

Sulfhydryl sites comprise only approximately 5–10% of the total binding site concentration of bacterial cell envelopes, but exhibit such a high affinity for some metals that under low metal loading conditions, sulfhydryl binding of metals is responsible for nearly 100% of the adsorbed metal budget. Recent experimental results have revealed that the concentration and distribution of sulfhydryl sites

between cell envelope macromolecules and cell-produced EPS are dependent on the bacterial species, growth phase, and growth conditions. For example, the cell envelope sulfhydryl site concentrations of Bacillus subtilis increase with increasing glucose concentration in the growth medium. Shewanella oneidensis cells contain high concentrations of sulfhydryl sites within their cell envelopes with much lower concentrations present on EPS molecules, while Pseudomonas putida cells exhibit the opposite. We apply a proteomics approach to explain the observed differences in sulfhydryl distributions for S. oneidensis and P. putida. The proteomics analysis indicates that the outer membrane proteins of S. oneidensis contains a high concentration of cysteine residues, while the cell surface proteins of P. putida are relatively cysteine-poor, with cysteine-rich proteins of P. putida associated predominately with EPS materials. The results of this proteomics analysis demonstrate the potential to identify the range of possible protein hosts for metal binding sulfhydryl sites, and the approach represents a means for predicting the concentration and distribution of sulfhydryl metal binding sites on bacterial cells and EPS molecules.

Fernandes, V.A., Hopp, J., Schwarz, W.H., Fritz, J.P., Trieloff, M., Povenmire, H., 2019. 40Ar-39Ar step heating ages of North American tektites and of impact melt rock samples from the Chesapeake Bay impact structure. Geochimica et Cosmochimica Acta 255, 289-308.


This study presents 40Ar-39Ar step heating ages of four North American tektites (three bediasites and one georgiaite) and of two groundmass samples extracted at different depths from clast-rich impact melt rocks (CB-W61 and CB-W84) recovered by the USGS-ICDP Eyreville B drill-core about 9 km from the centre of the Chesapeake Bay impact structure. Radiometric age determination on both North American tektites and impact melt rocks from within Chesapeake Bay crater offers the first possibility to confirm the origin of these tektites. For this aim, argon isotopic data from 13 samples/aliquots of tektite rims, cores and bulk, and 4 samples/aliquots from two impact melt rocks were obtained over 15 to 26 step heating extractions. Age spectra of all tektite samples show plateaux comprising 62–98% of the 39Ar release over consecutive intermediate and high temperature heating steps. Few low temperature extractions indicate excess 40Ar. Inverse isochron 40Ar/36Ar intercepts of tektite samples are indistinguishable from air (295.5). However, impact melt rock spectra presented complex Ar-release affecting primarily the low temperature heating-steps. Inverse isochrones indicate excess argon from which the 40Ar/36Ar intercept was used to correct the age calculation. CB-W61 and CB-W61-2 40Ar/36Ar intercepts are 354.5 ± 2.5 and 327.2 ± 6.3, respectively, and those for CB-W84 and CB-W84-2 are 332.0 ± 7.3 and 329.6 ± 5.6, respectively. The inverse isochron weighted mean age (according to currently suggested K-decay constants revisions by Schwarz et al. (2011) and Renne et al. (2011)) for all four tektites is 34.86 ± 0.25 Ma (MSWD = 0.96, P = 0.41; n = 4) and for the two impact melt rocks is 37.16 ± 3.65 Ma (MSWD = 0.83, P = 0.36). The combined tektite and impact melt rocks isochron mean age of 34.86 ± 0.23 (0.32) Ma (MSWD = 0.87, P = 0.43) is slightly – though not significantly – higher than the plateau mean age of 34.55 ± 0.27 (0.36) Ma (MSWD = 0.66, P = 0.62). Placing this age in the Global Stratotype Section and Point (GSSP) marine section exposed at Massignano, Italy, it falls below the Eocene/Oligocene (E/O) boundary overlapping with the 10.28 m Ir-anomaly. These results agree within errors with previously reported ages of 35.20 ± 0.54 Ma, especially those derived from K-Ar and Ar-Ar total fusion analysis. An age of 34.86 ± 0.32 Ma sets the Chesapeake Bay impact event close to the youngest of the three Ir anomalies at ∼35.0 Ma in the case the impactor was Ir-rich (e.g, a chondrite, primitive achondrite, stony-iron or iron meteorite). The concordance with the E/O boundary at ∼33.9 Ma seems only marginally possible, and only if the Ir contribution from the ejecta were, potentially, due either to its small amount becoming diluted in the geologic record or the impactor being Ir poor, e.g., of differentiated achondritic composition. This study also brings to front the need to re-establish the

stratigraphic and palaeo-magnetic correlations across the globe for the Ir-anomalies and the magneto-stratigraphy during the mid- to late-Eocene and early-Oligocene, and the need to re-evaluate the markers for the Eocene-Oligocene boundary.

Fernando, H., Ju, H., Kakumanu, R., Bhopale, K.K., Croisant, S., Elferink, C., Kaphalia, B.S., Ansari, G.A.S., 2019. Distribution of petrogenic polycyclic aromatic hydrocarbons (PAHs) in seafood following Deepwater Horizon oil spill. Marine Pollution Bulletin 145, 200-207.


A community-based participatory research was utilized to address the coastal community's concern regarding Deepwater Horizon oil contamination of seafood. Therefore, we analyzed polycyclic aromatic hydrocarbons (PAHs), major toxic constituents of crude oil, in the seafood collected from gulf coast (Louisiana, Alabama and Mississippi) during December 2011–February 2014. PAHs were extracted from edible part of shrimp, oysters, and crabs by the QuEChERS/dsPE procedure and analyzed by gas chromatography–mass spectrometry. The total PAHs data were further analyzed using the General Linear Mixed Model procedure of the SAS (Version 9.3, SAS Institute, Inc., Cary, NC) statistical software. Brown shrimp showed statistically significant differences in PAHs levels with respect to time and locations while white shrimp showed differences at various time points. PAHs levels in oyster and crab samples were not statistically different at the Type I error of 0.05. Overall, the PAHs levels are far below FDA levels of concern for human consumption.

Finnegan, S., Gehling, J.G., Droser, M.L., 2019. Unusually variable paleocommunity composition in the oldest metazoan fossil assemblages. Paleobiology 45, 235-245.

https://doi.org/10.1017/pab.2019.1

Recent excavations of Ediacaran assemblages have revealed striking bed-to-bed variation in diversity–abundance structure, offering potential insight into the ecology and taphonomy of these poorly understood early Metazoan ecosystems. Here we compare faunal variability in Ediacaran assemblages to that of younger benthic assemblages, both fossil and modern. We decompose the diversity of local assemblages into within-collection (α) and among-collection (β) components and show that β diversity in Ediacaran assemblages is unusually high relative to younger assemblages. Average between-bed ecological dissimilarities in the Phanerozoic fossil record are comparable to within-habitat dissimilarities typically observed over meter to kilometer scales in modern benthic marine habitats, but dissimilarities in Ediacaran assemblages are comparable to those typically observed over 10–100 km scales in modern habitats. We suggest that the unusually variable diversity–abundance structure of Ediacaran assemblages is due both to their preservation as near snapshots of benthic communities and to original ecological differences, in particular the paucity of motile taxa and the near lack of predation and infaunalization.

Fomitšov, M., 2019. Low-temperature supercritical conversion of kukersite oil shale. Oil Shale 3, 171-178.


The thermal decomposition of Estonian Kukersite oil shale under supercritical conditions was carried out using a continuous flow tubular reactor. The effects of the retorting times of 0, 30, 60 and 120 minutes on the yield of thermobitumen (TB), solid residue, oil, gas, coke and undecomposed kerogen at temperatures of 390 °C and 420 °C were investigated. The maximum yield of organics was 93.8%

by using the benzene solvent at 420 °C. The influence of physicochemical factors on the efficiency of liquefaction under supercritical conditions was studied. The reaction conditions and solvent for maximum extraction were established.

Forgan, D.H., 2019. Exoplanet transits as the foundation of an interstellar communications network. International Journal of Astrobiology 18, 189-198.

https://doi.org/10.1017/S1473550417000283

Two fundamental problems for extraterrestrial intelligences (ETIs) attempting to establish interstellar communication are timing and energy consumption. Humanity's study of exoplanets via their transit across the host star highlights a means of solving both problems. An ETI ‘A’ can communicate with ETI ‘B’ if B is observing transiting planets in A's star system, either by building structures to produce artificial transits observable by B, or by emitting signals at B during transit, at significantly lower energy consumption than typical electromagnetic transmission schemes. This can produce a network of interconnected civilizations, establishing contact via observing each other's transits. Assuming that civilizations reside in a Galactic Habitable Zone (GHZ), I conduct Monte Carlo Realization simulations of the establishment and growth of this network, and analyse its properties in the context of graph theory. I find that at any instant, only a few civilizations are correctly aligned to communicate via transits. However, we should expect the true network to be cumulative, where a ‘handshake’ connection at any time guarantees connection in the future via e.g. electromagnetic signals. In all our simulations, the cumulative network connects all civilizations together in a complete network. If civilizations share knowledge of their network connections, the network can be fully complete on timescales of order a hundred thousand years. Once established, this network can connect any two civilizations either directly, or via intermediate civilizations, with a path much less than the dimensions of the GHZ.


https://doi.org/10.1017/pab.2019.4

The Ordovician was a time of drastic biological and geological change. Previous work has suggested that there was a dramatic increase in global diversity during this time, but also has indicated that regional dynamics and dynamics in specific environments might have been different. Here, we contrast two paleocontinents that have different geological histories through the Ordovician, namely Laurentia and Baltica. The first was situated close to the equator throughout the whole Ordovician, while the latter has traversed tens of latitudes during the same time. We predict that Baltica, which was under long-term environmental change, would show greater average and interval-to-interval origination and extinction rates than Laurentia. In addition, we are interested in the role of the environment in which taxa originated, specifically, the patterns of onshore–offshore dynamics of diversification, where onshore and offshore areas represent high-energy and low-energy environments, respectively. Here, we predict that high-energy environments might be more conducive for originations.

Our new analyses show that the global Ordovician spike in genus richness from the Dapingian to the Darriwilian Stage resulted from a very high origination rate at the Dapingian/Darriwilian boundary, while the extinction rate remained low. We found substantial interval-to-interval variation in the origination and extinction rates in Baltica and Laurentia, but the probabilities of origination and extinction are somewhat higher in Baltica than Laurentia. Onshore and offshore areas have largely

indistinguishable origination and extinction rates, in contradiction to our predictions. The global spike in origination rates at the Dapingian/Darriwilian boundary is apparent in Baltica, Laurentia, and onshore and offshore areas, and abundant variability in diversification rates is apparent over other time intervals for these paleocontinents and paleoenvironments. This observation hints at global mechanisms for the spike in origination rates at the Dapingian/Darriwilian boundary but a domination of more regional and local mechanisms over other time intervals in the Ordovician.

Fredens, J., Wang, K., de la Torre, D., Funke, L.F.H., Robertson, W.E., Christova, Y., Chia, T., Schmied, W.H., Dunkelmann, D.L., Beránek, V., Uttamapinant, C., Llamazares, A.G., Elliott, T.S., Chin, J.W., 2019. Total synthesis of Escherichia coli with a recoded genome. Nature 569, 514-518.

https://doi.org/10.1038/s41586-019-1192-5

Nature uses 64 codons to encode the synthesis of proteins from the genome, and chooses 1 sense codon—out of up to 6 synonyms—to encode each amino acid. Synonymous codon choice has diverse and important roles, and many synonymous substitutions are detrimental. Here we demonstrate that the number of codons used to encode the canonical amino acids can be reduced, through the genome-wide substitution of target codons by defined synonyms. We create a variant of Escherichia coli with a four-megabase synthetic genome through a high-fidelity convergent total synthesis. Our synthetic genome implements a defined recoding and refactoring scheme—with simple corrections at just seven positions—to replace every known occurrence of two sense codons and a stop codon in the genome. Thus, we recode 18,214 codons to create an organism with a 61-codon genome; this organism uses 59 codons to encode the 20 amino acids, and enables the deletion of a previously essential transfer RNA.

Frick, A.A., Weyermann, C., 2019. An untargeted lipidomic approach for qualitative determination of latent fingermark glycerides using UPLC-IMS-QToF-MSE. Analyst 144, 3590-3600.

http://dx.doi.org/10.1039/C9AN00521H

More detailed fundamental information is required about latent fingermark composition in order to better understand fingermark properties and their impact on detection efficiency, and the physical and chemical changes that occur with time following deposition. The composition of the glyceride fraction of latent fingermark lipids in particular is relatively under-investigated due in part to their high structural variability and the limitations of the analytical methods most frequently utilised to investigate fingermark composition. Here, we present an ultra performance liquid chromatography-ion mobility spectroscopy-quadrupole time-of-flight mass spectrometry (UPLC-IMS-QToF-MSE) method to characterise glycerides in charged latent fingermarks using data-independent acquisition. Di- and triglycerides were identified in fingermark samples from a population of 10 donors, through a combination of in silico fragmentation and monitoring for fatty acid neutral losses. 23 diglycerides and 85 families of triglycerides were identified, with significant diversity in chain length and unsaturation. 21 of the most abundant triglyceride families were found to be common to most or all donors, presenting potential targets for further studies to monitor chemical and physical changes in latent fingermarks over time. Differences in relative peak intensities may be indicative of inter- and intra-donor variability. While this study represents a promising step to obtaining more in-depth information about fingermark composition, it also highlights the complex nature of these traces.

Frieling, J., Peterse, F., Lunt, D.J., Bohaty, S.M., Sinninghe Damsté, J.S., Reichart, G.J., Sluijs, A., 2019. Widespread warming before and elevated barium burial during the Paleocene-Eocene Thermal

Maximum: Evidence for methane hydrate release? Paleoceanography and Paleoclimatology 34, 546-566.

https://doi.org/10.1029/2018PA003425

Abstract Current climate change may induce positive carbon cycle feedbacks that amplify anthropogenic warming on time scales of centuries to millennia. Similar feedbacks might have been active during a phase of carbon cycle perturbation and global warming, termed the Paleocene-Eocene Thermal Maximum (PETM, 56 million years ago). The PETM may help constrain these feedbacks and their sensitivity to warming. We present new high-resolution carbon isotope and sea surface temperature data from Ocean Drilling Program Site 959 in the Equatorial Atlantic. With these and existing data from the New Jersey Shelf and Maud Rise, Southern Ocean, we quantify the lead-lag relation between PETM warming and the carbon input that caused the carbon isotope excursion (CIE). We show ~2 °C of global warming preceded the CIE by millennia, strongly implicating CO2-driven warming triggered a positive carbon cycle feedback. We further compile new and published barium (Ba) records encompassing continental shelf, slope, and deep ocean settings. Based on this compilation, we calculate that average Ba burial rates approximately tripled during the PETM, which may require an additional source of Ba to the ocean. Although the precipitation pathway is not well constrained, dissolved Ba stored in sulfate-depleted pore waters below methane hydrates could represent an additional source. We speculate the most complete explanation for early warming and rise in Ba supply is that hydrate dissociation acted as a positive feedback and caused the CIE. These results imply hydrates are more temperature sensitive than previously considered, and may warrant reconsideration of the political assignment of 2 °C warming as a safe future scenario.

Fu, C., Liu, N., 2019. Waterless fluids in hydraulic fracturing – A review. Journal of Natural Gas Science and Engineering 67, 214-224.


Unconventional resources such as shale gas have attracted increasing global attention with great potential to bridge the energy supply chain. Yet the technical challenges and ecological concerns arise in the attempts to increase resource recovery. Shale reservoirs feature a low permeability water-sensitivity, and geological complexity, which call for more effective stimulation techniques to both reduce water use and boost production. It is believed that technology innovation such as waterless fracturing is the key to effectively improving unconventional resources recovery, while addressing the issue in reducing water consumption and environmental footprints. This paper investigates the development of two major waterless fracturing fluids, foams and liquid N2/CO2, including the advantages and challenges faced with waterless fracturing, fracturing mechanisms, and fluid properties such as stability and rheology. Based on literature review, it is believed that foam has a great potential to be a promising fracturing fluid in improving productivity and long-term production with benefits such as fast cleanup, improved proppant transport, and minimal environmental footprint. Foam properties such as stability and rheology have been continuously improved with technological advances in the stabilizing agents. Foams stabilized by nanoparticles are reported to significantly improved foam stability and rheology under reservoir conditions over conventional surfactants. Other fracturing fluids such as liquid CO2/N2 and gas fracturing fluids are designed to clear formation damage near the wellbore or for scenarios where long fractures are not desired, and both are faced with various technical challenges. This review provides readers with the state-of-the-art research progress regarding the technological advances of waterless fracturing fluids and sheds light on future research areas that can benefit a greener and more effective shale gas development.

Fu, J., Zhang, Z., Chen, C., Wang, T.G., Li, M., Ali, S., Lu, X., Dai, J., 2019. Geochemistry and origins of petroleum in the Neogene reservoirs of the Baiyun Sag, Pearl River Mouth Basin. Marine and Petroleum Geology 107, 127-141.


A total of 25 light oils/condensates (5 condensates from 2 new exploratory wells) were collected from the Baiyun Sag in the Pearl River Mouth Basin (PRMB) in the South China Sea and investigated to establish their origins and sources. Three oil families were identified among samples following analysis of various geochemical parameters using biomarkers, stable carbon isotope compositions, and Hierarchical Cluster Analysis (HCA). Family-I oils, distributed in the northern structural belts, are characterized by significantly high pristane to phytane (Pr/Ph) ratios (4.77–7.93), moderate oleanane to C30 hopane (OL/C30H) ratios (0.18–0.97) and raised bicadinane-T/C30H (T/C30H) ratios (1.67–7.67). Family-II oils are distributed along the eastern flank of the Main Sub Sag towards the northeastern tectonic zones, and, have relatively high Pr/Ph ratios (3.14–4.68), elevated OL/C30H values (0.73–2.29) and moderate T/C30H values (1.64–4.52). The geochemical characteristics of the oils suggest that oils of both Family-I and Family-II are of terrestrial origin, but from two entirely independent sources. Oils of Family-III (a newly discovered oil group) have relatively lower Pr/Ph ratios (0.89–1.99), moderate OL/C30H values (0.13–0.82) and lower T/C30H values (0.34–1.61), indicating a reduced contribution of higher plant organic matter in related source rocks. Family-III oils are consistent in geochemical characteristics with shallow lacustrine source rocks and their related oils discovered in the Zhu I and III depressions of the PRMB, suggesting that they are likely to be derived from source rocks deposited in a shallow lacustrine environment during the Eocene Wenchang-Enping period. The oils of Family-III mainly occur in the southwest flank of the Baiyun Sag, which implies that this is the preferred direction for migration of lacustrine oils. The discovery of lacustrine oil demonstrates that the Baiyun Sag possesses enormous exploration potential in lacustrine oils and that this may become the next favored petroleum exploration target.

Funkey, C.P., Conley, D.J., Stedmon, C.A., 2019. Sediment alkaline-extracted organic matter (AEOM) fluorescence: An archive of Holocene marine organic matter origins. Science of The Total Environment 676, 298-304.


Organic matter (OM) is comprised of a complex mixture of substrates, which are difficult to fully characterize. Therefore a range of analytical approaches is applied to provide a better understanding of the dynamics and biogeochemical cycling of aquatic system. One approach is UV–Visible spectroscopy, which includes measurements of spectral absorption and fluorescence of colored and fluorescent fractions of dissolved OM (DOM, CDOM and FDOM). In this study OM fluorescence is characterized by excitation-emission matrix spectroscopy on alkaline extracted DOM from a Baltic Sea sediment core that spanned 8500 years and fluctuating levels of hypoxia. Our results showed that three underlying fluorescence components had strong correlations with carbon, nitrogen content and δ15N. Our results demonstrate that optical properties of extracted OM from sediments reveal information about OM quality and quantity similar to those of biomarkers, which can be a useful additional tool for investigating OM deposition.

Gafurov, M., Mamin, G., Gracheva, I., Murzakhanov, F., Ganeeva, Y., Yusupova, T., Orlinskii, S., 2019. High-Field (3.4 T) ENDOR investigation of asphaltenes in native oil and vanadyl complexes by asphaltene adsorption on alumina surface. Geofluids 2019, Article 381287.

https://doi.org/10.1155/2019/3812875

Vanadyl porphyrin complexes in asphaltenes from heavy (Karmalinskoye) oil and in asphaltene films obtained as a result of adsorption on the surface of aluminum oxide were studied by electron paramagnetic resonance (EPR) and double electron-nuclear resonance (ENDOR) in the W-band frequency range (microwave frequency of 95 GHz, magnetic field of 3.4 T). Mims ENDOR spectra from 1H and 27Al nuclei are observed. ENDOR spectra are different for native oil and asphaltenes from one side and the adsorbed samples from the other side while no significant changes in X- (microwave frequency of 9 GHz) or W-band EPR spectra are found. The results allow supposing that vanadyl porphyrin complexes (at least in the studied asphaltene films) participate in the formation of asphaltene aggregates through the functional groups rather than π-π interactions. The data show the feasibility of the commercial pulsed ENDOR approaches for the investigation of crude oils and their constituents under external influence.

Galeotti, S., Sprovieri, M., Rio, D., Moretti, M., Francescone, F., Sabatino, N., Fornaciari, E., Giusberti, L., Lanci, L., 2019. Stratigraphy of early to middle Eocene hyperthermals from Possagno (Southern Alps, Italy) and comparison with global carbon isotope records. Palaeogeography, Palaeoclimatology, Palaeoecology 527, 39-52.


The late early Eocene to middle Eocene ~51–45 Million years ago (Ma) time interval in the middle bathyal, pelagic/hemipelagic succession of the western Tethys Possagno section in the Carcoselle quarry (Southern Alps, northeastern Italy), contains several episodes of negative carbon isotope excursions (CIEs) and concomitant dissolution of carbonates. Comparison with previously published carbon isotope records from deep-sea successions allows the identification of long-term trends and short-term events in our record, which provides a sound chemostratigraphic basis for correlation against the robust bio- and magnetostratigraphic scheme available for the studied succession and additional evidence of the global significance of the long-term trend and superposed perturbations tracked changes in δ13C values.

Spectral analysis indicates that CIEs and associated lithological cycles are paced by orbital forcing, similar to what previously observed on the same interval in other deep-sea successions. The identification of astronomically forced geochemical cycles allows us to develop an orbitally tuned age model allowing to test the astrochronology of the ~56.0 Ma to ~47.5 Ma time interval.

Galoski, C.E., Jiménez Martínez, A.E., Schultz, G.B., dos Santos, I., Froehner, S., 2019. Use of n-alkanes to trace erosion and main sources of sediments in a watershed in southern Brazil. Science of The Total Environment 682, 447-456.


Erosive processes can transport sediments containing nutrients, heavy metals and contaminants of organic and inorganic origin into bodies of water, therefore affecting the local ecosystem and the population that benefits from the water sources. In order to better understand the origin of sediment sources and establish mitigation measures, the use of the sediment fingerprinting technique has been highlighted. Thus, the present work had as objective to apply n-alkanes in order to trace and understand the main sources of organic matter in sediments and associate the results with land and soil occupation. The study area is located in the municipality of Rio Negrinho - Brazil, in the Saci river basin. Soil samples were collected and classified according to their use and occupation, as well

as and samples of local vegetation to be used as reference. The distribution of n-alkanes in the sediments was compared with the distribution found in the vegetation and soil. Previously, a distribution pattern of n-alkanes had been identified in all major vegetation used to trace the source of organic matter and hence the soil. The concentrations of total organic carbon (TOC), total nitrogen (TN), total phosphorus (TP) and granulometry were also analyzed in the soil and sediment samples. Indexes between n-alkanes were used and applied to assess the source together with statistical analysis (PCA). In sum, the results showed that the sediments are mainly composed of Pinus taeda reforestation soils, as well as soil from the abandoned roads used to transport the cut trees, while the contribution of autochthonous sediments was found to be minimal. In this way, the fingerprint technique served as an auxiliary tool in order to establish measures for the good management of a river basin, bringing important information about the contributing sources of sediment to water bodies.

Gangl, S.K., Moy, C.M., Stirling, C.H., Jenkyns, H.C., Crampton, J.S., Clarkson, M.O., Ohneiser, C., Porcelli, D., 2019. High-resolution records of Oceanic Anoxic Event 2: Insights into the timing, duration and extent of environmental perturbations from the palaeo-South Pacific Ocean. Earth and Planetary Science Letters 518, 172-182.


Oceanic Anoxic Event 2 (OAE 2), which took place around the Cenomanian–Turonian boundary (∼94 Ma), is associated with extreme perturbations to the global carbon cycle, affected ocean basins worldwide and was associated with significant biological turnover. Although this event has been well studied in the northern hemisphere, the evolution and character of OAE 2, particularly in terms of the vertical and lateral extent of anoxia, is poorly constrained in the palaeo-Pacific Ocean. Furthermore, the precise timing, duration and character of this event, and the exact mechanisms driving OAE 2 environmental changes, are still being debated. Here, we present the first high-resolution records of carbon isotopes, total organic carbon and magnetic susceptibility from the southern palaeo-Pacific Ocean during OAE 2, sampled at two sections in New Zealand. The carbon isotope records from both localities reveal a ∼2‰ positive excursion that represents the global change in the carbon cycle associated with OAE 2. When combined with a cyclostratigraphic age model, these new records constrain the duration of the OAE 2 carbon isotope excursion to at least 930 ± 25 ky and indicate a minimum duration of 200 ± 25 ky for the ‘Plenus Cold Event’ that took place during OAE 2. The lithologies and low organic-carbon contents of the New Zealand sections imply that oxic conditions prevailed along, at least parts of, the margins of the palaeo-Pacific Ocean at mid- to high southern latitudes during OAE 2 while, contemporaneously, conditions were locally anoxic in the mid-water column of the equatorial Pacific Ocean. Despite these apparently oxic conditions in the New Zealand region, there was a partial collapse of benthic ecosystems leading up to, and during, OAE 2, suggesting environmental deterioration caused by intermittent oxygen deprivation, or other chemical or biological disturbances in the South Pacific region that remain to be elucidated.

Gar’kusha, D.N., Fedorov, Y.A., Andreev, Y.A., Tambieva, N.S., Mikhailenko, O.A., 2019. Methane and sulfide sulfur in the bottom sediments of Lake Baikal. Geochemistry International 57, 466-479.

https://doi.org/10.1134/S0016702919040050

The paper analyzes data on the distribution of methane and sulfide sulfur concentrations in the upper layer of the bottom sediments in different areas of Lake Baikal obtained during expeditions in 2014 and 2015. During the study, concentrations of methane and sulfide sulfur in lake sediments varied from <0.01 to 3.69 µg/g dry sediment (mean 0.34 µg/g) and from 0.002 to 0.830 mg/g dry sediment

(mean 0.042 mg/g), respectively. The maximum concentrations of methane were typical of the Northern region, where the waters of the Upper Angara, Kichera rivers flow, and separate stations of profile along the estuary zone of the Selenga River, as well as stations located in the zone of underwater wastewater discharge of Baikalsk and the Baikal pulp and paper mill closed in 2013. A comparison of the distribution of methane and sulfide sulfur concentrations indicates an intense sulfate reduction at the stations with the highest methane concentrations, which suggests the conjugate processes of their generation. Variations of methane and sulfide sulfur concentrations in the studied upper layers of Lake Baikal sediments are caused by the differences in the anthropogenic impact and also by the variability of sedimentation conditions that determine the grain size composition and the content of organic matter, and, as a consequence, the intensity of methanogenesis and sulfate reduction.

Geiger, O., 2019. Biogenesis of Fatty Acids, Lipids and Membranes, Handbook of Hydrocarbon and Lipid Microbiology. Springer, Cham, p. 886.

https://doi.org/10.1007/978-3-319-50430-8

Concise chapters, written by experts in the field, cover a wide spectrum of topics on lipid and membrane formation in microbes (Archaea, Bacteria, eukaryotic microbes).

All cells are delimited by a lipid membrane, which provides a crucial boundary in any known form of life. Readers will discover significant chapters on microbial lipid-carrying biomolecules and lipid/membrane-associated structures and processes.

Biochemistry of Biogenesis of Fatty Acids and LipidsFatty Acids: Introduction. Eric R. Moellering, Victoria L. Prince, Roger C. Prince, Pages 3-23 Synthesis of Acetyl-CoA from Carbon Dioxide in Acetogenic Bacteria, A. Wiechmann, V. Müller,

Pages 25-42 Formation of Fatty Acids, Isabel M. López-Lara, Otto Geiger, Pages 43-55 Formation of Isoprenoids, Jordi Pérez-Gil, Manuel Rodríguez-Concepción, Claudia E. Vickers, Pages

57-85 Formation of Bacterial Glycerol-Based Membrane Lipids: Pathways, Enzymes, and Reactions, Otto

Geiger, Christian Sohlenkamp, Isabel M. López-Lara, Pages 87-107 Ornithine Lipids and Other Amino Acid-Containing Acyloxyacyl Lipids; Christian Sohlenkamp,

Pages 109-122 Bacterial Sphingolipids and Sulfonolipids, Otto Geiger, Jonathan Padilla-Gómez, Isabel M. López-

Lara, Pages 123-137 Phenolic Lipids Synthesized by Type III Polyketide Synthases, Akimasa Miyanaga, Yasuo Ohnishi,

Pages 139-149 Lipid A, Russell E. Bishop, Pages 151-162 Lipoteichoic Acid Synthesis and Function in Gram-Positive Bacteria, Olaf Schneewind, Dominique

Missiakas, Pages 163-180 Mycolic Acids: From Chemistry to Biology, Mamadou Daffé, Annaïk Quémard, Hedia Marrakchi,

Pages 181-216 Lipid Intermediates in Bacterial Peptidoglycan Biosynthesis, Hélène Barreteau, Didier Blanot,

Dominique Mengin-Lecreulx, Thierry Touzé, Pages 217-235 Marinobacter as a Model Organism for Wax Ester Accumulation in Bacteria, Carolann M. Knutson,

Eric M. Lenneman, Brett M. Barney, Pages 237-258 Vitamin Formation from Fatty Acid Precursors, Michael F. Dunn, Pages 259-271 Functional Roles of Non-membrane Lipids in Bacterial Signaling, María J. Soto, N. Calatrava-

Morales, Isabel M. López-Lara, Pages 273-289

Formation of Lipochitin Oligosaccharide Signaling Molecules, V. Poinsot, F. Couderc, Pages 291-313

Metabolism and Regulation of Glycerolipids in Yeast, Vanina Zaremberg, Suriakarthiga Ganesan, Brittney N. Shabits, Pages 315-339

Metabolism and Roles of Sphingolipids in Yeast Saccharomyces cerevisiae, Jihui Ren, Yusuf A. Hannun, Pages 341-361

Nonpolar Lipids in Yeast: Synthesis, Storage, and Degradation, Karin Athenstaedt, Pages 363-373 Modeling Lipid Metabolism in Yeast; Eduard J. Kerkhoven, Pages 375-388 Genetics and Functional Genomics of Biogenesis of Fatty Acids and LipidsFatty Acid Synthesis and Regulation, Isabel M. López-Lara, María J. Soto, Pages 391-407 Components and Key Regulatory Steps of Lipid Biosynthesis in Actinomycetes, Gabriela Gago, Ana

Arabolaza, Lautaro Diacovich, Hugo Gramajo, Pages 409-433 Type III Polyketide Synthases Responsible for Phenolic Lipid Synthesis, Akimasa Miyanaga, Yasuo

Ohnishi, Pages 435-443 Wax Ester and Triacylglycerol Biosynthesis in Bacteria, H. M. Alvarez, M. A. Hernández, O. M.

Herrero, M. P. Lanfranconi, R. A. Silva, M. S. Villalba, Pages 445-456 Biogenesis of Medium-Chain-Length Polyhydroxyalkanoates, Ryan Kniewel, Olga Revelles Lopez,

M. Auxiliadora Prieto, Pages 457-481 Storage of Hydrophobic Polymers in Bacteria, Luísa S. Serafim, Ana M. R. B. Xavier, Paulo C.

Lemos, Pages 483-507 Players in the Nonpolar Lipid Game: Proteins Involved in Nonpolar Lipid Metabolism in Yeast,

Karin Athenstaedt, Pages 509-522 Biochemistry of Biogenesis of MembranesMembrane Lipid Biogenesis, Howard Goldfine, Pages 525-538 Biosynthesis and Evolution of Archaeal Membranes and Ether Phospholipids, Yosuke Koga, Pages

539-552 Functional Roles of Individual Membrane Phospholipids in Escherichia coli and Saccharomyces

cerevisiae, William Dowhan, Mikhail Bogdanov, Eugenia Mileykovskaya, Heidi Vitrac, Pages 553-574

Bacterial Lipid Domains and Their Role in Cell Processes, Adrián F. Alvarez, Dimitris Georgellis, Pages 575-592

Outer Membrane Vesicles of Bacteria: Structure, Biogenesis, and Function, Armaity Nasarabadi, James E. Berleman, Manfred Auer, Pages 593-607

Flip-Flopping Membrane Proteins: How the Charge Balance Rule Governs Dynamic Membrane Protein Topology, Mikhail Bogdanov, Heidi Vitrac, William Dowhan, Pages 609-636

Lactose Permease: From Membrane to Molecule to Mechanism, Lan Guan, H. Ronald Kaback, Pages 637-649

Role of the BAM Complex in Outer Membrane Assembly, Fernando Navarro-Garcia, Pages 651-669 Structure: Function of Transmembrane Appendages in Gram-Negative Bacteria, Miguel Ángel Díaz-

Guerrero, Meztlli O. Gaytán, Bertha González-Pedrajo, Pages 671-689 Fatty Acid-Binding Proteins, a Family of Lipid Chaperones, Masato Furuhashi, Pages 691-706 Protein Lipidation, Elucidation by Chemical Proteomics, and Its Functional Roles, Gemma Triola,

Pages 707-728 Membrane-Disrupting Proteins, Jeremy H. Lakey, Gregor Anderluh, Pages 729-739 Modeling Lipid Membranes, Pouyan Khakbaz, Viviana Monje-Galvan, Xiaohong Zhuang, Jeffery B.

Klauda, Pages 741-759 Membrane HomeostasisMembrane Formation and Regulation, Megan E. Ericson, Charles O. Rock, Pages 763-773 Regulation of Membrane Lipid Homeostasis in Bacteria upon Temperature Change, M. C. Mansilla,

D. de Mendoza, Pages 775-786 Membrane Homeostasis in Bacteria upon pH Challenge, Christian Sohlenkamp, Pages 787-799

Contributions of Membrane Lipids to Bacterial Cell Homeostasis upon Osmotic Challenge, T. Romantsov, J. M. Wood, Pages 801-822

Membrane Homeostasis upon Nutrient (C, N, P) Limitation, F. Schubotz, Pages 823-847 Autophagy in Stationary Phase of Growth, José L. Aguilar-López, Soledad Funes, Pages 849-866

Gentzis, T., Carvajal-Ortiz, H., Tahoun, S.S., Deaf, A., Ocubalidet, S., 2019. Organic facies and hydrocarbon potential of the early-middle Albian Kharita Formation in the Abu Gharadig Basin, Egypt, as demonstrated by palynology, organic petrology, and geochemistry. International Journal of Coal Geology 209, 27-39.


During the past decades, exploration activities carried out in the Western Desert of Egypt by several oil companies revealed the oversimplified approach to the study of sedimentary basins in this region. The current study evaluates and discusses the palynology and palynofacies of the clastic succession of the Kharita Formation (Albian) in one of the most petroliferous, deep seated, fault controlled basins in the Western Desert of Egypt, the Abu Gharadig Basin. Although the focus is on the palynofacies association, the hydrocarbon potential of the Kharita Formation will also be addressed by means of organic petrology and Rock-Eval pyrolysis. Marine Cretaceous source rocks have generated substantial quantities of oil and gas in the Abu Gharadig rift Basin. Moreover, Abu Gharadig Basin is characterized by containing not only oil/gas generating source rocks but also reservoir rocks with appreciable porosities and permeabilities. Palynological, TOC/Rock-Eval pyrolysis, and vitrinite reflectance (VRo%) data from 26 cuttings samples recovered from the Kharita Formation in the BED 2-1× well, are presented. The palynological age dating (AL-2 Palynozone) confirmed early to middle Albian age based on the first downhole appearance of the marker Concavisimisporites punctatus. The optical and visual characterization of the palynofacies associations showed two distinct palynofacies associations that alternated with each other. Kerogen type III to III/II was recorded based on the dominance of phytoclasts and opaque organics. Some intervals showed a slight dominance of amorphous organic matter (AOM). Thermal Alteration Index (TAI) values of 2+/3-measured on the psilate trilete spores, in combination with vitrinite reflectance (VRo) values in the range from 0.51 to 0.62%, and the yellow to dull-yellow colors of the liptinite macerals exhibited under UV light excitation indicate immature to the early stage of the oil window. Tmax values from Rock-Eval pyrolysis range from 426 to 438 °C also confirm the low maturity of the organic matter. Thin coal stringers were recorded within the Kharita Formation having slightly higher VRo,ran values (0.64 to 0.76%), which is possibly the result of differences in mineral matrix variations within the Kharita Formation. Based on the low TOC (avg. 0.71 wt%), S2 (avg. 0.97 mg HC/g rock), and HI (avg. 149 mg HC/g TOC) values from pyrolysis, the hydrocarbon potential of the Kharita Formation in the studied well is considered to be low.

Geraldi, N.R., Ortega, A., Serrano, O., Macreadie, P.I., Lovelock, C.E., Krause-Jensen, D., Kennedy, H., Lavery, P.S., Pace, M.L., Kaal, J., Duarte, C.M., 2019. Fingerprinting blue carbon: Rationale and tools to determine the source of organic carbon in marine depositional environments. Frontiers in Marine Science 6, 263. doi: 10.3389/fmars.2019.00263.


Blue carbon is the organic carbon in oceanic and coastal ecosystems that is captured on centennial to millennial timescales. Maintaining and increasing blue carbon is an integral component of strategies to mitigate global warming. Marine vegetated ecosystems (especially seagrass meadows, mangrove forests, and tidal marshes) are blue carbon hotspots and their degradation and loss worldwide have

reduced organic carbon stocks and increased CO2 emissions. Carbon markets, and conservation and restoration schemes aimed at enhancing blue carbon sequestration and avoiding greenhouse gas emissions, will be aided by knowing the provenance and fate of blue carbon. We review and critique current methods and the potential of nascent methods to track the provenance and fate of organic carbon, including: bulk isotopes, compound-specific isotopes, biomarkers, molecular properties, and environmental DNA. We find that most studies to date have used bulk isotopes to determine provenance, but this approach often cannot distinguish the contribution of different primary producers to organic carbon in depositional marine environments. Based on our assessment, we recommend application of multiple complementary methods. In particular, the use of carbon and nitrogen isotopes of lipids along with environmental DNA have a great potential to identify the source and quantify the contribution of different primary producers to sedimentary organic carbon in marine ecosystems. Despite the promising potential of these new techniques, further research is needed to validate them. This critical overview can inform future research to help underpin methodologies for the implementation of blue carbon focused climate change mitigation schemes.

Gerardo-Nieto, O., Vega-Peñaranda, A., Gonzalez-Valencia, R., Alfano-Ojeda, Y., Thalasso, F., 2019. Continuous measurement of diffusive and ebullitive fluxes of methane in aquatic ecosystems by an open dynamic chamber method. Environmental Science & Technology 53, 5159-5167.


An open dynamic chamber for the continuous monitoring of diffusive and ebullitive fluxes of methane (CH4) in aquatic ecosystems was designed and developed. This method is based on a standard floating chamber in which a well-defined carrier gas flows. The concentration of CH4 is measured continuously at the outlet of the chamber, and the flux is determined from a mass balance equation. The method was carefully tested in a laboratory and was subsequently applied to two lakes, in Mexico, with contrasting trophic states. We show here that the method allows for the continuous quantification of CH4 diffusive flux higher than 25 × 10–6 g m–2 h–1, the determination of ebullitive flux, and the individual characterization of bubbles larger than 1.50–1.72 mm in diameter. The method was also applied to determine carbon dioxide emissions (CO2). In that case, the method was less sensitive but allowed for the characterization of diffusive fluxes higher than 10 mg CO2 m–2 h–1 and of bubbles larger than 5.3–8.4 mm in diameter. This high-throughput method can be adapted to any gas detector at low cost, making it a convenient tool to better constrain greenhouse gas emission from freshwater ecosystems.

Gibbons, A., 2019. Ancient jaw gives elusive Denisovans a face. Science 364, 418-419.

http://science.sciencemag.org/content/364/6439/418.abstract

Thirty-nine years ago, a Buddhist monk meditating in a cave on the edge of the Tibetan Plateau found something strange: a human jawbone with giant molars. Now, almost 4 decades later, a groundbreaking new way to identify human fossils based on ancient proteins shows the jaw belonged to a Denisovan, a mysterious extinct cousin of Neanderthals. The jawbone is the first known fossil of a Denisovan outside of Siberia's Denisova Cave in Russia and gives paleoanthropologists their first real look at the face of this lost member of the human family. Together, the jaw's anatomy and the new method of analyzing ancient proteins could help researchers learn whether other mysterious fossils in Asia are Denisovans.

Gill, S., Catchpole, R., Forterre, P., 2019. Extracellular membrane vesicles in the three domains of life and beyond. FEMS Microbiology Reviews 43, 273-303.

https://doi.org/10.1093/femsre/fuy042

Cells from all three domains of life, Archaea, Bacteria and Eukarya, produce extracellular vesicles (EVs) which are sometimes associated with filamentous structures known as nanopods or nanotubes. The mechanisms of EV biogenesis in the three domains remain poorly understood, although studies in Bacteria and Eukarya indicate that the regulation of lipid composition plays a major role in initiating membrane curvature. EVs are increasingly recognized as important mediators of intercellular communication via transfer of a wide variety of molecular cargoes. They have been implicated in many aspects of cell physiology such as stress response, intercellular competition, lateral gene transfer (via RNA or DNA), pathogenicity and detoxification. Their role in various human pathologies and aging has aroused much interest in recent years. EVs can be used as decoys against viral attack but virus-infected cells also produce EVs that boost viral infection. Here, we review current knowledge on EVs in the three domains of life and their interactions with the viral world.

Giuranna, M., Viscardy, S., Daerden, F., Neary, L., Etiope, G., Oehler, D., Formisano, V., Aronica, A., Wolkenberg, P., Aoki, S., Cardesín-Moinelo, A., Marín-Yaseli de la Parra, J., Merritt, D., Amoroso, M., 2019. Independent confirmation of a methane spike on Mars and a source region east of Gale Crater. Nature Geoscience 12, 326-332.

https://doi.org/10.1038/s41561-019-0331-9

Reports of methane detection in the Martian atmosphere have been intensely debated. The presence of methane could enhance habitability and may even be a signature of life. However, no detection has been confirmed with independent measurements. Here, we report a firm detection of 15.5 ± 2.5 ppb by volume of methane in the Martian atmosphere above Gale Crater on 16 June 2013, by the Planetary Fourier Spectrometer onboard Mars Express, one day after the in situ observation of a methane spike by the Curiosity rover. Methane was not detected in other orbital passages. The detection uses improved observational geometry, as well as more sophisticated data treatment and analysis, and constitutes a contemporaneous, independent detection of methane. We perform ensemble simulations of the Martian atmosphere, using stochastic gas release scenarios to identify a potential source region east of Gale Crater. Our independent geological analysis also points to a source in this region, where faults of Aeolis Mensae may extend into proposed shallow ice of the Medusae Fossae Formation and episodically release gas trapped below or within the ice. Our identification of a probable release location will provide focus for future investigations into the origin of methane on Mars.

Godini, K., Samarghandi, M.R., Tahmasebi, H., Zarei, O., Karimitabar, Z., Yarahmadi, Z., Arabestani, M.R., 2019. Biochemical and molecular characterization of novel PAH-degrading bacteria isolated from polluted soil and sludge. Petroleum Science and Technology 37, 1763-1769.

https://doi.org/10.1080/10916466.2019.1575864

Polycyclic aromatic hydrocarbons (PAHs) containing more than three rings are mainly less biodegradable. Therefore, the isolation of PAHs-degrading bacteria is of great importance to be augmented for bioremediation of polluted sites with PAHs. PAHs-degrading bacteria were isolated from contaminated sites of an oil refinery. The strains were confirmed by biochemical tests and 16S

rRNA, which were Stenotrophomonas maltophilia (two strains), Thermomonas koreensis (three strains), Achromobacter (two strains), Pseudomonas stutzeri (one strain), Azospirillum brasilense (one strain) and Brevibacillus brevis (one strain). The isolate strains can be applied as a bacterial consortium for purification of polluted soil with high levels of PAHs.

Gómez-Robles, A., 2019. Dental evolutionary rates and its implications for the Neanderthal–modern human divergence. Science Advances 5, Article eaaw1268.

https://advances.sciencemag.org/content/5/5/eaaw1268

The origin of Neanderthal and modern human lineages is a matter of intense debate. DNA analyses have generally indicated that both lineages diverged during the middle period of the Middle Pleistocene, an inferred time that has strongly influenced interpretations of the hominin fossil record. This divergence time, however, is not compatible with the anatomical and genetic Neanderthal affinities observed in Middle Pleistocene hominins from Sima de los Huesos (Spain), which are dated to 430 thousand years (ka) ago. Drawing on quantitative analyses of dental evolutionary rates and Bayesian analyses of hominin phylogenetic relationships, I show that any divergence time between Neanderthals and modern humans younger than 800 ka ago would have entailed unexpectedly rapid dental evolution in early Neanderthals from Sima de los Huesos. These results support a pre–800 ka last common ancestor for Neanderthals and modern humans unless hitherto unexplained mechanisms sped up dental evolution in early Neanderthals.

González Martínez, M., Ohra-aho, T., Tamminen, T., da Silva Perez, D., Campargue, M., Dupont, C., 2019. Detailed structural elucidation of different lignocellulosic biomass types using optimized temperature and time profiles in fractionated Py-GC/MS. Journal of Analytical and Applied Pyrolysis 140, 112-124.


Fractionated pyrolysis coupled to gas chromatography and mass spectrometry experiments (Py-GC/MS) were carried out on eight woody and agricultural biomasses, including beech, poplar, pine forest residues, Scot Pine bark, reed canary grass, corn cob, grape seed cake and wheat straw. The selected temperature and duration for each fractionated pyrolysis step allowed separating the volatile pyrolysis products in function of their origin from biomass. As a result, carbohydrate derivatives from hemicelluloses were released at earlier fractionated pyrolysis steps, compared to those produced from cellulose degradation. Phenolic derivatives, mainly produced by lignin, were stepwise produced in function of the length and the nature of their side-chain substituents. Protein derivatives were also released in the whole Py-GC/MS temperature range. Macromolecular composition and biomass family were shown to play a crucial role in the thermal degradation of the biomasses of study. Production profiles exhibited resemblances per chemical species between deciduous and coniferous woods, while they appear to be more heterogeneous for agricultural biomasses. Herbaceous crops showed an intermediate behaviour between woods and agricultural biomasses.



Pore-fracture structure of shales is important to shale gas resource potential evaluation, exploration and development. However, investigations about the pore-fracture structure of shales were mainly focused on nano-submicron pores, while the contribution of micrometer-scaled pores and micro-fractures to pore system of shale reservoirs lack sufficient attention. Here, using a combination of field-emission scanning electronic microscopy (FE-SEM), gas adsorption (N2 and CO2) and CT scanning (Nano-CT and Micro-CT), the Longmaxi shale cored from JYA well, in the Fuling area, was selected to comprehensively evaluate the characteristics of the pore-fracture structure at different scales. The results show that there are diverse types of pores in the organic-rich shale, mainly consisted of organic pores, inorganic pores (interP pores and intraP pores) and micro-fractures. Many pores are ink bottle-shaped characterized by narrow necks and wide bodies, while some others are slit-shaped. Pore size range from 0.305 nm to 98.5 μm. Pores with diameter of 0.305–2 nm (micro-pores), 2–50 nm (meso-pores), 50 nm-2 μm (macro-pores) and 2–98.5 μm (micro-fractures) account for 33.59%, 36.28%, 14.04% and 16.09% of the total pore volume, respectively. Moreover, shale permeability and specific surface area were calculated to be 0.005 mD and 39.44 m2/g, respectively, based on the full-scaled pore splicing. About 92% of specific surface area is contributed by pores with diameter of 0.305–5 nm. Micro-fractures connect with each other and form net-shaped structure with great connectivity from observational results. The micro-fractures with size of 20–98.5 μm provide the main permeability (about 90%). Micro-pores and small meso-pores in shale reservoirs provide large adsorption space for adsorbed gas, while micro-fractures enhance the seepage capability of shale gas, which are favorable for shale gas accumulation.

Greber, N.D., Dauphas, N., 2019. The chemistry of fine-grained terrigenous sediments reveals a chemically evolved Paleoarchean emerged crust. Geochimica et Cosmochimica Acta 255, 247-264.


The nature of the rocks exposed to weathering and erosion on continents exerts an important control on weathering feedbacks and the supply of nutrients to the oceans. It also reflects the prevailing tectonic regime responsible for the formation of continents. How the chemical and lithological compositions of the continents evolved through time is, however, still a matter of debate. We use an extensive compilation of terrigenous sediment compositions to better constrain the nature of rocks at the surface of continents at 3.25 Gyr and 250 Myr ago. Specifically, we use geochemical ratios that are sensitive indicators of komatiite, mafic, and felsic rocks in the provenance of the sediments. Our results show that the average Al2O3/TiO2 ratio of fine-grained terrigenous sediments decreased slightly over time from 26.2 ± 1.3 in the Archean to 22.1 ± 1.1 (2SE) in the Phanerozoic. In contrast, in the same time interval, the average Zr/TiO2 ratio stayed nearly constant at ∼245. Considering the distinct behaviors of Al, Ti and Zr during sedimentary processes, we find that hydrodynamic mineral sorting had a minor effect on the chemical composition of Archean fine-grained sediments, but could have been more effective during periods of supercontinents. We show that the compositions of Phanerozoic sediments (Al2O3/TiO2, Zr/TiO2, La/Sc, Th/Sc, Ni/Co, Cr/Sc) are best explained with igneous rocks at the surface of continents consisting of 76 ± 8 wt% felsic, 14 ± 6 wt% Arc-basalts and 10 ± 2 wt% within-plate basalts, most likely in the form of continental flood basalts. Applying the same mass-balance calculations to the Paleoarchean suggests continental landmasses with 65 ± 7 wt% felsic, 25 ± 6 wt% mafic and 11 ± 3 wt% ultramafic rocks (all 2SE), likely in the form of komatiites. The presence of volumetrically abundant felsic rocks at the surface of continents (as evident from the sediment record) as well as at mid-crustal levels (as evident from presently exposed igneous rock record) in Paleoarchean cratons is currently best explained with the onset of subduction magmatism before 3.25 Gyr.

Greenwold, M.J., Cunningham, B.R., Lachenmyer, E.M., Pullman, J.M., Richardson, T.L., Dudycha, J.L., 2019. Diversification of light capture ability was accompanied by the evolution of phycobiliproteins in cryptophyte algae. Proceedings of the Royal Society B: Biological Sciences 286, 20190655.

https://doi.org/10.1098/rspb.2019.0655

Evolutionary biologists have long sought to identify phenotypic traits whose evolution enhances an organism's performance in its environment. Diversification of traits related to resource acquisition can occur owing to spatial or temporal resource heterogeneity. We examined the ability to capture light in the Cryptophyta, a phylum of single-celled eukaryotic algae with diverse photosynthetic pigments, to better understand how acquisition of an abiotic resource may be associated with diversification. Cryptophytes originated through secondary endosymbiosis between an unknown eukaryotic host and a red algal symbiont. This merger resulted in distinctive pigment–protein complexes, the cryptophyte phycobiliproteins, which are the products of genes from both ancestors. These novel complexes may have facilitated diversification across environments where the spectrum of light available for photosynthesis varies widely. We measured light capture and pigments under controlled conditions in a phenotypically and phylogenetically diverse collection of cryptophytes. Using phylogenetic comparative methods, we found that phycobiliprotein characteristics were evolutionarily associated with diversification of light capture in cryptophytes, while non-phycobiliprotein pigments were not. Furthermore, phycobiliproteins were evolutionarily labile with repeated transitions and reversals. Thus, the endosymbiotic origin of cryptophyte phycobiliproteins provided an evolutionary spark that drove diversification of light capture, the resource that is the foundation of photosynthesis.

Grohmann, S., Romero-Sarmiento, M.-F., Nader, F.H., Baudin, F., Littke, R., 2019. Geochemical and petrographic investigation of Triassic and Late Miocene organic-rich intervals from onshore Cyprus, Eastern Mediterranean. International Journal of Coal Geology 209, 94-116.


In order to improve the understanding of potential petroleum systems in the still underexplored Eastern Mediterranean Sea, two field campaigns were performed to investigate potential source rocks onshore Cyprus. Elemental data (total organic (TOC) and inorganic carbon (TIC), total sulfur (TS), Fe, Ni, V), Rock-Eval® pyrolysis, biomarker and microscopic analysis (organic petrography, random vitrinite reflectance (VRr), palynofacies) of the obtained Mesozoic to Cenozoic samples have proven the existence of organic matter (OM) rich deposits within the following two geological formations:

(1) The Triassic Vlambouros Formation (Fm.) of the Mamonia Complex comprises frequently occurring, few centimeter thin clay layers interbedded between meter thick sandstone units. The clay layers of this formation are characterized by TOC contents of about 1 wt% representing a Type III kerogen showing hydrogen index (HI) values of 48 mg HC/g TOC on average. VRr values of 0.5 to 0.6% as well as several biomarker ratios indicate low thermal maturity. The formation was deposited at the northern margin of Gondwana and similar strata may be present in the basement of the Levant Basin and the Eratosthenes Seamount. There, thermal maturity would be higher and such rocks might contribute to thermogenic gas systems.

(2) In the Miocene Pakhna Fm., OM-bearing intervals are mainly present in the upper part of the formation in outcrops east of the Troodos Mountain, while organic-rich intervals are very scarce to absent in the south and southwest of the island. The eastern outcrops show abundant fine-grained, (marly) mud- to wackestones interbedded with coarser-grained carbonates. The fine-grained intervals have TOC contents of about 4 wt% representing mainly Type II-III kerogen with HI values of 238 mg HC/g TOC on average. The OM is immature as indicated by VRr values between 0.3 and 0.5%.

TS/TOC ≥ 2.8 and several biomarker ratios indicate oxygen-depleted, even anoxic conditions during deposition. A negative correlation between the TOC and TIC indicates that such conditions were reached during enhanced primary bioproductivity controlled by local and regional clastic derived nutrient input. Similar conditions may have been present along the southeastern margin of the Eratosthenes Seamount, south of Cyprus. Presence of abundant organic matter and high sedimentation rates during the Miocene were favorable for microbial gas generation in the deeper parts of the basins.



As massive methane hydrate reservoirs in Shenhu slope area of northern South China, the structural-seepage hydrate-bearing sediments, which mainly include thick-bedded and disseminated types of hydrates, show favorable advantages of high content, great thickness, and excellent exploitation value. They are generated by thermogenic methane vertically migrated from deep strata through faults, and finally accumulate in shallow sand layers. In order to investigate the formation dynamics of massive methane hydrate reservoirs in Shenhu area, a vertical fluid flow-methane hydrate formation reaction-seafloor sedimentation model is designed to gauge the accumulation mechanism. From the analysis of Peclet number which weighs the relative importance between deposition and formation reaction, local methane hydrate looks more likely to actively gather together in the sediments primarily, then gradually evolve into massive reservoirs accompanying passive seafloor sedimentation. Through choosing three typical formation stages (50 ka, 3 Ma, and 5 Ma) to exhibit the evolution process of these hydrate reservoirs, the change of local pressures, temperatures, dissolved methane and salt, phase saturations, stratum permeability, and pore capillary pressure deduces how the structural-seepage hydrate reservoir operates. The investigation also shows that after 5 Ma theses hydrate-bearing layers can proceed to take on similar appearance with current occurrence when average seafloor sedimentation rate and the initial seafloor are 5 cm/ka and 988 m, respectively. Finally, the performance of five controlling factors, including methane flux, kinetic coefficient, initial fluid position, permeability and seafloor sedimentation rate, has been quantitatively assessed in this formation model. Our work verifies this methane hydrate formation reaction-seafloor sedimentation mechanism is adequate for studying Shenhu structural-seepage hydrate reservoirs. The findings further suggest the combination of small methane flux and small reaction coefficient should be preferentially recommended to breed this type of methane hydrate-bearing layers.

Gulliver, D., Lipus, D., Ross, D., Bibby, K., 2019. Insights into microbial community structure and function from a shallow, simulated CO2-leakage aquifer demonstrate microbial selection and adaptation. Environmental Microbiology Reports 11, 338-351.

https://doi.org/10.1111/1758-2229.12675

Geological carbon storage is likely to be a part of a comprehensive strategy to minimize the atmospheric release of carbon dioxide (CO2), raising concerns that injected CO2 will leak into overlying freshwater aquifers. CO2(aq) leakage may impact the dominant microbial community responsible for important ecosystem functions such as nutrient cycling, metal cycling and carbon conversion. Here, we examined the impact of an experimental in situ CO2‐leakage on a freshwater aquifer microbial community. High‐throughput 16S rRNA gene sequencing demonstrated lower microbial diversity in freshwater wells with CO2 concentrations above 1.15 g l−1. Metagenomic

sequencing and population genome binning were used to evaluate the metabolic potential of microbial populations across four CO2 exposed samples and one control sample. Population genome binning resulted in the recovery and annotation of three metagenome assembled genomes (MAGs). Two of the MAGs, most closely related to Curvibacter and Sulfuricurvum, had the functional capacity for CO2 utilization via carbon fixation coupled to sulfur and iron oxidation. The third draft genome was an Archaea, most closely related to Methanoregula, characterized by the metabolic potential for methanogenesis. Together, these findings show that CO2 leakage in a freshwater aquifer poses a strong selection, driving both microbial community structure and metabolic function.

Guo, C., Xia, Y., Ma, D., Sun, X., Dai, G., Shen, J., Chen, Y., Lu, L., 2019. Geological conditions of coalbed methane accumulation in the Hancheng area, southeastern Ordos Basin, China: Implications for coalbed methane high-yield potential. Energy Exploration & Exploitation 37, 922-944.

https://doi.org/10.1177/0144598719838117

The Hancheng area is a hot spot for coalbed methane exploration and exploitation in China. Structure is a key factor affecting coalbed methane accumulation and production in the Hancheng area. For a better understanding of the coalbed methane accumulation conditions and high-yield potential, this study investigates the structural patterns and evolution, the hydrogeological conditions, and the geothermal field in the coal-bearing strata in the Hancheng area. Then, the spatial distribution of the coalbed methane content and the tectonic deformation of the coal seam are evaluated. Finally, the critical depth for coalbed methane enrichment and a high-yield potential are revealed, and the favorable areas for coalbed methane development are predicted. The following conclusions are obtained: (1) Under the Yanshanian SE?NW trending maximum principle stress, the Hancheng overturned anticline was formed and subsequently subjected to uplift and erosion along its axis, which led to the NW limb of the anticline forming the current uniclinal structure of the Hancheng area; (2) Four degrees of tectonic deformation in the coal seam are identified based on structural curvature analysis. The moderately deformed area shallower than 800 m would benefit coalbed methane production with higher permeability. Most of the locations of coal and gas outburst events that occur during coal mining were distributed along the highly and very highly deformed areas; (3) The gas content gradually increases along the NW-trending inclination of the coal seam. 400 m and 800 m are discriminated as the critical depth levels for controlling coalbed methane accumulation and a high yield. Secondary biogenic methane was generated in the shallow formations; and (4) The Hancheng area is divided into four ranks for determining coalbed methane development potential. From high to low, they are ranked A, B-1, B-2, and C. Most of the high-yield wells are located in the areas ranked A and B-1.

Guo, P., Liu, C., Wang, L., Zhang, G., Fu, X., 2019. Mineralogy and organic geochemistry of the terrestrial lacustrine pre-salt sediments in the Qaidam Basin: Implications for good source rock development. Marine and Petroleum Geology 107, 149-162.


Terrestrial pre-salt sediments are not only good lithologic reservoirs similar to marine pre-salt carbonates, but also are supposed to have high hydrocarbon generation potential because the overlying terrestrial thick-bedded salts are generally preserved in basin centers. However, their status as source rock has attracted much less attention than as reservoir. In this paper, we choose the Qaidam Basin as an example and study the minerology, organic geochemistry, and organic petrology of the pre-salt sediments in a hydrocarbon-rich unit, where abundant petroleum resources have been discovered under halite beds. LithoScanner logging of six wells and X-ray diffraction results of 378

samples show that terrestrial pre-salt sediments are characterized by mixed siliciclastic-carbonate-sulphate rocks and their relative proportions are laterally varied. Quartz, feldspar and clay minerals are of allochthonous origin and classified as argillaceous endmember while dolomite and ankerite are of autochthonous origin as carbonate endmember. Organic geochemistry analysis of 118 samples show great variability in TOC, S2, and Tmax values, and this variability is not related to mineral composition heterogeneity as hydrogen index is not well correlated with detritus, carbonate, and sulphate minerals contents, indicating the interacting controls of source rocks by both exogenetic and endogenetic processes in brackish-mesosaline lakes. Strong bacterial reworking of organic matter results in the dominant macerals of pre-salt sediments as bituminite and oil generation at low maturity levels. Sealed by impermeable halite beds and in close proximity to reservoirs, the generating hydrocarbon by pre-salt good source rocks is effectively accumulated, which entails hydrocarbon exploration under halite beds in other terrestrial salt-bearing basins.

Guo, Q., Wang, S., Chen, X., 2019. Assessment on tight oil resources in major basins in China. Journal of Asian Earth Sciences 178, 52-63.


Large-scale commercial development of shale gas and tight oil resources in North American and continuous discoveries of tight oil in China lead to the recognition of the importance of assessment on tight oil resources. Based on the characteristics of China's tight oil reservoirs and exploration status, this paper discusses a workflow focusing on in-place resource evaluation. In the workflow, a Resource-Richness Analogy Approach (RR-AA) is proposed for assessment of tight oil resources in less explored areas, a Genesis-Statistics Assessment Approach (GS-AA) for lacustrine tight oil resources with strong heterogeneity and regions where more delicate assessment is required, and an EUR Analogy Approach (EUR-AA) for assessment on recoverable tight oil by fully using available EUR data of production wells. After analyzing the geological characteristics of the formation of tight oil in the Ordos, Bohai Bay, Songliao, Junggar, Sichuan and other major Basins, the distributions of essential parameters such as reservoir thickness, area and porosity have been defined, and the parameter evaluation criteria have been established. Finally, the tight oil resource potentials in the major basins in China have been evaluated using one of the three methods and the prospective areas of high resource abundance are outlined in each of basins. The results from this study show that China's tight oil resources have a large potential and good exploration future. The estimated in-place tight oil resources are 12.580 × 109 tons, mainly distributed in the Ordos, Songliao, Bohai Bay and Junggar Basins. 15 most favorable zones are proposed having in-place resources of 5.296 × 109 tons.

Guo, Q., Wu, N., Yan, W., Chen, N., 2019. An assessment method for deep gas resources. Acta Petrolei Sinica 40, 383-394.


In this study, a statistical analysis has been conducted on the reserve abundance of 365 natural gas reservoirs of more than 3500 m deep in China, which is mainly influenced by seven factors, i.e., reservoir lithology, effective reservoir thickness, porosity, gas saturation, burial depth, trap type and basin type. Accordingly, a multi-factor analog model is established to calculate out reserve abundance. In addition, based on the China’s database of calibrated areas for petroleum resource assessment and the drilling success rate of exploration wells in each oilfield over the years, the key parameters of assessment units are obtained using an analogy method, such as trap area coefficient, drilling success rate, effective trap area and oil bearing area coefficient of trap, so as to estimate the oil bearing area of each assessment unit. Finally, the operation flow and assessment effect of this

method are presented based on an application case, thus verifying its applicability and effectiveness. The proposal of this new method plays an active role in the potential evaluation of deep hydrocarbon resources at the present stage in China.

Guo, Y., Deng, W., Wei, G., Lo, L., Wang, N., 2019. Clumped isotopic signatures in land-snail shells revisited: Possible palaeoenvironmental implications. Chemical Geology 519, 83-94.


It is crucial to understand the clumped isotope compositions (Δ47) of modern land-snail shells and their relationship with environmental parameters for palaeoenvironmental-studies. Previous studies have shown significant variations in relationships between snail-shell Δ47 and ambient air temperature, and the reliability of shell Δ47 in indicating air temperature remains uncertain. This study examined the shell Δ47 from China with mean annual temperatures ranging from 5 to 23 °C and the snail body fluid δ18O estimated from shell δ18O and Δ47-derived temperatures. For all snails studied in this study, site-averaged Δ47 values yield snail calcification temperatures ranging from 25 to 36 °C, which are higher-than-expected in either environmental temperatures or estimated snail activity temperatures. We suggest that snails up-regulate their body temperatures towards their preferred living conditions likely through behaviour or/and physiology adaptation, especially at low temperature environments, which is likely significant than observed previously. Δ47 disequilibrium associated with CO2 degassing during snail calcification is potential but it could possibly be corrected by using an empirical calibration based on natural land-snails. Varying degrees of δ18O enrichment (>8‰) relative to rainwater are observed in snail body fluids, possibly due to variable evaporation during shell calcification. Coupled with model calculations, the relationship between snail body fluid δ18O and rainwater δ18O could be improved by using Δ47-based temperature and δ18O thermometry, if snails prefer to be active at ~90% relative humidity. This study highlights the importance of land-snail shell Δ47 coupled with shell δ18O to indicate temperature and rainwater δ18O at micro-environments scales.

Guo, Z., Pan, S., Liu, T., Zhao, Q., Wang, Y., Guo, N., Chang, X., Liu, T., Dong, Y., Yin, Y., 2019. Bacillus subtilis inhibits Vibrio natriegens-induced corrosion via biomineralization in seawater. Frontiers in Microbiology 10, 1111. doi: 10.3389/fmicb.2019.01111.


The marine bacterium, Vibrio natriegens, grows quickly in a marine environment and can significantly accelerate the corrosion of steel materials. Here, we present an approach to inhibit Vibrio natriegens-induced corrosion by biomineralization. The corrosion of steel is mitigated in seawater via the formation of a biomineralization induced by Bacillus subtilis. The film is composed of extracellular polymeric substances and calcite, exhibiting stable anti-corrosion activity. The microbial diversity and medium chemistry tests demonstrated that the inhibition of V. natriegens growth by B. subtilis was essential for the formation of the biomineralized film.

Gyr, L., Klute, F.D., Franzke, J., Zenobi, R., 2019. Characterization of a nitrogen-based dielectric barrier discharge ionization source for mass spectrometry reveals factors important for soft ionization. Analytical Chemistry 91, 6865-6871.


Atmospheric pressure plasma-based ionization coupled to mass spectrometry is a powerful analytical technique. However, the characteristics of existing ionization sources, especially regarding the reactive species and the effect of the discharge type on the soft ionization, are often not well described. In this work, the active capillary plasma ionization source, which is based on a dielectric barrier discharge, was characterized by optical emission spectroscopy and mass spectrometry. To obtain a better understanding of the requirements for a soft ionization, several reactive species and the energy of the ionization reaction were identified. Charged reactive species such as H3O+, N2

+•, N2H+, NO+, N3

+, and N4+• as well as uncharged species (most probably the excited neutral nitrogen) were all

found to contribute to the soft ionization process in dielectric barrier discharge. The energy in the plasma was determined to be in the range from 8 to 16 eV, based on the ionization energy of nitrogen and the measurements of tungsten hexacarbonyl. Furthermore, not only was the type of reactive species relevant for achieving a soft ionization, it was also crucial that the sample was injected through the inner electrode, which leads to nearly no direct contact with the discharge filaments.

Hakimi, M.H., Abdullah, W.H., Hersi, O.S., Lashin, A.A., El Alfy, M.M., Makeen, Y.M., Kinawy, M.M., Hatem, B.A., 2019. Organic geochemistry of the Early Cretaceous shales, Saar Formation in the East Shabwah oil fields, onshore Masila Basin of eastern Yemen. Journal of Petroleum Science and Engineering 179, 394-409.


The early Cretaceous Saar Formation includes potential petroleum-bearing source rocks in the onshore Masila Basin, eastern Yemen. The organic matter input, depositional environment conditions and petroleum generation potential from the Saar Formation shales were investigated using geochemical and organic petrological methods.

The shales of the Saar Formation contain total organic carbon of 0.5–3.5 wt percent. The geochemical analysis of the organic matter indicated that these shales have fair to very good hydrocarbon source potential. The kerogen of the organic matter is dominated by Type II/III and Type III, referring to both oil- and gas-prone source rocks. The biomarker and bulk carbon isotope analyses of the organic matter suggested that the kerogens were constituted from a combination of marine and high land plant organic matter, and were preserved under suboxic depositional conditions.

The geochemical and petrographic analyses of the shales (e.g., vitrinite reflectance (VRo), pyrolysis Tmax and biomarker maturity ratios) lead to the conclusion that the shales are generally immature to very early mature, particularly in shallower locations where the thermal alteration level of the organic matter is not strong enough to generate petroleum. Therefore, this work suggests that the mature source shale intervals of the Saar Formation existed in the deeper parts of the basin could reach a good maturity level that can produce potential hydrocarbons. Prediction of the potential migration pathways for hydrocarbons produced by deep shales could significantly aid in the future of petroleum exploration in the Masila Basin of Eastern Yemen.

Hakimi, M.H., Alaug, A.S., Lashin, A.A., Mohialdeen, I.M.J., Yahya, M.M.A., Kinawy, M.M., 2019. Geochemical and geological modeling of the Late Jurassic Meem Shale Member in the Al-Jawf sub-basin, Yemen: Implications for regional oil and gas exploration. Marine and Petroleum Geology 105, 313-330.


The Late Jurassic Meem Shale Member is widely exposed within the Sabatayn Basin, including in the Al-Jawf sub-basin. In this study, a total of 49 shale samples of the Meem Shale Member from two exploratory wells; Dahmar Ali−01 (28 samples in the depth range 1441–2351 m) and Kamaran-01 (21 samples in the depth range 2275–3011 m) in the south-eastern portion of the Al-Jawf sub-basin were studied as possible source rocks. Evaluation of source rock geochemistry including total organic matter (TOC) and Rock-Eval pyrolysis analyses was performed. The results of this study provided information regarding significant exploration of oil and gas resources from the Meem Shale Member in the Al-Jawf sub-basin.

Both the incident light microscopic results and the Rock-Eval geochemical study have indicated that the analyzed shale samples contain predominantly Type III kerogen with minor contributions of Type I/II and IV, so as to they can generate both oil and gas. The values of hydrogen index (HI) are decreased with increasing thermal maturity and varied between 34 and 803 mg HC/g TOC. Based on the measured VRo% range of 0.63 and 2.00, the Meem shales are currently within the oil- and gas-generation window, thus, they are considered as shale-oil and -gas resource possible plays.

The geochemical results were integrated with geological data of the Al-Jawf sub-basin and incorporated into a basin model to simulate petroleum generation and/or retention in the Meem Shale Member. The constructed basin models illustrated that the Meem Shale Member displayed a peak oil generation window during the Late Jurassic to Early Miocene, where large amounts of oil were generated, with a conversion ratio of 10–75 TR%. Further, the high heating rates from local volcanic rocks from the Early Miocene till date have caused gas generation from both of the original Type III kerogen and from secondary cracking of retained oil in the Meem Shale Member. However, the main contribution of gas generation within the Meem Shale Member came from secondary cracking processes through geologic time. The good thickness (736–910 m) of the organically-rich, high genetic potential and matured Meem Shale Member is expected to provide large amounts of oil and gas within the south-eastern portion of Al-Jawf sub-basin. Therefore, the Al-Jawf sub-basin can be considered as a rich oil and gas exploration province.

Hammarlund, E.U., Loydell, D.K., Nielsen, A.T., Schovsbo, N.H., 2019. Early Silurian δ13Corg excursions in the foreland basin of Baltica, both familiar and surprising. Palaeogeography, Palaeoclimatology, Palaeoecology 526, 126-135.


The Sommerodde-1 core from Bornholm, Denmark, provides a nearly continuous sedimentary archive from the Upper Ordovician through to the Wenlock Series (lower Silurian), as constrained by graptolite biostratigraphy. The cored mudstones represent a deep marine depositional setting in the foreland basin fringing Baltica and we present high-resolution data on the isotopic composition of the section's organic carbon (δ13Corg). This chemostratigraphical record is correlated with previously recognized δ13C excursions in the Upper Ordovician–lower Silurian, including the Hirnantian positive isotope carbon excursion (HICE), the early Aeronian positive carbon isotope excursion (EACIE), and the early Sheinwoodian positive carbon isotope excursion (ESCIE). A new positive excursion of high magnitude (~4‰) is discovered in the Telychian Oktavites spiralis Biozone (lower Silurian) and we name it the Sommerodde Carbon Isotope Excursion (SOCIE). The SOCIE appears discernible in δ13Ccarb data from Latvian and Estonian cores but it is not yet widely recognized. However, the magnitude of the excursion within the deep, marine, depositional setting, represented by the Sommerodde-1 core, suggests that the SOCIE reflects a significant event. In addition, the chemostratigraphical record of the Sommerodde-1 core reveals the negative excursion at the transition from the Aeronian to Telychian stages (the ‘Rumba low’), and suggests that the

commencement of the EACIE at the base of the Demirastrites triangulatus Biozone potentially is a useful chemostratigraphical marker for the base of the Aeronian Stage.

Han, B., Zheng, L., Li, Q., Lin, F., Ding, Y., 2019. Evaluation of the diagnostic ratios of adamantanes for identifying seriously weathered spilled oils from simulated experiment and actual oil spills. Environmental Geochemistry and Health 41, 817-828.

https://doi.org/10.1007/s10653-018-0177-x

The composition and physical properties of spilled oil have great changes during the seriously weathering process. It brings great difficulties to the source identification of oil spill. So the stable and trustworthy diagnostic ratios (DRs) for accurate identification of severely weathered spilled oils are very important. The explosion of Sinopec pipeline happened on November 22, 2013 at Qingdao, China. Local beaches at Jiaozhou Bay were polluted by spilled oils. We have collected original spilled oil samples from an area free from human interference near the oil leakage point after the accident. Synchronized with actual beach weathering, laboratory experiments were conducted to simulate oil weathering for 360 days by using the collected original spilled oil samples. Based on t test and the repeatability limit method, 50 diagnostic ratios (DRs) of adamantanes were screened. Four DRs, namely 1,3-dimethyladamantane/total dimethyladamantane, 1-methyladamantane/(1-methyladamantane + 1,3-dimethyladamantane), dialkyl diamantane/total diamantane, and diamantane/(diamantane + dialkyl diamantane), have maintained remarkable stability during the simulated weathering experiments and field weathering process. These stable ratios can retain the characteristics of oil source during weathering. They are very beneficial to improve the accuracy of identifying the source of severely weathered oil and can be used as an effective supplement to existing index system for source identification.

Han, B., Zheng, L., Lin, F., 2019. Risk assessment and source apportionment of PAHs in surface sediments from Caofeidian Long Island, China. Marine Pollution Bulletin 145, 42-46.


Sediment samples were collected from Caofeidian Long Island, China to investigate the contamination level and distribution pattern of 16 polycyclic aromatic hydrocarbons (PAHs). Source identification and risk assessment were also performed on these PAHs. The distribution patterns and source identification results indicated that the PAHs in the survey area originated from coal, biomass, and petroleum combustion as well as the combination of these three processes. Although the concentration of fluorene in the sediment exceeded the ERL level in some sampling sites, the effect range low–effect range median ratio implied a relatively low level of toxicity in these sediments. Meanwhile, the mean effects range–median quotient indicated that the 16 PAHs in sediments from Caofeidian Long Island pose a low ecological risk.



In this work, the thermal behavior of Nong’an oil shale of China was investigated and its pyrolysate analyzed in order to provide optimal pyrolysis parameters for the oil shale in-situ pyrolysis pilot project. Through thermogravimetric analysis (TGA) it was noted that the main mass loss of oil shale was in the temperature range of 310–600 °C and the maximum mass loss temperature was 465 °C.

The retorting experiments showed that temperature had an important influence on shale oil yield and the maximum oil yield was obtained at 550 °C. The oil yield was reduced at higher temperatures, resulting in an increase in gas yield. According to the analysis of shale oil composition the high pyrolysis temperature could promote the formation of short-chain hydrocarbons. Meanwhile, more alkenes and aromatics and less heteroatomic compounds were found at high temperature. The long-chain hydrocarbons and heteroatomic compounds were proved to be secondary products decomposed at higher temperature. In addition, the results of nitrogen adsorption/desorption and scanning electron microscopy (SEM) indicated that the shale surface became more porous due to the decomposition of kerogen and more micro- and mesopores were found after the treatment at high temperature.

Hao, J., Sverjensky, D.A., Hazen, R.M., 2019. Redox states of Archean surficial environments: The importance of H2,g instead of O2,g for weathering reactions. Chemical Geology 521, 49-58.


Redox states of the Archean Eon have been constrained by various lines of evidence, including atmospheric, photochemical, and ecological models, mass-independent fractionations of sulfur isotopes, Fe-depletion of paleosols, and preservation of diagnostic detrital minerals. Although these lines of evidence present seemingly consistent upper limits on pO2,g, they are conceptually contradictory about the redox state of Archean surficial environments. Atmospheric, photochemical, and ecological modeling studies suggest weakly reducing environments under redox states represented by moderate H2,g levels. However, current interpretations of Fe-depletion in paleosols and the preservation of detrital minerals are based on low O2,g levels at which the reducing detrital minerals are thermodynamically unstable and survive because of slow kinetics of oxidative weathering. In this study, we show that under the redox state indicated by the Archean pH2,g range, Fe2+ and reducing Fe(II)-minerals are actually thermodynamically stable and have no tendency to be oxidized. We emphasize that pH2,g values are orders of magnitude higher than pO2,g in the Archean atmosphere and that H2,g and pO2,g are not in equilibrium. The redox states of Archean surface environments behave as though they were controlled by the more abundant H2 instead of the very low O2, as in modern anoxic basins. Weathering in this case should have involved non-redox acidic dissolution of Fe(II)-species or reductive reaction of Fe(III)-species. Fe(II)-depleted paleosols and the preservation of relatively reduced detrital minerals are natural consequences of their thermodynamic stabilities in the Archean Eon's reducing environments rather than slow kinetics of oxidizing reactions. After the appearance of oxygenic photosynthesis, probably in the middle/late Archean, locally oxygenated environments could have existed, while the atmosphere as a whole remained anoxic. The profile of redox states on the Archean surface seems to be a reverse analogue to the modern Earth. Although oxidizing dissolution of transition metals could happen in O2-oases, quick reduction of oxyanions by abundant reductants, such as aqueous Fe2+, Fe(II)-minerals, and H2, might have restricted riverine transport of oxyanions and potentially complicate the interpretation of signals of O2-whiffs in marine sediments.

Hao, X., Schilling, M.R., Wang, X., Khanjian, H., Heginbotham, A., Han, J., Auffret, S., Wu, X., Fang, B., Tong, H., 2019. Use of THM-PY-GC/MS technique to characterize complex, multilayered Chinese lacquer. Journal of Analytical and Applied Pyrolysis 140, 339-348.


Use of micro-destructive analytical techniques to explore the complex matrix composition, structure and lacquering techniques of multilayer lacquered objects has been the focus of many researchers. This work presents the results of a comprehensive investigation of the “Tixi” carved lacquer micro-

sample excavated from Zhejiang province in China (Song Dynasty, A.D. 960-A.D. 1279). Stereomicroscopy, EPMA-EDS, FTIR, μ-RS and THM-Py-GC/MS were used in a comprehensive study of the object. The results show that the structure of the lacquer body consists of one wooden body layer, one lacquer ash layer, one ground lacquer layer and four lacquer film pigment layers, which indicates that it has been lacquered for several times. The chemical composition analysis results show that the lacquer stucco layer was made from the ashes by“Wan lacquering” craft. The lacquer film was made up of pigment (soot (black layer), orpiment (yellow layer), cinnabar (red layer)), lacquer sap, heat-bodied tung oil and tannins (partial layer); the presence of the series of catechols, acid catechols, phenols, alkyl benzenes, and hydrocarbons in which each has a maximum side chain length of 17 carbons and the most abundant member has nine carbons clearly indicate the species of the lacquer tree was Rhus succedanea that produces laccol. “Tixi” carved craft was used to make different lacquer film pigment veins layers appear simultaneously to emerge its unique characteristics like “drifting clouds and flowing water”.

Hargitai, H.I., Gulick, V.C., Glines, N.H., 2019. Evolution of the Navua Valles region: Implications for Mars' paleoclimatic history. Icarus 330, 91-102.


The Navua Valles are comprised of a system of channels and valleys on the inner Northeastern rim of Hellas Basin, which is a 1500-km-long sloping terrain. Drainage systems and regional geology in this unique setting were not previously mapped in detail. We mapped this region using CTX (6 m/px) as the base map and assessed surface unit ages resulting from our crater counting. We found that the timing of the deposit-forming episodes in this region during the Hesperian and Early to Middle Amazonian largely correlated to active phases of the Hadriacus Mons volcanic center. We found evidence for several episodes of fluvial activity Hesperian to the Amazonian with declining intensity, and transitioning to ice-dominated processes. The channels in the Navua Valles region erode into deposits dating from the Noachian to Early Amazonian, including the Noachian highlands, Noachian to early Amazonian crater ejecta, and likely volcanic plains formed from the Hesperian to the Hesperian–Amazonian transition. Channels directly originating from Hadriacus Mons are younger, while precipitation-fed channels at larger distance from the volcanic center are older, indicating different triggers for fluvial activity. Crater counting results indicate that almost all channel floors were at least partially resurfaced during the Amazonian and that several channel deposits formed during the last 0.5 Gyr. Water pathways likely included surface channels, lakes, and subsurface flow. The Navua Valles channel system is discontinuous, and the number of terminal deposits (sink locations) is almost as high as the number of channel sources, which is unusual for valley networks elsewhere on Mars. Interior channels formed only in the major Navua channels, they are even more fragmented than their parent channels, but occur along their entire length. Channels and valley systems within the Navua Valles are potential targets for in situ astrobiological studies, as they could have provided potential habitats at least periodically, from the Late Hesperian to the Late Amazonian.

Harnett, E.M., Johns, D., Gardner, J., Finneran, K., Davis, H., Massarano, B., 2019. An integrated approach for delivering current astrobiology research to the general public. Astrobiology 19, 696-708.


This article describes a multifaceted approach to delivering results from current research in astrobiology to visitors at Pacific Science Center, along with the evaluated results of the impact of the work. Content was delivered by (1) training scientists to communicate effectively with the public, (2) providing the trained scientists with venues to engage with the public, and (3) creating two Science

on Sphere shows that highlight key tenants scientists are investigating, a hands-on activity to facilitate interactive learning, and a temporary exhibit that highlights current research on the topic. Evaluation of visitors who engaged with each element demonstrates that the content had a large impact on both the increase in knowledge of the visitors and the increase of interest in the topic.

Hassan, S.A., Abdalla, B.K., Mustafa, M.A., 2019. Addition of silica nano-particles for the enhancement of crude oil demulsification process. Petroleum Science and Technology 37, 1603-1611.

https://doi.org/10.1080/10916466.2019.1602634

Different chemical demulsifiers were added to heavy Fula crude oil samples (Balila, Sudan) in screen test with and without the addition of silica nanoparticles (NPs). Two particle sizes of 25 nm and 95 nm were investigated using three different concentrations of 30 ppm, 60 ppm and 90 ppm. The addition of silica nanoparticles resulted in a clear improvement in demulsification in most cases. An increase of 150% in water separation was achieved with the addition of 25 nm silica NP suspension in a volume ratio of 1:0.5 (chemical demulsifier to silica nanoparticles) at a concentration of 60 ppm.

Hazra, B., Karacan, C.Ö., Tiwari, D.M., Singh, P.K., Singh, A.K., 2019. Insights from Rock-Eval analysis on the influence of sample weight on hydrocarbon generation from Lower Permian organic matter rich rocks, West Bokaro basin, India. Marine and Petroleum Geology 106, 160-170.


Among the different Rock-Eval parameters, the hydrocarbons released under the S2 peak of Rock-Eval is of significance as it indicates the residual hydrocarbon content of the rock. Further, through its relationship with total organic carbon (TOC) content, it helps in calculating hydrogen indices (HI) which helps in understanding the type of organic matter present in a rock [HI= (S2/TOC)*100]. The present study documents the role of sample weight/amount used for analysis on the Rock-Eval S2 parameter for unconventional source-rock characterization. For the purpose of this study, a vitrain band sample type (manually isolated from a coal), a high-TOC shale sample type, and a carbonaceous shale sample type were analyzed at two different particle sizes (viz. 1 mm-500 μm and 212-75 μm) and different sample weights (5–15 mg for organic matter rich rocks and 30–60 mg for shale) using a Rock-Eval basic cycle (heating rate at 25 °C/min). Although S2 is reported as mg hydrocarbon (HC)/g rock, with increase in sample weight, an increase in hydrocarbons released under the S2 peak of Rock-Eval was observed for all three sample types for both the particle sizes. The observations were further validated using a Norwegian geochemical standard (JR-1). Further, all samples were reanalyzed by conducting pyrolysis experiments at a lower heating rate of 5 °C/min. The impact of sample weight on S2 and HI was observed to be more pronounced for the JR-1 standard (higher hydrocarbon yield) than the Van Krevelen Types III-IV organic matter-bearing rocks. It thus calls for interpreters to be aware of the influence of mass of organic matter on hydrocarbon generation, and to monitor the maximum S2 values of organic matter-bearing rocks, within the flame ionization detector (FID) detection limits. Further, it is recommended that for Type III organic matter-bearing rocks with TOC content>20 wt %, elemental analysis should be used to derive atomic H/C and O/C ratios for Van Krevelen diagram-based kerogen typing.



In this paper, the stratigraphic occurrence of n-alkanes (Cn) is investigated in three peat cores (Mildred, JPH4 and McMurray) from the ombrotrophic peatlands in northeastern Alberta, Canada, to determine their origin, biomass input, and paleoclimatic significance. The molecular composition of n-alkanes is dominated by the >C21 medium- to long-chain homologues, with a strong odd over even predominance. A number of n-alkane-based indices (e.g. predominant n-alkane, C23/C29, C23/(C27 + C31), Paq, ACL, and CPI), show changing conditions in the organic matter (OM) input from Sphagnum species or terrestrial vascular plants, which increasingly contributed upwards in the peat profiles, and through time. Paq and C23/(C27 + C31) proxies are similar in the three cores, and allow us to infer vegetation variations that coincide with the climate alternations of the Medieval Warm Period (MWP), Little Ice Age (LIA), and modern Recent Warming (RW). The utilization of ACL-ket and (C23 + C25)/(C27 + C29 + C31)-ket proxies, performed in comparison with n-alkane proxies, further support the biomarker-based reconstructions of paleoclimate variations over recent centuries. This study suggests that n-alkane homologues are sensitive to vegetation and climate changes and thus are reliable biomarkers for tracking past shifts in vegetation and climate variations in peat archives.

He, L., Chen, J., Liu, K., Zhu, X., Zhang, C., Li, W., Luo, G., Wang, Y., 2019. Geochemical characteristics and sources of natural gas in the northern Xihu Sag Natural Gas Industry 39, 53-62.

http://www.cngascn.com:81/ngi_wk/EN/abstract/abstract18797.shtml

The Xihu Sag in the East China Sea Basin is rich in natural gas resources, but the sources of its natural gas have always been controversial. The existing researches mostly adopt the source rock maturity for gas source correlation without any direct evidence. In this paper, the large- and medium-sized gas fields discovered in the northern Xihu sag in recent years were taken as the research objects. After compositions, carbon isotopes and light hydrocarbon compositions of the natural gas in this area were analyzed, the geochemical characteristics and genesis types of natural gas were studied systematically. Then, combined with the thermal evolution of source rocks and the carbon isotope of kerogen, the sources of natural gas were analyzed and its migration modes and pathways were discussed. And the following research results were obtained. First, the natural gas of Huagang Fm in the northern Xihu Sag is mainly coal-type gas, which is generated from humic kerogen via primary cracking. It is mainly dry gas in the central uplift and wet gas in the west subsag. Second, the maturity of the source rocks in this area gradually increases from the south to the north, resulting in a higher maturity of natural gas in the central uplift and a lower maturity of natural gas in the west subsag. Third, though the source rocks of the Huagang Fm and the lower Pinghu Fm have different contributions to the natural gas in the northern part of the Xihu Sag, the natural gas there is mainly derived from the coal-bearing source rocks of Pinghu Fm. Among them, the coal-bearing source rocks of the Huagang Fm in the central uplift are of higher maturity and contribute more to the natural gas in this area. Fourth, the natural gas in this area is characterized by vertical migration and fractionation. After the Longjing movement, the fault is reactivated and provides a favorable pathway for the upward migration of natural gas from Pinghu Fm and its lower formations.



Molecular dynamics (MD) simulation is quickly growing in popularity as a technique for understanding asphaltene aggregate structure and dynamics. However, verification of the results of

simulations against experimental data has, to date, been sparse. Here, we present total scattering data from Athabasca asphaltenes, as both a solid and dispersed at high concentrations in deuterated 1-methylnaphthalene. The advantage of total scattering is that the expected scattering can be calculated from knowledge of the atomic positions in the system of question, meaning that simulation and experiment can be directly compared. We find that the MD simulations for model monodisperse systems reproduce the general form of the scattering curves well, particularly for the slope and shape for the small-angle scattering curve of dispersed asphaltenes. However, we find a number of limitations in the MD techniques as commonly used in the literature; specifically, the size of the aggregates formed is considerably smaller than observed from the scattering data. We identify two main causes of this discrepancy, namely, the limited box size that can be reasonably simulated and the lack of molecular polydispersity.

Heiland, J.J., Geissler, D., Piendl, S.K., Warias, R., Belder, D., 2019. Supercritical-fluid chromatography on-chip with two-photon-excited-fluorescence detection for high-speed chiral separations. Analytical Chemistry 91, 6134-6140.


Herein, we present the first example of microchip-based supercritical-fluid chromatography (SFC). A microfluidic-glass-chip platform with pressure and temperature control for fast and efficient on-column injection is described. This enabled fast and efficient separation of chiral and achiral compounds within seconds and also employed two-photon-excitated-fluorescence detection. Peak shapes were highly regular and symmetric even for linear flow rates over the packed microchip column in a range of up to 20 mm·s–1.

Hennissen, J.A.I., Gent, C.M.A., 2019. Total organic carbon in the Bowland-Hodder Unit of the southern Widmerpool Gulf: a discussion. Journal of Petroleum Science and Engineering 178, 1194-1202.


This review of the article by Kenomore et al. (2017) on the total organic carbon (TOC) evaluation of the Bowland Shale Formation in the Widmerpool Gulf sub-basin (southern Pennine Basin, UK) reveals a number of deficiencies, rooted mostly in an inadequate appreciation of the local Carboniferous stratigraphy. Kenomore et al. use the ΔLog R, the ‘Passey’ method after Passey et al. (1990), to evaluate the TOC content in two boreholes in the Widmerpool Gulf: Rempstone 1 and Old Dalby 1. We show here that Kenomore and co-authors used maturity data, published by Andrews (2013), from different formations to calibrate their TOC models of the Bowland Shale Formation (Late Mississippian–Early Pennsylvanian); the Morridge Formation in Rempstone 1 and the Widmerpool Formation in Old Dalby 1. We contest that this gives viable TOC estimates for the Bowland Shale Formation and that because of the location of the boreholes these TOC models are not representative over the whole of the Widmerpool Gulf. The pyrite content of the mudstones in the Widmerpool Gulf also surpasses the threshold where it becomes an influence on geophysical well logs. Aside from these stratigraphic and lithologic issues, some methodological weaknesses were not adequately resolved by Kenomore and co-authors. No lithological information is available for the Rock-Eval samples used for the maturity calibration, which because of the interbedded nature of the source formations has implications for the modelling exercise. We recommend that more geochemical data from a larger array of boreholes covering a wider area, proximal and distal, of the basin are collected before any inferences on TOC are made. This is necessary in the complex Bowland Shale system where lithological changes occur on a centimetre scale and correlations between the different sub basins are not well understood.

Herrling, M.P., Lackner, S., Nirschl, H., Horn, H., Guthausen, G., 2019. Recent NMR/MRI studies of biofilm structures and dynamics, in: Webb, G.A. (Ed.), Annual Reports on NMR Spectroscopy. Academic Press, pp. 163-213.


Biofilm systems consist of complex microbial communities embedded in hydrated bio-macromolecules. These biological systems have been studied by diverse analytical techniques, among them by nuclear magnetic resonance and imaging. There are still open questions regarding structure and functionality. In this review, nuclear magnetic resonance approaches, especially in form of magnetic resonance imaging and diffusion modalities, are summarized with respect to insights into biofilm structure, diffusion and advection, i.e. mass transport. Furthermore, possibilities and limitations regarding metabolomics are recapitulated and analysed with respect to open research questions. Perspectives for biofilm research will be discussed from the point of view of current technical and methodical developments of nuclear magnetic resonance. The impact of the named nuclear magnetic resonance techniques will be reflected in the context of water treatment and biofilm development in porous media as well as in technical applications such as biofilm reactors and biofiltration.

Hippke, M., 2019. Interstellar communication. I. Maximized data rate for lightweight space-probes. International Journal of Astrobiology 18, 267-279.

https://doi.org/10.1017/S1473550417000507

Recent technological advances could make interstellar travel possible, using ultra-lightweight sails pushed by lasers or solar photon pressure, at speeds of a few per cent the speed of light. Obtaining remote observational data from such probes is not trivial because of their minimal instrumentation (gram scale) and large distances (pc). We derive the optimal communication scheme to maximize the data rate between a remote probe and home-base. The framework requires coronagraphic suppression of the stellar background at the level of 10−9 within a few tenths of an arcsecond of the bright star. Our work includes models for the loss of photons from diffraction, technological limitations, interstellar extinction and atmospheric transmission. Major noise sources are atmospheric, zodiacal, stellar and instrumental. We examine the maximum capacity using the ‘Holevo bound’ which gives an upper limit to the amount of information (bits) that can be encoded through a quantum state (photons), which is a few bits per photon for optimistic signal and noise levels. This allows for data rates of the order of bits per second per Watt from a transmitter of size 1 m at a distance of α Centauri (1.3 pc) to an earth-based large receiving telescope (E-ELT, 39 m). The optimal wavelength for this distance is 300 nm (space-based receiver) to 400 nm (earth-based) and increases with distance, due to extinction, to a maximum of ≈ 3 μm to the centre of the Galaxy at 8 kpc.



In this study, the effects of amphiphilic water-soluble components of crude oil and ionic composition of water were investigated on the wettability alteration of a carbonate surface. Four different types of saltwater, which are made up of NaCl, MgCl2, CaCl2, and Na2SO4, with 0.5 M ionic strength, besides

distilled water, were contacted with crude oil to be saturated with water-soluble components. The post-contact (after contact with crude oil) water properties were characterized by Fourier transform infrared spectroscopy, total organic carbon, and pH analyses. The results showed that some polar compounds of crude oil with basic and mostly acidic functional groups were transferred to saltwater and distilled water. Afterward, the oil-wet carbonate surface was soaked in both freshwater (not contacted with crude oil) and post-contact water, and their effects on the wettability of the surface were investigated through contact angle and scanning electron microscopy experiments. The results of the contact angle indicated that generally, soaking of the oil-wet carbonate surface in both freshwater and post-contact water altered the wettability of the carbonate surface toward more water-wetness. However, the presence of water-soluble components in post-contact water (except for Na2SO4 saltwater), significantly reduced its wettability alteration efficiency in comparison to freshwater. Similarly, when water contains the Ca2+ ion, the calcite surface could not be dissolved in the aqueous phase, and accordingly, wettability alteration would be seriously retarded in both freshwater and post-contact water. Moreover, several mechanisms may jointly contribute in wettability alteration of the carbonate surface, which include organic–ionic layer dissolution into the aqueous phase, dissolution of the calcite surface alongside its adsorbed amphiphilic compounds, expansion of the electrical double layer, pairing of the Mg2+ ion with surface-absorbed compounds, Mg2+ substitution for Ca2+ on the calcite surface, and interaction of cationic components with absorbed acidic compounds.

Hu, A., Shen, A., Wang, Y., Pan, L., Wang, Y., Hao, Y., Zhang, J., 2019. The geochemical characteristics and origin analysis of the botryoidal dolomite in the Upper Sinian Dengying Formation in the Sichuan Basin, China. Journal of Natural Gas Geoscience 4, 93-100.


Botryoidal dolomite has great value for petroleum exploration and has dominantly developed in the middle and lower part of Member II in the Sinian Dengying Formation in the Sichuan Basin. By means of analysis of the elemental content, strontium isotope, carbon and oxygen isotope and carbonate clumped isotope on four kinds of diagenetic textures of botryoidal dolomite, the origin of botryoidal dolomite is analyzed and described. It has been concluded that botryoidal dolomite developed from various types of cement in progressively filled cavities which were formed by supergene karstification. Also, this study reveals that it is crucial to find freshwater dissolution zones, buried dissolution zones and hydrothermal activity zones for the reservoir prediction in the Sinian Dengying Formation.

Huan, T.N., Dalla Corte, D.A., Lamaison, S., Karapinar, D., Lutz, L., Menguy, N., Foldyna, M., Turren-Cruz, S.-H., Hagfeldt, A., Bella, F., Fontecave, M., Mougel, V., 2019. Low-cost high-efficiency system for solar-driven conversion of CO2 to hydrocarbons. Proceedings of the National Academy of Sciences 116, 9735-9740.

http://www.pnas.org/content/116/20/9735.abstract

Significance: Carbon dioxide electroreduction may constitute a key technology in coming years to valorize CO2 as high value-added chemicals such as hydrocarbons and a way to store intermittent solar energy durably. Based on readily available technologies, systems combining a photovoltaic (PV) cell with an electrolyzer cell (EC) for CO2 reduction to hydrocarbons are likely to constitute a key strategy for tackling this challenge. However, a low-cost, sustainable, and highly efficient PV–EC system has yet to be developed. In this article, we show that this goal can be reached using a low-cost and easily processable perovskite photovoltaic minimodule combined to an electrolyzer device

using the same Cu-based catalysts at both electrodes and in which all energy losses have been minimized.

Abstract; Conversion of carbon dioxide into hydrocarbons using solar energy is an attractive strategy for storing such a renewable source of energy into the form of chemical energy (a fuel). This can be achieved in a system coupling a photovoltaic (PV) cell to an electrochemical cell (EC) for CO2 reduction. To be beneficial and applicable, such a system should use low-cost and easily processable photovoltaic cells and display minimal energy losses associated with the catalysts at the anode and cathode and with the electrolyzer device. In this work, we have considered all of these parameters altogether to set up a reference PV–EC system for CO2 reduction to hydrocarbons. By using the same original and efficient Cu-based catalysts at both electrodes of the electrolyzer, and by minimizing all possible energy losses associated with the electrolyzer device, we have achieved CO2 reduction to ethylene and ethane with a 21% energy efficiency. Coupled with a state-of-the-art, low-cost perovskite photovoltaic minimodule, this system reaches a 2.3% solar-to-hydrocarbon efficiency, setting a benchmark for an inexpensive all–earth-abundant PV–EC system.

Huang, H., Tang, J., Niu, Z., Giesy, J.P., 2019. Interactions between electrokinetics and rhizoremediation on the remediation of crude oil-contaminated soil. Chemosphere 229, 418-425.


An electrokinetics (EK)-enhanced phytoremediation system with ryegrass was constructed to remediate crude oil-polluted soil. The four treatments employed in this study included (1) without EK or ryegrass (CK-NR), (2) EK only (EK-NR), (3) ryegrass only (CK-R), and (4) EK and ryegrass (EK-R). After 30d of ryegrass growth, EK at 1.0 V·cm−1 with polarity reversal (PR-EK) was supplied for another 30 d. The electric current was recorded during remediation. The pH, electrical conductivity, total petroleum hydrocarbon content (TPH), 16S rDNA, functional genes of AlkB, Nah, and Phe, DGGE, and dehydrogenase activity in soil were measured. The physical-chemical indexes of the plant included the length, dry mass, and chlorophyll contents of the ryegrass. Results showed that EK-R removed 18.53 ± 0.53% of TPH, which was higher than that of other treatments (13.34–14.31%). Meanwhile, the values of 16S rDNA, AlkB, Nah, Phe, and dehydrogenase activity in the bulk soil of EK-R all increased. Further clustering analysis with numbers of genes and DGGE demonstrated that EK-R was similar to the ryegrass rhizosphere soils in both EK-R and CK-R, while the EK treatment of EK-NR was similar to that of CK-NR without EK and ryegrass. These results indicate that the PR-EK treatment used in this experiment successfully enlarged the existing scale of the rhizosphere microorganisms, improved microbial activity and enhanced degradation of TPH.

Huang, J., Jin, T., Chai, Z., Barrufet, M., Killough, J., 2019. Compositional simulation of fractured shale reservoir with distribution of nanopores using coupled multi-porosity and EDFM method. Journal of Petroleum Science and Engineering 179, 1078-1089.


Shale reservoir contains highly heterogenous pore systems due to the wide-range distributions of nanopores in shale matrix and hydraulic/natural fractures. To explicitly include pore size distribution in simulation of shale reservoir, a multi-porosity model is applied to subdivide the matrix into multiple continua based on experimental pore size data. Each continuum has its own pore size, porosity and permeability, as well as other petrophysical properties. Besides, the embedded discrete fracture model (EDFM) is coupled with multi-porosity model to describe the complex fractures networks with any angles and intersections. To evaluate effects of pore size distribution on

production, compositional simulation is conducted in a fractured shale reservoir using different number of continua in shale matrix. Simulation results show that the use of multiple continua results in lower oil and gas production. Different pressures, oil and gas saturations and compositions are observed in different continua. To further investigate the effects of distribution of nanopores, oil-gas capillary pressure is rigorously calculated in every continuum. The existence of large capillary pressure leads to different fluid properties in different size of nanopores. Moreover, capillary pressure reduces oil and gas recovery and alters compositions of residuals. The effects of capillary pressure are more significant in the low permeable continua due to smaller pore sizes.



The increasing volume of petroleum products being transported from the Canadian oil sands raises concerns of potential impacts of accidental oil discharges in-land. Understanding the adsorption behavior of petroleum on mineral surfaces is important for oil spill modeling and response. In this work, a comparison study is conducted to probe the interaction behaviors of two distinct petroleum products, diluted bitumen (DB) and conventional crude oil (CCO), with molecularly smooth mica surfaces (as a model mineral) in toluene solutions using a surface forces apparatus (SFA) and an atomic force microscope (AFM). It is observed that DB exhibits adsorption behavior distinct from that of CCO at the tested concentrations. At low concentrations of oil in toluene (e.g., 0.1 v/v%), the adsorbed DB film on mica is twice as thick as the CCO film on mica. Weak adhesion (<1 mN/m) is measured when separating two oil-adsorbed mica surfaces in toluene. Alternatively, when the concentration of oil is increased to 10 v/v%, the initial oil-film thickness is doubled for the two oils tested. Adhesion (∼10 mN/m) with long stretching or bridging (>70 nm) is observed in DB-toluene but not in CCO-toluene. The distinct adsorption behavior of DB is demonstrated to be mainly due to the high concentration of surface-active components, such as asphaltenes. The AFM imaging and Fourier-transform infrared spectroscopy results further support the SFA results. Our study provides fundamental insights into the adsorption and interaction behaviors of DB and CCO on mineral surfaces, with implications for predicting oil spill behavior and improving spill response measures.

Huang, W., Zeng, L., Pan, C., Xiao, Z., Zhang, H., Huang, Z., Zhao, Q., Yu, S., Xu, H., Chen, C., Liu, D., Liu, J., 2019. Petroleum generation potentials and kinetics of coaly source rocks in the Kuqa Depression of Tarim Basin, northwest China. Organic Geochemistry 133, 32-52.


Confined pyrolysis experiments (gold capsules) were performed to determine the yields and kinetic features for petroleum formation for seven coal samples with hydrogen index (HI) ranging from 57 to 278 mg HC/g TOC and maturities of 0.58–0.74 %Ro from coal pits within Triassic–Jurassic strata in the Kuqa Depression, China. Gases and liquid yields were measured at regular intervals as the sealed tubes were heated at 2 and 20 °C/h and total thermal stress calculated as a vitrinte reflectance equivalent (%Re) using Easy%Ro. The total confined pyrolysate yields of oil and gaseous hydrocarbons at 1.19–1.50 %Re only account for a portion (38–53%) of the releasable moieties in measured by Rock-Eval (open) pyrolysis, suggesting that a substantial portion of (47–62%) of these moieties was rearranged and incorporated into polyaromatic residual solids. At maturities >1.87 %Re, the solid residues of the seven coals have very similar gas generative potentials (ΣC1–5), which are substantially higher than their quality index (QI = (S1 + S2)/TOC) with differences ranging from 20 to 40 mg/g TOC. This result can be mainly ascribed to the differences both in methane formation

mechanisms and final thermal stress levels between open (2.25 %Re) and confined pyrolysis (4.44 %Re). Only a minor portion of gaseous hydrocarbons (∼32% and 44% for the Jurassic and Triassic coals, respectively) was generated up to 2.19 %Re while the major portion was generated at higher maturities. Under a heating rate of 5 °C/My, the Jurassic and Triassic coals are modeled to become effective gas source rocks with gas yield (ΣC1–5) > 20 mg/g TOC at maturities of >1.76 %Re and 1.59 %Re, respectively. The abundant gaseous hydrocarbons found in the Kuqa Depression can be mainly ascribed to the high maturities of coal source rocks (>2.0 %Ro), in combination with excellent seal of thick salt and gypsum for the gas reservoirs.


https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/2018PA003470

Past occurrences of widespread and severe anoxia in the ocean have frequently been associated with abundant geological evidence for free hydrogen sulfide (H2S) in the water column, so‐called euxinic conditions. Free H2S may react with, and modify, the chemical structure of organic matter settling through the water column and in marine sediments, with hypothesized implications for carbon sequestration. Here, taking the example of Ocean Anoxic Event 2, we explore the potential impact of organic matter sulfurization on marine carbon and oxygen cycling by means of Earth system modeling. Our model experiments demonstrate that rapid sulfurization (ksulf≥ = 105 M−1 year−1) of organic matter in the water column can drive a more than 30% enhancement of organic carbon preservation and burial in marine sediments and hence help accelerate climate cooling and Ocean Anoxic Event 2 recovery. As a consequence of organic matter sulfurization, we also find that H2S can be rapidly scavenged and the euxinic ocean volume reduced by up to 80%—helping reoxygenate the ocean as well as reducing toxic H2S emissions to the atmosphere, with potential implications for the kill mechanism at the end‐Permian. Finally, we find that the addition of organic matter sulfurization induces a series of additional feedbacks, including further atmospheric CO2 drawdown and ocean reoxygenation by the creation of a previously unrecognized net source of alkalinity to the ocean as H2S is scavenged and buried.

Hurai, V., Černušák, I., Randive, K., 2019. Hydrogen recovery from H2S-CH4 inclusions trapped in quartz triggered by green laser-induced photolysis of polysulphane-sulphur bonds. Applied Geochemistry 106, 75-81.


Natural H2S-CH4 inclusions enclosed in quartz were transformed into H2-CH4 mixture with none or negligible H2S concentration after short irradiation of associated sulphur daughter phase with 532 nm photons emitted by a 25 mW Nd-YAG laser. As much as 57 mol. % (73.8 wt %) H2S in the gas inclusions was converted to its constituent elements in sulphur-bearing inclusions. In contrast, the H2S splitting did not occur within the inclusions devoid of the sulphur daughter phase. Raman spectroscopic data and density functional theory-based calculations corroborated the existence and photolytic breakdown of sulphur-bound polysulphanes, which provided accelerated H⋅ radicals capable of breaking the stronger S-H bond in the surrounding molecular H2S at room temperature. The polysulphane-supported photolysis combines benefits of deactivation of the toxic and corrosive H2S pollutant with hydrogen and sulphur recovery, and as such it has a potential of utilizing for the environment-friendly processing and purification of the super-soar natural gas.



The Peruvian upwelling system (PUS) is among the most productive regions in the ocean, with high rates of primary production and an intense oxygen minimum zone (OMZ). The main perturbation of this system is associated to “El Niño” (EN), which affects water mass distribution and reduces primary production. Previous studies in the PUS provided first insights into the dynamics of dissolved organic matter (DOM), but high-resolution studies involving the molecular characterization of the DOM pool to reveal the processes that affect the carbon cycle in this highly productive system are lacking. We characterized the molecular composition of solid-phase extractable DOM (SPE-DOM) in the coastal upwelling system off Central Peru and linked it to specific processes that affect DOM cycling. Seasonal sampling (April, August and December) was carried out off Central Peru (12°S) during 2015, a low productivity year marked by EN conditions. The DOM molecular composition was obtained via Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR-MS). Solid-phase extractable dissolved organic carbon (SPE-DOC) concentrations showed significant differences (p<0.05) between the water masses present off central Peru. In order to explore if changes in SPE-DOC concentrations were the result of water mass mixing, we applied a conservative mixing model. The model revealed a non-conservative behaviour of SPE-DOC and allowed us to identify two distinct groups of samples with increased and decreased SPE-DOC concentrations respectively, and one group of samples inside the conservative mixing range. Differences in environmental parameters characterizing these groups were in accordance with respective processes associated to production and degradation of SPE-DOC. The trends observed for molecular parameters revealed the imprint of processes related to DOM production and DOM degradation, both biotic (microbial degradation) and abiotic (photodegradation). Our study suggests that even under low productivity conditions like EN, there is an active cycling of the DOM pool off central Peru.

Ismail, M., Yang, Y., Chaisoontornyotin, W., Ovalles, C., Rogel, E., Moir, M.E., Hoepfner, M.P., 2019. Effect of chemical inhibitors on asphaltene precipitation and morphology using ultra-small-angle X-ray scattering. Energy & Fuels 33, 3681-3693.


This paper presents time-resolved ultra-small-angle X-ray scattering (USAXS) results of the effect of chemical inhibitors, dodecylphenol (DDPh) and nonylphenol formaldehyde resin-1600 (NPFR), on the kinetic precipitation of asphaltenes. With length scale ranges probed between 1 nm and 5 μm, USAXS provides a unique means to simultaneously characterize insoluble asphaltene clusters with length scales of >50 nm and soluble clusters with length scales of <50 nm. Both inhibitors tested were observed to reduce the insoluble asphaltene growth rate at 500 and 5000 ppm (mg/kg) inhibitor concentrations, with DDPh displaying a relatively larger reduction. Further, both of the chemical inhibitors tested modified the morphology of insoluble asphaltenes, and the most effective inhibitor, DDPh, also reduced the size of soluble asphaltene clusters. The asphaltene sample used in this study initially precipitated as a fractal cluster that transitioned to a second liquid or solid phase with a rough surface. These insoluble particles further flocculate into larger mass fractals and are commonly visualized with optical microscopy. The chemical inhibitors slowed the rate of transition to a new phase, and the fractal geometry of the insoluble particles persisted for longer times. Consequently, USAXS is a new tool that can be used to better understand the impact of chemical inhibitors on the structure and dynamic aggregation of asphaltenes over broad length scales.


https://www.frontiersin.org/article/10.3389/feart.2019.00091

The exploration of Mars is largely based on comparisons with Earth analogue environments and processes. The up-coming NASA Mars mission 2020 and ExoMars 2020 has the explicit aim to search for signs of life on Mars. During preparations for the missions, glaring gaps in one specific field was pointed out: the lack of a fossil record in igneous and volcanic rock. Earth´s fossil record is almost exclusively based on findings in sedimentary rocks, while igneous rocks have been considered barren of life, including a fossil record of past life. Since martian volcanic rocks will be targeted in the search for biosignatures, the lack of a terrestrial analogue fossil record is an obvious impediment to the scientific aim of the mission. Here we will briefly review the knowledge of microscopic life in deep rock and deep time. Focus will be on underexplored environments in subseafloor crustal rocks, and on ancient environments harbouring early prokaryotic and eukaryotic lineages. We will highlight some of the aspects that need immediate attention and further investigations to meet the scientific goals of the missions. The current paper is a first step towards the long-term aim is to establish an atlas of the fossil record in volcanic rocks, which can be of use for the up-coming space missions.

Jacobson, M.Z., 2019. Short-term impacts of the Aliso Canyon natural gas blowout on weather, climate, air quality, and health in California and Los Angeles. Environmental Science & Technology 53, 6081-6093.


The Aliso Canyon (Porter Ranch), California, natural gas blowout lasted 112 days, from October 23, 2015 to February 11, 2016, releasing 97 100 metric tonnes of methane, 7300 tonnes of ethane, and a host of other hydrocarbons into the Southern California air. This study estimates the impacts of the leak on transient weather, climate, air quality, and health in California and the Los Angeles Basin using a nested global-through-local weather–climate–air quality computer model. Results suggest that the Aliso Canyon leak may have increased the mixing ratios of multiple emitted hydrocarbon gases throughout California. Subsequent gas-phase photochemistry increased the mixing ratios of additional byproducts, including carbon monoxide, formaldehyde, acetaldehyde, peroxyacetyl nitrate, and ozone. Increases in air temperatures aloft and lesser increases at the surface due to thermal-infrared radiation absorption by methane stabilized the air over much of California, slightly reducing clouds, precipitation, and near-surface wind speed with greater reductions in Los Angeles than in California. The reduction in precipitation, in particular, increased PM2.5 concentration, with a greater increase in Los Angeles than in California. The higher PM2.5 increased estimated premature mortality in California by +32 (9–54) to +43 (15–66), depending on the set of relative risks used. Despite higher PM2.5 in Los Angeles due to the leak, premature mortalities there were more ambiguous, ranging from a mean decrease of −7 to a mean increase of +15, for 2 simulations with different resolution and boundary conditions. The remaining mortalities occurred in the Central Valley and San Francisco Bay Area. Ozone premature mortalities away from the leak increased by <1. The study did not evaluate potential health impacts, including cancers, immediately near the leak. As such, the Aliso Canyon leak affected temperatures, pollution, and health throughout California. Future leaks will also likely have impacts.

Jafarabadi, A.R., Dashtbozorg, M., Bakhtiari, A.R., Maisano, M., Cappello, T., 2019. Geochemical imprints of occurrence, vertical distribution and sources of aliphatic hydrocarbons, aliphatic ketones,

hopanes and steranes in sediment cores from ten Iranian Coral Islands, Persian Gulf. Marine Pollution Bulletin 144, 287-298.

http://www.sciencedirect.com/science/article/pii/S0025326X1930373X

The levels, vertical distribution and sources of hydrocarbons and petroleum biomarkers were estimated for the first time in sediment cores (0–40 cm) from ten coral Islands of the Persian Gulf, Iran. Discrepant hydrocarbons, including linear n-alkanes (n-C11 to n-C40) and isoprenoids (AHs), aliphatic ketones (AKs), hopanes and steranes were measured in all core samples, showing mean concentrations ranging from 209 to 5388 μg g−1dw (∑30AH), 2–244 μg g−1-dw (∑13AK), 189–3713 ng g−1dw (∑31hopane) and 42–3864 ng g−1dw (∑15sterane), respectively. All sediment cores were found to be petroleum polluted, with ∑30AH > ∑31hopane > ∑15sterane > ∑13AK, with higher levels recorded at 10–20 cm, mainly at industrial sites. Various diagnostic indices revealed that hydrocarbons derived mainly from anthropogenic inputs, with significant contribution of biogenic origin at sites less polluted. Moreover, total organic carbon (0.24–23.45 mg g−1-dw), terrestrial and marine organic matter had an overwhelming effect on hydrocarbons deposition in sediment cores. Overall, findings provide relevant information for monitoring and preventing petroleum pollution in the sensitive ecosystems of the Persian Gulf.

Jain, C., Rozel, A.B., Tackley, P.J., Sanan, P., Gerya, T.V., 2019. Growing primordial continental crust self-consistently in global mantle convection models. Gondwana Research 73, 96-122.


The majority of continental crust formed during the hotter Archean was composed of Tonalite-Trondhjemite-Granodiorite (TTG) rocks. In contrast to the present-day loci of crust formation around subduction zones and intra-plate tectonic settings, TTGs are formed when hydrated basalt melts at garnet-amphibolite, granulite or eclogite facies conditions. Generating continental crust requires a two step differentiation process. Basaltic magma is extracted from the pyrolytic mantle, is hydrated, and then partially melts to form continental crust. Here, we parameterise the melt production and melt extraction processes and show self-consistent generation of primordial continental crust using evolutionary thermochemical mantle convection models. To study the growth of TTG and the geodynamic regime of early Earth, we systematically vary the ratio of intrusive (plutonic) and eruptive (volcanic) magmatism, initial core temperature, and internal friction coefficient. As the amount of TTG that can be extracted from the basalt (or basalt-to-TTG production efficiency) is not known, we also test two different values in our simulations, thereby limiting TTG mass to 10% or 50% of basalt mass. For simulations with lower basalt-to-TTG production efficiency, the volume of TTG crust produced is in agreement with net crustal growth models but overall crustal (basaltic and TTG) composition stays more mafic than expected from geochemical data. With higher production efficiency, abundant TTG crust is produced, with a production rate far exceeding typical net crustal growth models but the felsic to mafic crustal ratio follows the expected trend. These modelling results indicate that (i) early Earth exhibited a “plutonic squishy lid” or vertical-tectonics geodynamic regime, (ii) present-day slab-driven subduction was not necessary for the production of early continental crust, and (iii) the Archean Earth was dominated by intrusive magmatism as opposed to “heat-pipe” eruptive magmatism.

Jamali, A., Vinhal, A.P.C.M., Behnejad, H., Yan, W., Kontogeorgis, G.M., 2019. Comparison of two crossover procedures for describing thermodynamic behavior of normal alkanes from singular critical to regular classical regions. Fluid Phase Equilibria 495, 33-46.


In this work, two crossover procedures were applied to the Soave-Redlich-Kwong (SRK) equation of state (EoS) in order to describe the thermodynamic behavior of hydrocarbons from far away up to close to the critical point. The first one is based on a renormalization group theory method, which uses a recursive procedure originally proposed by White and coworkers (Salvino and White, J. Chem. Phys. 96 (1992) 4559–4568). The second one incorporates the scaling laws close to the critical point into the cubic EoS, and was developed by Kiselev (Kiselev, Fluid Phase Equilibria, 147 (1998) 7–23). The classical and crossover SRK EoS are applied to describe the phase behavior of pure n-alkanes (from methane to n-decane), and the comparison with experimental data indicates that the non-mean-field models are superior to the classical one for the representations of vapor-liquid coexistence data, isothermal pressure-density data and critical properties. Additionally, a thorough comparison of the two crossover approaches is done indicating the advantages and disadvantages of each approach.

James, K.L., Kung, J.W., Crable, B.R., Mouttaki, H., Sieber, J.R., Nguyen, H.H., Yang, Y., Xie, Y., Erde, J., Wofford, N.Q., Karr, E.A., Loo, J.A., Ogorzalek Loo, R.R., Gunsalus, R.P., McInerney, M.J., 2019. Syntrophus aciditrophicus uses the same enzymes in a reversible manner to degrade and synthesize aromatic and alicyclic acids. Environmental Microbiology 21, 1833-1846.

https://doi.org/10.1111/1462-2920.14601

Syntrophy is essential for the efficient conversion of organic carbon to methane in natural and constructed environments, but little is known about the enzymes involved in syntrophic carbon and electron flow. Syntrophus aciditrophicus strain SB syntrophically degrades benzoate and cyclohexane‐1‐carboxylate and catalyses the novel synthesis of benzoate and cyclohexane‐1‐carboxylate from crotonate. We used proteomic, biochemical and metabolomic approaches to determine what enzymes are used for fatty, aromatic and alicyclic acid degradation versus for benzoate and cyclohexane‐1‐carboxylate synthesis. Enzymes involved in the metabolism of cyclohex‐1,5‐diene carboxyl‐CoA to acetyl‐CoA were in high abundance in S. aciditrophicus cells grown in pure culture on crotonate and in coculture with Methanospirillum hungatei on crotonate, benzoate or cyclohexane‐1‐carboxylate. Incorporation of 13C‐atoms from 1‐[13C]‐acetate into crotonate, benzoate and cyclohexane‐1‐carboxylate during growth on these different substrates showed that the pathways are reversible. A protein conduit for syntrophic reverse electron transfer from acyl‐CoA intermediates to formate was detected. Ligases and membrane‐bound pyrophosphatases make pyrophosphate needed for the synthesis of ATP by an acetyl‐CoA synthetase. Syntrophus aciditrophicus, thus, uses a core set of enzymes that operates close to thermodynamic equilibrium to conserve energy in a novel and highly efficient manner.


https://www.clim-past.net/15/849/2019/

Past changes in the inventory of carbon stored in vegetation and soils remain uncertain. Earlier studies inferred the increase in the land carbon inventory (Δland) between the Last Glacial Maximum (LGM) and the preindustrial period (PI) based on marine and atmospheric stable carbon isotope reconstructions, with recent estimates yielding 300–400 GtC. Surprisingly, however, earlier studies considered a mass balance for the ocean–atmosphere–land biosphere system only. Notably, these studies neglect carbon exchange with marine sediments, weathering–burial flux imbalances, and the

influence of the transient deglacial reorganization on the isotopic budgets. We show this simplification to significantly reduce Δland in simulations using the Bern3D Earth System Model of Intermediate Complexity v.2.0s. We constrain Δland to ∼850 GtC (median estimate; 450 to 1250 GtC ±1SD) by using reconstructed changes in atmospheric δ13C, marine δ13C, deep Pacific carbonate ion concentration, and atmospheric CO2 as observational targets in a Monte Carlo ensemble with half a million members. It is highly unlikely that the land carbon inventory was larger at LGM than PI. Sensitivities of the target variables to changes in individual deglacial carbon cycle processes are established from transient factorial simulations with the Bern3D model. These are used in the Monte Carlo ensemble and provide forcing–response relationships for future model–model and model–data comparisons. Our study demonstrates the importance of ocean–sediment interactions and burial as well as weathering fluxes involving marine organic matter to explain deglacial change and suggests a major upward revision of earlier isotope-based estimates of Δland.

Ji, H., Xu, Y., Lu, H., Zhang, Z., 2019. Deep MS/MS-aided structural-similarity scoring for unknown metabolite identification. Analytical Chemistry 91, 5629-5637.


Tandem mass spectrometry (MS/MS) is the workhorse for structural annotation of metabolites, because it can provide abundance of structural information. Currently, metabolite identification mainly relies on querying experimental spectra against public or in-house spectral databases. The identification is severely limited by the available spectra in the databases. Although, the metabolome consists of a huge number of different functional metabolites, the whole metabolome derives from a limited number of initial metabolites via bioreactions. In each bioreaction, the reactant and the product often change some substructures but are still structurally related. These structurally related metabolites often have related MS/MS spectra, which provide the possibility to identify unknown metabolites through known ones. However, it is challenging to explore the internal relationship between MS/MS spectra and structural similarity. In this study, we present the deep-learning-based approach for MS/MS-aided structural-similarity scoring (DeepMASS), which can score the structural similarity of unknown metabolite against the known one with MS/MS spectra and deep neural networks. We evaluated DeepMASS with leave-one-out cross-validation on MS/MS spectra of 662 compounds in KEGG and an external test on the biomarkers from male infertility study measured on Shimadzu LC-ESI-IT-TOF and Bruker Compact LC-ESI-QTOF. Results show that the identification of unknown compound is valid if its structure-related metabolite is available in the database. It provides an effective approach to extend the identification range of metabolites for existing MS/MS databases.



Owing to the presence of multiscale pore structures, characterization of laminated shales is both extremely difficult and substantially different from that of conventional reservoirs, and defies conventional methodologies. In this paper, a multiscale reconstructing method for shale is proposed to generate 3D layer representative elementary volume (lREV)-scale digital-experimental models to characterize the multiscale pore structure of the shale by means of the combination of a large area SEM image, nitrogen adsorption and pressure pulse decay experiment result. In this method an improved multiscale superposition algorithm is introduced to integrate the reconstructed complex models from nanoscale to mesoscale together, and it can preserve the details and main features

enormously of each typical component (nanoscale organic pores in organic matter and pyrites, micro-nano inorganic pores and micro slits) in the shale. Especially, to accurately reproduce the realistic morphology for shale, the proposed method uses the experimental pore size distribution and permeability as constrain conditions to adjust and optimize the lREV-scale digital-experimental model. Our proposed method was tested on Longmaxi and Wufeng shale samples, and the reconstructed lREV-scale digital-experimental model are proved to accurately describe the representative structure of the complex multiscale pore space of the typical layer of the shale. The success of this method provides a promising way for reconstructing more realistic model to continuously and systematically characterize the pore (slits) structure from the nanopore-scale to the lREV-scale. It can advance the understanding of the various gas transport mechanisms at different scales and will be helpful for understanding the quality of the shale reservoir.

Jiang, Y., Chu, N., Zhang, W., Ma, J., Zhang, F., Liang, P., Zeng, R.J., 2019. Zinc: A promising material for electrocatalyst-assisted microbial electrosynthesis of carboxylic acids from carbon dioxide. Water Research 159, 87-94.


Abstract: Microbial electrosynthesis (MES) has been proposed as a sustainable platform to simultaneously achieve wastewater treatment, renewable energy generation and chemicals production. Currently, the CO2 valorization via MES is restricted by the low production rate, while that via electrochemical reduction is limited by the production of C1 products with high efficiency and selectivity. The electrocatalyst-assisted MES could potentially solve these bottlenecks of both MES and electrochemical reduction technology by increasing the production rate and expanding the product range. Here, four types of metals were evaluated for mixed culture-based, electrocatalyst-assisted MES with the fabrication of electrical-biological hybrid cathodes. Cathodes based on In, Zn, Ti and Cu showed high parallelism at 30 A/m2. However, no parallelism was observed at 50 A/m2, and only Zn experienced a further increase of the maximum acetic acid production rate (1.23 ± 0.02 g/L/d, 313 ± 5 g/m2/d) and titer (9.2 ± 0.1 g/L), with the highest value of the production rate normalized to the project area of the fiber cathodes. Other volatile fatty acids and ethanol were below 0.5 g/L. Moreover, it was the sharp H2 generation, which mainly caused the fluctuation of coulombic efficiency. The application of such Zn-based electrical-biological hybrid system shall provide a more efficient route for CO2 valorization.

Johnson, C.R., Fein, J.B., 2019. A mechanistic study of Au(III) removal from solution by Bacillus subtilis. Geomicrobiology Journal 36, 506-514.

https://doi.org/10.1080/01490451.2019.1573279

Bacteria–Au interactions control the fate of Au in a variety of geologic systems. Although previous studies have determined that non-metabolizing Bacillus subtilis cells can remove Au(III) from solution via cell surface adsorption reactions, and that upon removal Au(III) is rapidly reduced to Au(I) and remains bound to the cell surface, the mechanism of Au(III) removal by B. subtilis is poorly understood. This study provides further constraints on the mechanisms responsible for Au(III) removal by B. subtilis by conducting batch Au(III) removal experiments as a function of pH and Au loading (Au:biomass ratio) using biomass with and without two different types of treatment: (1) a treatment to remove extracellular polymeric substances (EPS) from the biomass, and (2) a treatment to irreversibly block surface sulfhydryl sites from Au binding. The experimental results suggest that Au(III) removal can be attributed primarily to Au complexation with bacterial sulfhydryl sites, but that Au–amino binding is also important under some conditions. Our experiments also suggest that

Au–sulfhydryl binding occurs predominantly on EPS molecules produced by B. subtilis, and that Au–amino binding is also important and is located within the bacterial cell envelope. These findings are the first to constrain the location of sulfhydryl-binding sites for B. subtilis biomass, and they are the first to demonstrate the important role played by bacterial EPS in the process of Au adsorption and reduction by bacteria.

Ju, Y., Beaubien, S.E., Lee, S.-S., Kaown, D., Hahm, D., Lee, S., Park, I.-W., Park, K., Yun, S.-T., Lee, K.-K., 2019. Application of natural and artificial tracers to constrain CO2 leakage and degassing in the K-COSEM site, South Korea. International Journal of Greenhouse Gas Control 86, 211-225.


Although Carbon Capture and Storage (CCS) has been demonstrated successfully on many occasions, the potential leakage of deep sequestrated CO2 into shallow groundwater remains a concern. To address this, an artificial injection experiment was performed at the K-COSEM test site in Eumseong, South Korea, that involved the release of CO2–infused water (16.9 kg of CO2 in 5 m3) containing He and Kr tracers into a shallow, heterogeneous, weathered-granite aquifer. The initial CO2–fluid was slightly oversaturated at the subsurface injection point, and thus the plume was expected to initially degas CO2 before equilibrating at in-situ conditions. Monitoring of carbonate system parameters in nearby observation wells helped define the evolution of the injected fluids, while the noble gas tracers were used to clearly define the physical behavior of the CO2 plume (including an estimate of degassed CO2 equal to 0.9–3.1%). This study demonstrates the potential use of noble gases for monitoring CO2 leakage in shallow aquifers, constraining mass balance and phase changes of leaking fluids, and better understanding local flow pathways. Furthermore, breakthrough of noble gases in this study was different from some previous experiments, suggesting that monitoring efficiency of these tracers may depend on leakage and site conditions.

Jung, J., Kang, H., Cao, S.C., Al-Raoush, R.I., Alshibli, K., Lee, J.Y., 2019. Effects of fine-grained particles’ migration and clogging in porous media on gas production from hydrate-bearing sediments. Geofluids 2019, Article 5061216.

https://doi.org/10.1155/2019/5061216

The migration of fine particles in porous media has been studied for different applications, including gas production from hydrate-bearing sediments. The clogging behavior of fine particles is affected by fine particle-pore throat size ratio, fine particle concentration, ionic concentration of fluids, and single/multiphase fluid flow. While previous studies presented valuable results, the data are not enough to cover a broad range of particle types and sizes and pore throat size in natural hydrate-bearing sediments. This paper presents a novel micromodel to investigate the effects of fine particle-pore throat size ratio, fine concentration, ionic concentration of fluid, and single/multiphase fluid flow on clogging or bridging in porous media. The results show that (1) the concentration of fine particles required to form clogging and/or bridging in pores decreased with the decrease in fine particle-pore throat size ratio, (2) the effects of ionic concentration of fluid on clogging behaviors depend on the types of fine particles, and (3) fine particles prefer to accumulate along the deionized water- (DW-) CO2 interface and migrate together, which in turn easily causes clogging in pores. As a result, multiphase fluid flow during gas production from hydrate-bearing sediments could easily develop clogging in pore throats, where the relative permeability of DW-CO2 in porous media decreases. Accordingly, the relatively permeability of porous media should be evaluated by considering the clogging behavior of fines.

Kamari, A., Mohammadi, A.H., Ramjugernath, D., 2019. Characterization of C7+ fraction properties of crude oils and gas-condensates using data driven models. Petroleum Science and Technology 37, 1516-1522.

https://doi.org/10.1080/10916466.2019.1570254

Petroleum fractions, in particular heptane-plus fraction (C7+), are complex mixtures and measuring properties of hydrocarbon-plus fractions is difficult and time-consuming. In this study, the normal boiling point, specific gravity and molecular weight of C7+ are estimated as a function of molecular weight, specific gravity as well as cumulative weight fractions using four soft computing strategies called least squares support vector machine, decision tree, gene expression programing, and artificial neural network. The results obtained in this study demonstrate that the developed models could be applied properly for the characterization and estimation of hydrocarbon–plus properties of crude oils and gas-condensates.

Kang, C.S., Dunfield, P.F., Semrau, J.D., 2019. The origin of aerobic methanotrophy within the Proteobacteria. FEMS Microbiology Letters 366, Article fnz096.


Aerobic methanotrophs play critical roles in the global carbon cycle, but despite their environmental ubiquity, they are phylogenetically restricted. Via bioinformatic analyses, it is shown that methanotrophy likely arose from methylotrophy from the lateral gene transfer of either of the two known forms of methane monooxygenase (particulate and soluble methane monooxygenases). Moreover, it appears that both known forms of pyrroloquinoline quinone-dependent methanol dehydrogenase (MeDH) found in methanotrophs—the calcium-containing Mxa-MeDH and the rare earth element-containing Xox-MeDH—were likely encoded in the genomes before the acquisition of the methane monooxygenases (MMOs), but that some methanotrophs subsequently received an additional copy of Xox-MeDH-encoding genes via lateral gene transfer. Further, data are presented that indicate the evolution of methanotrophy from methylotrophy not only required lateral transfer of genes encoding for methane monooxygenases, but also likely the pre-existence of a means of collecting copper. Given the emerging interest in valorizing methane via biological platforms, it is recommended that future strategies for heterologous expression of methane monooxygenase for conversion of methane to methanol also include cloning of genes encoding mechanism(s) of copper uptake, especially for expression of particulate methane monooxygenase.

Kang, M., He, L., Fan, D., Chen, J., Jia, G., 2019. Assessment of sedimentary heterocyst glycolipids as tracers of freshwater input to the Changjiang Estuary and East China Sea. Chemical Geology 521, 39-48.


Heterocyst glycolipids (HGs) are biomarkers of important freshwater and marine diazotrophs known as heterocystous cyanobacteria. Recent research has found that HGs with hexose moieties (C6) are derived from free-living, mostly freshwater species while those with pentose moieties (C5) are derived from diatom-symbiont, mostly marine species. Here, we analyzed 39 surface sediments from a study area ranging from the Changjiang Estuary to the offshore East China Sea for HGs to investigate distribution patterns at this freshwater-seawater interface. We detected both C5 and C6 HGs in these samples; however, they had different spatial distributions: the C6 HG abundance was highest at the freshwater end of the estuary and decease offshore, whereas the abundance of C5 HGs displayed

almost inverse pattern. We hypothesized that such distributions were likely caused by the mixing of freshwater and seawater, leading to a mixture of HGs derived from inland waters and/or soils and the marine environment. The proportion of C6 HGs to total HGs, defined as the FHG index, decreased with distance offshore, possibly reflecting the delivery of freshwater into the ocean. The FHG index changed curvilinearly with salinity, likely resulting from concentration-based weighting of end-member contributions. The FHG index correlated linearly (r2 = 0.76) with δ13Corg, suggesting that FHG could be used to indicate relative contributions of freshwater-delivered terrestrial organic matter in this estuarine and coastal region. However, the FHG index did not linearly correlate with the branched and isoprenoid tetraether (BIT) index, another proxy used for terrestrial input, likely because the BIT index is predominantly controlled by variations in marine crenarchaeol production.

Kashuba, N., Kırdök, E., Damlien, H., Manninen, M.A., Nordqvist, B., Persson, P., Götherström, A., 2019. Ancient DNA from mastics solidifies connection between material culture and genetics of mesolithic hunter–gatherers in Scandinavia. Communications Biology 2, Article 185.

https://doi.org/10.1038/s42003-019-0399-1

Human demography research in grounded on the information derived from ancient DNA and archaeology. For example, the study on the early postglacial dual-route colonisation of the Scandinavian Peninsula is largely based on associating genomic data with the early dispersal of lithic technology from the East European Plain. However, a clear connection between material culture and genetics has been lacking. Here, we demonstrate that direct connection by analysing human DNA from chewed birch bark pitch mastics. These samples were discovered at Huseby Klev in western Sweden, a Mesolithic site with eastern lithic technology. We generated genome-wide data for three individuals, and show their affinity to the Scandinavian hunter–gatherers. Our samples date to 9880-9540 calBP, expanding the temporal range and distribution of the early Scandinavian genetic group. We propose that DNA from ancient mastics can be used to study environment and ecology of prehistoric populations.

Kaushal, R., Ghosh, P., Pokharia, A.K., 2019. Stable isotopic composition of rice grain organic matter marking an abrupt shift of hydroclimatic condition during the cultural transformation of Harappan civilization. Quaternary International 512, 144-154.


Several hypotheses have been proposed to solve the conundrum of the cause of transition of Harappan civilization to a de-urbanized form in its Late Phase. In view of this, high-resolution off-site palaeoclimatic records along with archaeological findings provide strong evidence of an abrupt climate change ∼4000 yr BP (before present) that coincides with the civilization's cultural transition. The present study investigates whether this climatic shift recorded in palaeoclimate archives (speleothem, lake and marine sediments) at remote locations can be traced to the human settlements of Harappan civilization. This was accomplished by analyzing the remains of rice cereal-a highly water sensitive crop. The analysis involved measuring carbon and nitrogen isotopic compositions (δ13C, δ15N) of well-preserved rice grains recovered from archaeological sites belonging to the Harappan civilization and other contemporary regional cultures, representing the time windows between 4520 and 3400 yr BP. The parameter of intrinsic water use efficiency (WUEi) was used as an index for water availability in the rice crop's growth environment and was ascertained based on δ13C values measured in the bulk grain organic matter (OM). The observed WUEi values ranged between 49 and 69 μmol mol−1 and captured the variation in water availability. The δ15N values ranged from 5‰ to 6.5‰, thereby allowing us to confirm the role of climate in controlling δ13C variation in the

archaeological grains. The present findings will extend the usage of archaeobotanical cereal remains to deduce environmental changes at human settlements and will further our understanding of the process of Harappan cultural adaptation in response to decline in southwest monsoon at the Middle-Late Holocene boundary.



A thermophilic filamentous anoxygenic photosynthetic bacterium, Chloroflexus aggregans, is widely distributed in neutral to slightly alkaline hot springs. Sulfide has been suggested as an electron donor for autotrophic growth in microbial mats dominated with C. aggregans, but remarkable photoautotrophic growth of isolated C. aggregans has not been observed with sulfide as the sole electron source. From the idea that sulfide is oxidized to elemental sulfur by C. aggregans and the accumulation of elemental sulfur may have an inhibitory effect for the growth, the effects of an elemental sulfur-disproportionating bacterium was examined on the autotrophic growth of C. aggregans, strain NA9-6, isolated from Nakabusa hot spring. A sulfur-disproportionating bacterium, Caldimicrobium thiodismutans strain TF1, also isolated from Nakabusa hot spring was co-cultured with C. aggregans. C. aggregans and C. thiodismutans was successfully co-cultured in a medium containing thiosulfate as the sole electron source and bicarbonate as the sole carbon source. Quantitative conversion of thiosulfate to sulfate and a small transient accumulation of sulfide was observed in the co-culture. Then the electron source of the established co-culture was changed from thiosulfate to sulfide, and the growth of C. aggregans and C. thiodismutans was successfully observed with sulfide as the sole electron donor for the autotrophic growth of the co-culture. During the cultivation in the light, simultaneous consumption and accumulation of sulfide and sulfate, respectively, were observed, accompanied with the increase of cellular DNAs of both species. C. thiodismutans likely works as an elemental sulfur scavenger for C. aggregans, and C. aggregans seems to work as a sulfide scavenger for C. thiodismutans. These results suggest that C. aggregans grows autotrophically with sulfide as the electron donor in the co-culture with C. thiodismutans, and the consumption of elemental sulfur by C. thiodismutans enabled the continuous growth of the C. aggregans in the symbiotic system. This study shows a novel symbiotic relationship between a sulfide-oxidizing photoautotroph and an elemental sulfur-disproportionating chemolithoautotroph via cooperative dissimilatory sulfide oxidation to sulfate.



Ion mobility spectrometry–mass spectrometry (IMS-MS) combined with gas-phase hydrogen–deuterium exchange has been used to characterize novel psychoactive substances (NPSs) which are small synthetic compounds designed to mimic the effects of other illicit substances. Here, NPSs containing labile heteroatom hydrogens were evaluated for HDX reactivity in the presence of either deuterated water (D2O) or ammonia (ND3) within the drift tube. An initial evaluation of exchange propensity was performed for six NPSs. Five compounds exchanged in the presence of ND3 while only one NPS (benzyl piperazine) exchanged with D2O. The exchange mechanism of D2O requires

stabilization with a nearby charged site; the diamine ring of benzyl piperazine provided this charge site at a fixed length. Three disubstituted benzene isomers (o-, m-, and p-fluorophenyl piperazine) containing the diamine ring structure and a fluorine atom were subsequently analyzed. Having identical isotopic composition and nearly identical drift time distributions, these isomers could not be distinguished by IMS-MS alone. However, upon undergoing HDX in the drift tube, a t test of means (α = 0.05) showed that discrimination was possible if the exchange data from both reagent gases were included. Molecular dynamics simulations show that the proximity of the fluorine to the diamine ring hinders the dihedral angle rotation between the benzene and the diamine ring; this may partially account for the observed exchange differences.

Khan, S., Kay Lup, A.N., Qureshi, K.M., Abnisa, F., Wan Daud, W.M.A., Patah, M.F.A., 2019. A review on deoxygenation of triglycerides for jet fuel range hydrocarbons. Journal of Analytical and Applied Pyrolysis 140, 1-24.


Production of bio-jet fuel from triglycerides (TGs) based vegetable oils have recently received increased attention from research and industries because of its renewability and environmental benefits. Catalytic deoxygenation (DO) is a suitable way to produce bio-jet fuel from TGs. Presently, the main challenges faced by DO are the optimized selection of feedstocks, catalysts, reaction pathways and parameters. This review includes discussion on the feedstock and assessment of several potential catalysts: noble metals, sulphided, non-sulphided for DO of TGs. This assessment elucidates the model compounds of TGs, effect of operating parameters, potential catalysts and different DO reaction pathways to attain optimum yield and selectivity of desired products. In addition, some relevant discussion of TGs derived jet fuel specification, characteristics and fuel properties are also discussed. Overall, this review provides a comprehensive discussion on DO of TGs based vegetable oils in enhancing alternative jet fuel production in all relevant technical aspects.

Khelen, A.C., Manikyamba, C., Subramanyam, K.S.V., Santosh, M., Ganguly, S., Kalpana, M.S., Subba Rao, D.V., 2019. Archean seawater composition and depositional environment – Geochemical and isotopic signatures from the stromatolitic carbonates of Dharwar Craton, India. Precambrian Research 330, 35-57.


The well-preserved stromatolitic carbonates from Neoarchean Sandur, Chitradurga and Shimoga greenstone belts of Dharwar Craton were studied to constrain the depositional conditions, geochemical, isotopic characteristics and the Archean seawater temperatures. These rocks display limited diversity in their morphological features such as columnar (occasionally branched), pseudo-columnar, domal, crinkly laminated, and oval/elliptical shapes. The stromatolites are associated with Fe-Mn formations along with arenites, argillites, limestones and carbonaceous shales. These stromatolites are cherty dolomites having variable SiO2, MgO and CaO contents. The stromatolitic carbonates of the three greenstone belts possess low total Rare earth elements plus Ytterium (∑REY) along with positive La, Eu, Gd, Y anomalies and Y/Ho ratios reflecting their deposition in marine conditions with variable hydrothermal and terrigenous inputs. These stromatolites display predominantly negative δ13C values ranging from −1.61‰ to 0.01‰ VPDB of Sandur, −2.53‰ to 1.35‰ VPDB of Chitradurga and positive δ13C of Shimoga varying from −0.30‰ to 1.29‰ VPDB combined with the negative δ18O values (−20.95‰ to −7.72‰ VPDB). Our studies indicate fluctuating oxic to anoxic; acidic to alkaline environment responsible for the deposition of these stromatolites with locally varying Archean ocean temperatures from 25 to 75 °C. These conditions

favoured the deposition of cherty dolomitic stromatolites in a shallow marine environment ranging from supra to subtidal zones with the minor influence of hydrothermal activity which is evident for the existence of Archean smaller plate tectonics.

Kida, M., Tanabe, M., Tomotsune, M., Yoshitake, S., Kinjo, K., Ohtsuka, T., Fujitake, N., 2019. Changes in dissolved organic matter composition and dynamics in a subtropical mangrove river driven by rainfall. Estuarine, Coastal and Shelf Science 223, 6-17.


Dissolved organic matter (DOM) plays an important role in sustaining ecosystem services of mangrove forests through well-described biogeochemical and ecological functions. This study was conducted in the Fukido River (Ishigaki Island, Japan) to better understand the seasonal and episodic changes in DOM concentration and composition in a subtropical mangrove system. Water samples were collected seasonally along a headwater–mangrove–sea transect on 10 occasions from September 2014 through June 2016. DOM was fractionated based on hydrophobicity into two fractions (hydrophobic and hydrophilic) and also analyzed by excitation-emission matrix spectroscopy combined with parallel factor analysis (PARAFAC). Although seasonal changes in DOM concentration and composition were not observed, both hydrophobic and hydrophilic DOM concentrations and levels of the identified three PARAFAC components clearly increased during a typhoon event. It is suggested that episodic increases in freshwater input due to a typhoon caused enhanced leaching of DOM from mangrove litter and dissolution of mangrove soil organic matter (SOM), which was otherwise retained in the mangrove soil by salinity-induced aggregation. The aggregation–dissolution properties of SOM are crucial in determining the magnitude of DOM outwelling and possibly SOM accumulation rate by enhancing advective DOM exchanges. Future studies are needed to evaluate the size of the carbon pool and outwelling of DOM after classifying mangrove forests based on the hydrological regime that influences biogeochemical conditions in the forests. Regional Index Terms Japan, Okinawa, Ishigaki, Fukido.

Kim, E.J., Jung, W., Lim, S., Kim, S., Choi, H.-G., Han, S.J., 2019. Lipid production by arctic microalga Chlamydomonas sp. KNF0008 at low temperatures. Applied Biochemistry and Biotechnology 188, 326-337.

https://doi.org/10.1007/s12010-018-2921-1

A lipid-producing microalga, Chlamydomonas sp. KNF0008, collected from the Arctic was capable of growing at temperatures ranging from 4 to 20 °C, and the highest cell density was measured at 15 °C and 100 μmol photons m−2 s−1 light intensity under continuous shaking and external aeration. KNF0008 showed the elevated accumulation of lipid bodies under nitrogen-deficient conditions, rather than under nitrogen-sufficient conditions. Fatty acid production of KNF0008 was 4.2-fold (104 mg L−1) higher than that of C. reinhardtii CC-125 at 15 °C in Bold’s Basal Medium. The dominant fatty acids were C16:0, C16:4, C18:1, and C18:3, and unsaturated fatty acids (65.69%) were higher than saturated fatty acids (13.65%) at 15 °C. These results suggested that Arctic Chlamydomonas sp. KNF0008 could possibly be utilized for production of biodiesel during periods of cold weather because of its psychrophilic characteristics.

Kim, H.-J., Kim, J., 2019. A prebiotic synthesis of canonical pyrimidine and purine ribonucleotides. Astrobiology 19, 669-674.


The “RNA first” model for the origin of life holds that RNA emerged spontaneously on early Earth and developed into life through its dual capabilities for genetics and catalysis. The model's central weakness is the difficulty of making its building blocks, in particular, the glycosidic bond joining nucleobases to ribose. Thus, the focus of much of the modern literature on the topic is directed toward solving this difficulty and includes elegant, though indirect, methods for making this bond. Here, we report that the glycosidic bond in canonical pyrimidine and purine ribonucleotides can be formed by direct coupling of cyclic carbohydrate phosphates with free nucleobases, all reported to be available by experimentally supported pathways that might have operated on early Earth.

Kim, J., Dong, H., Yang, K., Park, H., Elliott, W.C., Spivack, A., Koo, T.-h., Kim, G., Morono, Y., Henkel, S., Inagaki, F., Zeng, Q., Hoshino, T., Heuer, V.B., 2019. Naturally occurring, microbially induced smectite-to-illite reaction. Geology 47, 535-539.

https://doi.org/10.1130/G46122.1

The occurrence of microbially induced smectite-to-illite (S-I) reaction has challenged both the notions of solely inorganic chemical control for this reaction and the conventional concept of a semiquantitative illite geothermometer for the reconstruction of the thermal and tectonic histories of sedimentary basins. Here, we present evidence for a naturally occurring microbially induced S-I transition, via biotic reduction of phyllosilicate structural Fe(III), in mudstones buried at the Nankai Trough, offshore Japan (International Ocean Discovery Program Site C0023). Biotic S-I reaction is a consequence of a bacterial survival and growth strategy at diagenetic temperatures up to 80 °C within the Nankai Trough mudstones. These results have considerable implications for petroleum exploration, modification of fault behavior, and the understanding of microbial communities in the deep biosphere.

Kim, Y.H., Leriche, G., Diraviyam, K., Koyanagi, T., Gao, K., Onofrei, D., Patterson, J., Guha, A., Gianneschi, N., Holland, G.P., Gilson, M.K., Mayer, M., Sept, D., Yang, J., 2019. Entropic effects enable life at extreme temperatures. Science Advances 5, Article eaaw4783.

http://advances.sciencemag.org/content/5/5/eaaw4783.abstract

Maintaining membrane integrity is a challenge at extreme temperatures. Biochemical synthesis of membrane-spanning lipids is one adaptation that organisms such as thermophilic archaea have evolved to meet this challenge and preserve vital cellular function at high temperatures. The molecular-level details of how these tethered lipids affect membrane dynamics and function, however, remain unclear. Using synthetic monolayer-forming lipids with transmembrane tethers, here, we reveal that lipid tethering makes membrane permeation an entropically controlled process that helps to limit membrane leakage at elevated temperatures relative to bilayer-forming lipid membranes. All-atom molecular dynamics simulations support a view that permeation through membranes made of tethered lipids reduces the torsional entropy of the lipids and leads to tighter lipid packing, providing a molecular interpretation for the increased transition-state entropy of leakage.

Kirkpatrick, J.B., Walsh, E.A., D’Hondt, S., 2019. Microbial selection and survival in subseafloor sediment. Frontiers in Microbiology 10, 956. doi: 10.3389/fmicb.2019.00956.


Many studies have examined relationships of microorganisms to geochemical zones in subseafloor sediment. However, responses to selective pressure and patterns of community succession with sediment depth have rarely been examined. Here we use 16S rDNA sequencing to examine the succession of microbial communities at sites in the Indian Ocean and the Bering Sea. The sediment ranges in depth from 0.16 to 332 meters below seafloor and in age from 660 to 1,300,000 years. The majority of subseafloor taxonomic diversity is present in the shallowest depth sampled. The best predictor of sequence presence or absence in the oldest sediment is relative abundance in the near-seafloor sediment. This relationship suggests that perseverance of specific taxa into deep, old sediment is primarily controlled by the taxonomic abundance that existed when the sediment was near the seafloor. The OTUs that dominate at depth comprise a subset of the local seafloor community at each site, rather than a grown-in group of geographically widespread subseafloor specialists. At both sites, most taxa classified as abundant decrease in relative frequency with increasing sediment depth and age. Comparison of community composition to cell counts at the Bering Sea site indicates that the rise of the few dominant taxa in the deep subseafloor community does not require cell replication, but might simply result from lower mortality relative to competing taxa on the long timescale of community burial.



Phenol is an important chemical product that can be used in a wide variety of applications, and it is currently produced from fossil resources. Fermentation production of phenol from renewable biomass resources by microorganisms is highly desirable for sustainable development. However, phenol toxicity hampers phenol production in industrial microorganisms such as Escherichia coli. In the present study, it was revealed that culturing E. coli in the presence of phenol not only decreased growth rate, but also biomass yield. This suggests that phenol affects the carbon flow of the metabolism, but the mechanism is unknown. To investigate the effect of phenol on the flux distribution of central carbon metabolism, 13C-metabolic flux analysis (13C-MFA) was performed on cells grown under different phenol concentrations (0, 0.1, and 0.15%). 13C-MFA revealed that the TCA cycle flux reduced by 25% increased acetate production from acetyl-CoA by 30% in the presence of 0.1% phenol. This trend of flux changes was emphasized at a phenol concentration of 0.15%. Although the expression level of citrate synthase, which catalyzes the first reaction of the TCA cycle, does not change regardless of phenol concentrations, the in vitro enzyme activity assay shows that the reaction was inhibited by phenol. These results suggest that the TCA cycle flux decreased due to phenol inhibition of citrate synthase; therefore, ATP could not be sufficiently produced by respiration, and growth rate decreased. Furthermore, since carbon was lost as acetate due to overflow metabolism, the biomass yield became low in the presence of phenol.

Knapp, L.J., Harris, N.B., McMillan, J.M., 2019. A sequence stratigraphic model for the organic-rich Upper Devonian Duvernay Formation, Alberta, Canada. Sedimentary Geology 387, 152-181.


The Upper Devonian Duvernay Formation of western Canada is a prolific source rock that in recent years has become an important exploration target for shale gas and oil. We present a sequence stratigraphic model for the Duvernay Formation that characterizes relationships between sea level, basin circulation, lithofacies distribution, and mechanisms for sediment transport and organic-

enrichment. The study demonstrates lateral and stratigraphic variability in the character of sequence stratigraphic surfaces and systems tracts and interprets this variability in the context of sea level cycles at varying time scales. Correlation of 24 core descriptions to a network of 759 wells with wireline logs led to the creation of a basin-scale sequence stratigraphic framework.

Three 3rd order depositional sequences are identified; the middle sequence straddles a 2nd order maximum flooding surface. Each systems tract shows unique trends in lithofacies, rock properties, and wireline character. Transgressive systems tracts are characterized by the increasingly widespread deposition of clay-poor, siliceous, organic-rich mudstones in the basin, resulting from decreased clastic and carbonate input, concentration of pelagic organic matter and siliceous radiolaria, and low oxygen concentrations in basin center bottom waters. Highstand systems tracts are characterized by sustained radiolarian input and increases in carbonate sediment due to shedding of carbonate detritus during aggradation and progradation of platform margins and reefs. Lowstand systems tracts are more clastic-rich and organic-poor. Near reef complexes, coarse carbonates locally mark the base of the lowstand systems tract. Bottom currents reworked mud- and silt-sized material in toe-of-slope locations and contributed to slope-parallel progradation during regression.

Knutz, P.C., Newton, A.M.W., Hopper, J.R., Huuse, M., Gregersen, U., Sheldon, E., Dybkjær, K., 2019. Eleven phases of Greenland Ice Sheet shelf-edge advance over the past 2.7 million years. Nature Geoscience 12, 361-368.

https://doi.org/10.1038/s41561-019-0340-8

The reconstruction of former ice sheets is important for testing Earth system models that can assess interactions between polar ice sheets and global climate, but information retrieved from contemporary glaciated margins is sparse. In particular, we need to know when ice sheets began to form marine outlets and the mechanisms by which they advance and retreat over timescales from decades to millions of years. Here, we use a dense grid of high-quality two-dimensional seismic reflection data to examine the stratigraphy and evolution of glacial outlets, or palaeo-ice streams, that drained the northwest Greenland Ice Sheet into Baffin Bay. Seismic horizons are partly age constrained by correlation with cores from drill sites. Progradational units separated by onlap surfaces record 11 major phases of shelf-edge ice advance and subsequent transgression since the first ice-sheet expansion 3.3–2.6 million years ago. The glacial outlet system appears to have developed in four stages, each potentially caused by tectonic and climatic changes. We infer that an abrupt change in ice-flow conditions occurred during the mid-Pleistocene transition, about 1 million years ago, when ice movement across the shelf margin changed from widespread to a more focused flow (ice streams), forming the present-day glacial troughs.

Koelschbach, J.S., Mouttaki, H., Merl-Pham, J., Arnold, M.E., Meckenstock, R.U., 2019. Identification of naphthalene carboxylase subunits of the sulfate-reducing culture N47. Biodegradation 30, 147-160.

https://doi.org/10.1007/s10532-019-09872-z

Expanding industrialization and the associated usage and production of mineral oil products has caused a worldwide spread of polycyclic aromatic hydrocarbons. These pollutants accumulate and persist under anoxic conditions but little is known about the biochemical reactions catalyzing their anaerobic degradation. Recently, carboxylation of naphthalene was demonstrated for the sulfate-reducing culture N47. Proteogenomic studies on N47 allowed the identification of a gene cluster with products suggested to be involved in the initial reaction of naphthalene degradation. Here, we performed comparative proteomic studies with N47 proteins extracted from naphthalene versus 2-

methylnapththalene-grown cells on blue native PAGE. The analysis led to the identification of subunits of the naphthalene carboxylase of N47. Moreover, we show that the identified subunits are encoded in an operon structure within the previously mentioned naphthalene carboxylase gene cluster. These findings were supported by a pull-down experiment revealing in vitro interaction partners of a heterologously produced GST-tagged naphthalene carboxylase subunit. Based on these lines of evidence, naphthalene carboxylase is proposed to be a complex of about 750 kDa. Naphthalene carboxylase can be seen as a prototype of a new enzyme family of UbiD like de-/carboxylases catalyzing the anaerobic activation of non-substituted polycyclic aromatic hydrocarbons.

Kouketsu, Y., Tsai, C.-H., Enami, M., 2019. Discovery of unusual metamorphic temperatures in the Yuli belt, eastern Taiwan: New interpretation of data by Raman carbonaceous material geothermometry. Geology 47, 522-526.

https://doi.org/10.1130/G45934.1

The crystallinity of carbonaceous material (CM) in metasedimentary schists in the Yuli belt, eastern Taiwan, shows unusual diversity. The difference between the maximum and minimum temperatures estimated by a Raman CM geothermometer reaches 200 °C, which is much wider than those in other metamorphic belts and contact aureoles. In light of these results, we considered two possible explanations: (1) a mixture of detrital and metamorphic graphite grains, and (2) a mixture of different reactive CM during short-lived metamorphism. One sample shows a near-bimodal peak, suggesting the former hypothesis, while the other two samples show a continuous single peak, suggesting the latter possibility. Detailed analyses of CM crystallinities have the potential to extract information relating not only to the peak metamorphic temperature, but also to the pre-metamorphic history or the duration of heating in a metamorphic belt.

Krueckert, K.K., Seibold, P., 2019. Enhanced evaluation of asphaltene-related oil properties to facilitate production in a complex offshore environment. Energy & Fuels 33, 3711-3722.


Asphaltene destabilization is a widespread problem in the oil industry. Under initial pressure and temperature conditions in the oil reservoir, asphaltenes are stabilized by building micelle structures in which they are associated with resin and aromatic compounds. Stable asphaltenes do not pose problems during oil production; however, if pressure/temperature conditions change throughout the production system, asphaltenes might become destabilized. Once destabilized, asphaltenes can potentially impair the whole production system. The development and implementation of a profound chemical injection strategy to mitigate asphaltene-related problems are paramount for a successful and sustainable fluid production if routine operating conditions are within the asphaltene instability range. A preventive asphaltene mitigation strategy is generally preferred; i.e., it is beneficial to avoid the occurrence of asphaltene-related problems in the first instance, instead of applying any remediation method afterward. Boundary conditions defined by the oil characteristics and the actual production conditions can make the development of a completely preventive chemical treatment strategy challenging. This applies especially in the offshore sector of the industry with given limitations in accessibility to the production and storage facilities accompanied by stringent regulatory requirements. This paper describes the analysis of a crude oil produced in a complex offshore environment, including mixing with condensate and storage in a gravity-based subsea tank. It highlights the asphaltene-related characteristics and compares different technologies to assess stability of the oil in neat form and upon mixing with condensate. The impact of different asphaltene

inhibitors/dispersants on the oil has been investigated, and additionally, the effectiveness of dissolver chemicals on artificially sedimented asphaltene deposits has been evaluated. Different lab experiments have been conducted to determine the asphaltene concentration in the fluid and sediment layer over time with the aim to quantify the sedimentation. Computational fluid dynamics (CFD) was used to simulate potential sedimentation phenomena. This paper is based on a presentation given at the 19th International Conference on Petroleum Phase Behavior and Fouling (Petrophase 2018) in Park City, UT, U.S.A. Names of the platforms, distinct locations, and actual production numbers are not revealed in the paper with respect to information protection requirements of the parties involved.

Kuhry, P., Bárta, J., Blok, D., Elberling, B., Faucherre, S., Hugelius, G., Richter, A., Šantrůčková, H., Weiss, N., 2019. Lability classification of soil organic matter in the northern permafrost region. Biogeosciences Discussions 2019, 1-30.

https://www.biogeosciences-discuss.net/bg-2019-89/

The large stocks of soil organic carbon (SOC) in soils and deposits of the northern permafrost region are sensitive to global warming and permafrost thawing. The potential release of this carbon (C) as greenhouse gases to the atmosphere does not only depend on the total quantity of soil organic matter (SOM) affected by warming and thawing, but also on its lability (i.e. the rate at which it will decay). In this study we develop a simple and robust classification scheme of SOM lability for the main types of soils and deposits of the northern permafrost region. The classification is based on widely available soil geochemical parameters and landscape unit classes, which makes it useful for upscaling to the entire northern permafrost region. We have analyzed the relationship between C content and C-CO2 production rates of soil samples in two different types of laboratory incubation experiment. In one experiment, c. 240 soil samples from four study areas were incubated using the same protocol (at 5 °C, aerobically) over a period of one year. Here we present C release rates measured on day 343 of incubation. These long-term results are compared to those obtained from short-term incubations of c. 1000 samples (at 12 °C, aerobically) from an additional three study areas. In these experiments, C-CO2 production rates were measured over the first four days of incubation. We have focused our analyses on the relationship between C-CO2 production per gram dry weight per day (µgC-CO2 gdw−1 d−1) and C content (%C of dry weight) in the samples, but show that relationships are consistent when using C / N ratios or different production units such as µgC per gram soil C per day (µgC-CO2 gC−1 d−1) or per cm of soil per day (µgC-CO2 cm3−1 d−1). C content of the samples is positively correlated to C-CO2 production rates but explains less than 50 % of the observed variability when the full datasets are considered. A partitioning of the data into landscape units greatly reduces variance and provides consistent results between incubation experiments. These results indicate that relative SOM lability decreases in the order: Late Holocene eolian deposits > alluvial deposits and mineral upland soils (including peaty wetlands) > Pleistocene Yedoma deposits > C-enriched pockets in cryoturbated soils > peat deposits. Thus, three of the most important SOC storage classes in the northern permafrost region (Yedoma, cryoturbated soils and peatlands) show low relative SOM lability. Previous research has suggested that SOM in these pools is relatively undecomposed and the reasons for the observed resistance to decomposition in our experiments needs urgent attention if we want to better constrain the magnitude of the thawing permafrost carbon feedback on global warming.

Kunene, T., Xiong, L., Rosenthal, J., 2019. Solar-powered synthesis of hydrocarbons from carbon dioxide and water. Proceedings of the National Academy of Sciences 116, 9693-9695.


The synthesis of hydrocarbons via electroreduction of CO2 is an attractive approach to store energy generated from intermittent renewable sources of electricity (e.g., solar) through formation of the high-energy C–C and C–H bonds of reduced carbon compounds (1, 2). Establishment of such processes also represents a critical step toward the sustainable production of carbon-based commodity chemicals and energy-rich liquid fuels from nonpetroleum resources (3). Despite the promise that such strategies hold, facilitating the rapid, selective, and efficient electrosynthesis of multicarbon products from CO2 is an inherently difficult proposition. Part of the challenge stems from the fact that CO2 reduction half-reactions that generate value-added C1 and multicarbon products take place within a narrow potential window that is less than 0.5 V wide (Fig. 1).Fig. 1. Equilibrium potentials for reductive and oxidative half-reactions relevant to the synthesis of hydrocarbons from carbon dioxide, water, and sunlight. Electron and proton equivalents generated via water oxidation at the anode of an EC can be utilized for fuel-forming cathodic processes to generate hydrogen gas or a broad array of reduced carbon products. Promoting the efficient and selective formation of hydrocarbons of high value and utility requires a highly integrated approach in which electrocatalysts, electrolytes, cell parameters, and light-harvesting assemblies are optimized to work together.As a result of the reaction landscape illustrated in Fig. 1, it is virtually impossible to target a given CO2 reduction product based purely on thermodynamic considerations. For instance, electrochemical reduction of CO2 to ethylene occurs at 0.08 V vs. reversible hydrogen electrode (RHE). Accordingly, any electrochemical process that targets this product must be run at a potential at which production of other species such as ethane (E° = 0.14 V) and methane (E° = 0.17 V) is also thermodynamically feasible. Moreover, kinetics associated …

Kwon, H., Kim, M.G., Lee, Y.I., 2019. Mercury evidence from the Sino-Korean block for Emeishan volcanism during the Capitanian mass extinction. Geological Magazine 156, 1105-1110.

https://doi.org/10.1017/S0016756818000481

A prominent large negative δ13Corg excursion and a coeval notable spike in mercury (Hg)/total organic carbon ratio are observed in the middle–upper Permian Gohan Formation in central Korea, located in the eastern Sino-Korean block (SKB), which may represent the Capitanian mass extinction event. The SKB was separated from the South China block by the eastern Palaeo-Tethys Ocean. This finding from the SKB supports the widespread Hg loading to the environment emitted from the Emeishan volcanic eruptions in SW China. This study demonstrates that the Hg cycle was globally perturbed in association with global carbon cycle perturbation that occurred during the Capitanian Extinction.

Kwon, M.J., Jung, J.Y., Tripathi, B.M., Göckede, M., Lee, Y.K., Kim, M., 2019. Dynamics of microbial communities and CO2 and CH4 fluxes in the tundra ecosystems of the changing Arctic. Journal of Microbiology 57, 325-336.

https://doi.org/10.1007/s12275-019-8661-2

Arctic tundra ecosystems are rapidly changing due to the amplified effects of global warming within the northern high latitudes. Warming has the potential to increase the thawing of the permafrost and to change the landscape and its geochemical characteristics, as well as terrestrial biota. It is important to investigate microbial processes and community structures, since soil microorganisms play a significant role in decomposing soil organic carbon in the Arctic tundra. In addition, the feedback from tundra ecosystems to climate change, including the emission of greenhouse gases into the atmosphere, is substantially dependent on the compositional and functional changes in the soil microbiome. This article reviews the current state of knowledge of the soil microbiome and the two most abundant greenhouse gas (CO2 and CH4) emissions, and summarizes permafrost thaw-induced

changes in the Arctic tundra. Furthermore, we discuss future directions in microbial ecological research coupled with its link to CO2 and CH4 emissions.


https://doi.org/10.1080/08120099.2019.1577298

Microscopic pore structure and water distribution are important and fundamental parameters for coalbed methane reservoir characterisation. These are closely related to the calculation/interpretation of other critical parameters, such as permeability and flow capacity. In this study, scanning electron microscopy, low-pressure nitrogen gas adsorption, nuclear magnetic resonance spectroscopy, and theoretical calculations were used to study the pore structure characteristics and water distribution of Zhaozhuang coal mine in the southeastern Qinshui Basin, PR China. The results show that the pore radius ranges from 2.066 to 594.045 nm, mainly classified as micropores and transitional pores. The micropores significantly contribute to the total pore volume. The adsorption pores (micropores and transitional pores) contribute the most to the total specific surface area. The T2 spectrum distributions of saturated water samples show two peaks. The first T2 spectrum peak is related to adsorption pores, whereas the second T2 spectrum peak is related to seepage pores. The seepage pores were not well developed as the adsorption pores. Most adsorption pores are saturated with irreducible water that could not be discharged by centrifugation, whereas the seepage pores are saturated with movable water that could be completely discharged by centrifugation. The T2 cutoff method was used to calculate the irreducible water saturation, and the irreducible water saturation of the sample was ≥90%. The irreducible water was mainly distributed in the micropores, and some of the irreducible water was distributed in the transitional pores. The irreducible water that remains in the pores can cause reservoir damage.



The pumice volcanic samples could have possible connections to the evolution of life and give us insight about their bio-geochemical processes related. In this regard, the samples from the volcanic eruption from La Restinga (El Hierro, Spain) in 2011 have been mainly studied by means of Raman spectroscopy. The research also includes analysis of XRD, Scanning Electron Microscopy and Optical Microscopy to support the Raman analysis. The results show that the Raman methods and mineral analyses are in strong agreement with the results obtained from other authors and techniques. The internal white foamy core (WFC) of the studied pumice samples shows amorphous silica, Fe-oxides, Ti-oxides, quartz, certain sulfates, carbonates, zeolites and organics. On the other hand, the external part (dark crust – DC) of these samples mainly presents primary-sequence mineralogy combined with some secondary alteration minerals such as olivine, feldspar, pyroxene, amorphous silica, and Fe-oxide. Raman spectroscopy detected other minerals not yet reported on these samples like barite, celestine and lepidocrocite. Also, the different chemometric and calibration methods for Raman spectroscopy in elemental composition, mineral classification and structural characterization has been successfully applied.

From the astrobiological perspective, the research was also complemented with comparisons to other similar samples from terrestrial analogs. The main consideration was taking into account the proposed hypothesis regarding the potential behavior of the pumice as a substrate for the evolution of life. Furthermore, the detailed analysis from La Restinga eruption is coherent with the mineral phases and processes discussed from previous literature. The white internal part fulfills the conditions to work as an organic reservoir, confirmed by the detection of organic matter and selected minerals that could be used as energy sources for bacterial communities. The external layers of the samples work as a shielding layer to protect the organics from decay in extreme conditions. Finally, here we have demonstrated that the characteristics and advantages of Raman spectroscopy could help to assess and understand the possible biogenicity and alteration processes of any geological sample to be found on Mars.

Lam, S.C., Sanz Rodriguez, E., Haddad, P.R., Paull, B., 2019. Recent advances in open tubular capillary liquid chromatography. Analyst 144, 3464-3482.

http://dx.doi.org/10.1039/C9AN00329K

This review covers advances and applications of open tubular capillary liquid chromatography (OT-LC) over the period 2007–2018. Under the right conditions OT-LC columns have the potential to offer superior column efficiency, higher overall peak capacity, and higher column permeability compared to packed capillary and monolithic columns. However, such advantages are highly dependent upon column format and dimensions, and to date in liquid chromatography the advantages of open tubular format columns have been most widely discussed and applied in the field of proteomics. In this review we have focused on the wider variety of separation mechanisms and applications which can be achieved following the modification of the inner wall of the capillary with a thin-layer stationary phase. In particular the latest advances in stationary phase development and formation, together with new column formats and dimensions are reviewed. Detection options for OT-LC are also discussed and recent advances in this area highlighted. Finally, this review summarises existing applications of OT-LC and illustrates the future potential for this technique.

Lan, X., Tans, P., Sweeney, C., Andrews, A., Dlugokencky, E., Schwietzke, S., Kofler, J., McKain, K., Thoning, K., Crotwell, M., Montzka, S., Miller, B.R., Biraud, S.C., 2019. Long-term measurements show little evidence for large increases in total U.S. methane emissions over the past decade. Geophysical Research Letters 46, 4991-4999.

https://doi.org/10.1029/2018GL081731

Abstract: Recent studies show conflicting estimates of trends in methane (CH4) emissions from oil and natural gas (ONG) operations in the United States. We analyze atmospheric CH4 measurements from 20 North American sites in the National Oceanic and Atmospheric Administration Global Greenhouse Gas Reference Network and determined trends for 2006–2015. Using CH4 vertical gradients as an indicator of regional surface emissions, we find no significant increase in emissions at most sites and modest increases at three sites heavily influenced by ONG activities. Our estimated increases in North American ONG CH4 emissions (on average approximately 3.4 ± 1.4 %/year for 2006–2015, ±σ) are much smaller than estimates from some previous studies and below our detection threshold for total emissions increases at the east coast sites that are sensitive to U.S. outflows. We also find an increasing trend in ethane/methane emission ratios, which has resulted in major overestimation of oil and gas emissions trends in some previous studies.

Plain Language Summary: In the past decade, natural gas production in the United States has increased by ~46%. Methane emissions associated with oil and natural gas productions have raised concerns since methane is a potent greenhouse gas with the second largest influence on global warming. Recent studies show conflicting results regarding whether methane emissions from oil and gas operations have been increased in the United States. Based on long‐term and well‐calibrated measurements, we find that (i) there is no large increase of total methane emissions in the United States in the past decade; (ii) there is a modest increase in oil and gas methane emissions, but this increase is much lower than some previous studies suggest; and (iii) the assumption of a time‐constant relationship between methane and ethane emissions has resulted in major overestimation of an oil and gas emissions trend in some previous studies.

Langenheder, S., Lindström, E.S., 2019. Factors influencing aquatic and terrestrial bacterial community assembly. Environmental Microbiology Reports 11, 306-315.

https://doi.org/10.1111/1758-2229.12731

During recent years, many studies have shown that different processes including drift, environmental selection and dispersal can be important for the assembly of bacterial communities in aquatic and terrestrial ecosystems. However, we lack a conceptual overview about the ecological context and factors that influence the relative importance of the different assembly mechanisms and determine their dynamics in time and space. Focusing on free‐living, i.e., nonhost associated, bacterial communities, this minireview, therefore, summarizes and conceptualizes findings from empirical studies about how (i) environmental factors, such as environmental heterogeneity, disturbances, productivity and trophic interactions; (ii) connectivity and dispersal rates (iii) spatial scale, (iv) community properties and traits and (v) the use of taxonomic/phylogenetic or functional metrics influence the relative importance of different community assembly processes. We find that there is to‐date little consistency among studies and suggest that future studies should now address how (i)–(v) differ between habitats and organisms and how this, in turn, influences the temporal and spatial‐scale dependency of community assembly processes in microorganisms.

Lantink, M.L., Davies, J.H.F.L., Mason, P.R.D., Schaltegger, U., Hilgen, F.J., 2019. Climate control on banded iron formations linked to orbital eccentricity. Nature Geoscience 12, 369-374.

https://doi.org/10.1038/s41561-019-0332-8

Astronomical forcing associated with Earth’s orbital and inclination parameters (Milankovitch forcing) exerts a major control on climate as recorded in the sedimentary rock record, but its influence in deep time is largely unknown. Banded iron formations, iron-rich marine sediments older than 1.8 billion years, offer unique insight into the early Earth’s environment. Their origin and distinctive layering have been explained by various mechanisms, including hydrothermal plume activity, the redox evolution of the oceans, microbial and diagenetic processes, sea-level fluctuations, and seasonal or tidal forcing. However, their potential link to past climate oscillations remains unexplored. Here we use cyclostratigraphic analysis combined with high-precision uranium–lead dating to investigate the potential influence of Milankovitch forcing on their deposition. Field exposures of the 2.48-billion-year-old Kuruman Banded Iron Formation reveal a well-defined hierarchical cycle pattern in the weathering profile that is laterally continuous over at least 250 km. The isotopic ages constrain the sedimentation rate at 10 m Myr−1 and link the observed cycles to known eccentricity oscillations with periods of 405 thousand and about 1.4 to 1.6 million years. We conclude that long-period, Milankovitch-forced climate cycles exerted a primary control on large-scale compositional variations in banded iron formations.

Larson, E.A., Lee, J., Paulson, A., Lee, Y.J., 2019. Structural analysis of polyurethane monomers by pyrolysis GC TOFMS via dopant-assisted atmospheric pressure chemical ionization. Journal of The American Society for Mass Spectrometry 30, 1046-1058.

https://doi.org/10.1007/s13361-019-02165-y

Polyurethane is one of the most widely used copolymers and is formed by the cross-linking of isocyanates and polyols. Its physical properties have a strong dependence on the monomer structures, making it very important to characterize the monomers in polyurethane. In this study, we developed a method to analyze unknown polyurethane samples using pyrolysis gas chromatography time-of-flight mass spectrometry (Py-GC-TOFMS) with dopant-assisted atmospheric pressure chemical ionization (dAPCI). A set of standard polyurethane foams produced with several different monomers are analyzed by Py-GC-TOFMS. GC-dAPCI-TOFMS is a high-resolution, soft ionization method for GC-MS analysis that provides accurate mass information of GC separated molecules. The data obtained by this approach could effectively classify different monomers using principal component analysis (PCA), grouping polymers with the same monomers, and providing structural features significant to each monomer. Furthermore, characteristic compounds are identified using in-source collision-induced dissociation (CID) and CSI:FingerID analysis. In contrast, the same set of samples analyzed by Py-GC-electron ionization (EI)-MS could only partially separate some of the monomers.

Laruelle, G.G., Marescaux, A., Le Gendre, R., Garnier, J., Rabouille, C., Thieu, V., 2019. Carbon dynamics along the Seine River network: Insight from a coupled estuarine/river modeling approach. Frontiers in Marine Science 6, 216. doi: 10.3389/fmars.2019.00216.


The Seine River discharges over 700 Gg of carbon (C) every year into the sea mostly under the form of Dissolved Inorganic Carbon (DIC) and emits 445 Gg under the form of carbon dioxide (CO2) to the atmosphere over its entire river network. The watershed, which drains 76,000 km2, is heavily populated with 18 106 inhabitants and is thus submitted to large anthropic pressure. The offline coupling of two Reactive Transport Models is used to understand the complex spatial and temporal dynamics of carbon, oxygen and nutrients and quantify the CO2 exchange at the air-water interface along the main axis of the river. The estuarine section of the Seine is simulated by the generic estuarine model C-GEM (for Carbon Generic Estuarine Model), while the upstream part of the network, devoid of tidal influence is simulated by the pyNuts-Riverstrahler modeling platform which also includes an explicit representation of the drainage network ecological functioning. Our simulations provide a process-based representation of nutrients, oxygen, total organic carbon (TOC) and the carbonate system (DIC and alkalinity) over the entire year 2010. Our coupled modelling chain allows quantifying the respective contributions of the estuarine and freshwater sections of the system in the removal of carbon as well as following the fate of TOC and DIC along the river network. Our results also allow calculating an integrated carbon budget of the Seine river network for year 2010.

Lavrieux, M., Birkholz, A., Meusburger, K., Wiesenberg, G.L.B., Gilli, A., Stamm, C., Alewell, C., 2019. Plants or bacteria? 130 years of mixed imprints in Lake Baldegg sediments (Switzerland), as revealed by compound-specific isotope analysis (CSIA) and biomarker analysis. Biogeosciences 16, 2131-2146.

https://www.biogeosciences.net/16/2131/2019/

Soil erosion and associated sediment transfer are among the major causes of aquatic ecosystem and surface water quality impairment. Through land use and agricultural practices, human activities modify the soil erosive risk and the catchment connectivity, becoming a key factor of sediment dynamics. Hence, restoration and management plans of water bodies can only be efficient if the sediment sources and the proportion attributable to different land uses are identified. According to this aim, we applied two approaches, namely compound-specific isotope analysis (CSIA) of long-chain fatty acids (FAs) and triterpenoid biomarker analysis, to a eutrophic lake, Lake Baldegg, and its agriculturally used catchment (Switzerland). Soils reflecting the five main land uses of the catchment (arable lands, temporary and permanent grasslands, mixed forests, orchards) were subjected to CSIA. The compound-specific stable isotope δ13C signatures clearly discriminate between potential grasslands (permanent and temporary) and forest sources. Signatures of agricultural land and orchards fall in between. The soil signal was compared to the isotopic signature of a lake sediment sequence covering ca. 130 years (before 1885 to 2009). The recent lake samples (1940 to 2009, with the exception of 1964 to 1972) fall into the soil isotopic signature polygon and indicate an important contribution of the forests, which might be explained by (1) the location of the forests on steep slopes, resulting in a higher connectivity of the forests to the lake, and/or (2) potential direct inputs of trees and shrubs growing along the rivers feeding the lake and around the lake. However, the lake sediment samples older than 1940 lie outside the source soils' polygon, as a result of FA contribution from a not yet identified source, most likely produced by an in situ aquatic source, either algae, bacteria or other microorganisms or an ex-site historic source from wetland soils and plants (e.g. Sphagnum species). Despite the overprint of the yet unknown source on the historic isotopic signal of the lake sediments, land use and catchment history are clearly reflected in the CSIA results, with isotopic shifts being synchronous with changes in the catchment, land use and eutrophication history. The investigated highly specific biomarkers were not detected in the lake sediment, even though they were present in the soils. However, two trimethyltetrahydrochrysenes (TTHCs), natural diagenetic products of pentacyclic triterpenoids, were found in the lake sediments. Their origin is attributed to the in situ microbial degradation of some of the triterpenoids. While the need to apportion sediment sources is especially crucial in eutrophic systems, our study stresses the importance of exercising caution with CSIA and triterpenoid biomarkers in such environments, where the active metabolism of bacteria might mask the original terrestrial isotopic signals.

Lazar, C.S., Lehmann, R., Stoll, W., Rosenberger, J., Totsche, K.U., Küsel, K., 2019. The endolithic bacterial diversity of shallow bedrock ecosystems. Science of The Total Environment 679, 35-44.


Terrestrial subsurface microbial communities are not restricted to the fluid-filled void system commonly targeted during groundwater sampling but are able to inhabit and dwell in rocks. However, compared to the exploration of the deep biosphere, endolithic niches in shallow sedimentary bedrock have received little interest so far. Despite the potential contribution of rock matrix dwellers to matter cycling and groundwater resource quality, their identity and diversity patterns are largely unknown. Here, we investigated the bacterial diversity in twenty-two rock cores in common limestone-mudstone alternations that differed in rock permeabilities and other geostructural and petrological factors. 16S rRNA gene analysis showed the existence of a unique rock matrix microbiome compared to surrounding groundwater. Typically, shallow weathered limestones contained bacterial groups most likely originating from soil habitats. In low-permeable mudstones, we found similar communities of oligotrophic heterotrophs, and thiosulfate-oxidizing autotrophs, without relation to depth, rock type and bulk rock permeability. In fractured limestone, the bacterial communities of fracture surfaces were distinct from their matrix counterparts and ranged from organic matter decomposers in outcrop areas to autotrophs in downdip positions that receive limited surface input.

Contrastingly, rock matrices from lithologically corresponding, but highly isolated environments, were dominated by spore-forming bacteria, oligotrophic heterotrophs and hydrogen-oxidizing autotrophs. Neither depth, matrix permeability nor major mineralogy dominantly controlled the endolithic bacterial diversity. Instead, a combination of subsurface factors drives the supply of niches by fluids, matter and energy as well as the (re)dispersal conditions that likely shape bacterial diversity.

Le Gresley, A., Broadberry, G., Robertson, C., Peron, J.-M.R., Robinson, J., O’Leary, S., 2019. Application of pure shift and diffusion NMR for the characterisation of crude and processed pyrolysis oil. Journal of Analytical and Applied Pyrolysis 140, 281-289.


By combining diffusion-ordered NMR spectroscopy (DOSY) and pure shift NMR spectroscopy ((Pure Shift Yielded By Chirp Excitation (PSYCHE)) with 1D NMR metabolite assignment, we demonstrate an improved method for in situ analysis of pre and post-processed pyrolysis oil to quickly establish the most effective upgrading procedure. These experiments use molecular mass estimations from DOSY and single component verification using PSYCHE to confirm the identity of metabolites and show how the mass pattern for pyrolysis oils varies depending on how it is upgraded.

With the use of a semi-automatic approach for metabolite assignment, we have verified and quantified individual components, giving rise to a collection of potential ‘marker compounds’; their changes in concentration being correlated to the upgrading process a pyrolysis oil undergoes.

Lee, C., Love, G.D., Jahnke, L.L., Kubo, M.D., Des Marais, D.J., 2019. Early diagenetic sequestration of microbial mat lipid biomarkers through covalent binding into insoluble macromolecular organic matter (IMOM) as revealed by sequential chemolysis and catalytic hydropyrolysis. Organic Geochemistry 132, 11-22.


Analyses of lipids in modern microbial mat ecosystems provide valuable insights into the taxonomic affinities of the dominant biological producers and consumers as well as carbon flow within the mat community. Such microbial mat biomarker assemblages also provide a window into the ancient biomarker record, facilitating paleobiological and paleoenvironmental reconstructions of analogous ecosystems on early Earth. Our focus was to investigate the covalent binding of lipid biomarkers into insoluble macromolecular organic matter (IMOM) during diagenesis in the well-studied hypersaline microbial mat ecosystems and underlying sediments at Guerrero Negro, Baja California Sur, Mexico. Following exhaustive solvent extraction, three different chemical degradation reagents of varying reactivity (acid methanolysis, trichloroacetic acid extraction, and periodate oxidation) were applied to two shallow sedimentary layers prior to fragmentation of the recalcitrant insoluble residues using catalytic hydropyrolysis (HyPy). The hydrocarbons released by HyPy included a complex variety of linear, branched and polycyclic alkane structures, including hopanes, methylhopanes and steranes. Our findings indicate that a significant fraction of the bound biomarker pool was strongly linked by covalent binding through functional groups into IMOM but that a portion of this bound pool was not recoverable by chemolysis treatment. These results provide new insights about the mode and timing of chemical binding of steroids and hopanoids, and their early diagenetic transformation products, into IMOM. The formation of sedimentary IMOM from the earliest stages of organic matter diagenesis, commencing on a timescale of only years, aids the long-term preservation of biomarker lipids in the geological record.

Lee, J.C., Yang, J.S., Moon, M.H., 2019. Simultaneous relative quantification of various polyglycerophospholipids with isotope-labeled methylation by nanoflow ultrahigh performance liquid chromatography-tandem mass spectrometry. Analytical Chemistry 91, 6716-6723.


Herein, we introduce a comprehensive analytical method for the separation and relative quantification of polyglycerophospholipids (PGPLs), including phosphatidylglycerol (PG), bis(monoacylglycero)phosphate (BMP), bis(diacylglycero)phosphate (BDP), Hemi BDP, cardiolipin (CL), monolysocardiolipin (MLCL), and dilysocardiolipin (DLCL), using isotope-labeled methylation (ILM) with nanoflow ultrahigh performance liquid chromatography-electrospray ionization-tandem mass spectrometry (nUHPLC-ESI-MS/MS). Abnormal levels of BMP and CL have been associated with the pathology of lysosomal storage and neurodegenerative diseases. Thus, simultaneous analysis of all PGPLs is important to understand the mechanisms and pathologies of such diseases. In this study, improved separation and MS detection of PGPLs, including their regioisomers, was achieved by the methylation of PGPL. ILM-based relative quantification was applied to lipid extracts from a dopaminergic cell line (SH-SY5Y) treated with drugs commonly used for Parkinson’s disease (PD), resulting in the identification of 229 unique PGPLs, including 121 CLs, 71 MLCLs, and 16 Hemi BDP species. The drug treatment induced significant increases in the amount of CLs containing polyunsaturated fatty acyl chains, including 20:4 and 22:6, as well as decreased levels of BMP, Hemi BDP, and BDP species, demonstrating the feasibility of using ILM for the comprehensive and high-speed relative quantification of PGPLs.



Describing the pore habit of methane hydrate in sediment matrices is essential for understanding natural distribution of methane hydrate, methane trace (transport and solidification) in the hydrate stability zone, physical properties of hydrate-bearing sediments, and the associated influence on potential gas production. Pore habit visualization in natural media at pore scale even with laboratory synthesized cores has been challenging due to the similar densities of methane hydrate from pore liquid. In this work, we used phase-contrast assisted micro-CT with potassium iodine-doped brine to visualize four phases: sand particles, pore fluid, methane hydrate and methane gas. This study visualizes the pore habit of methane hydrate at various stages including during hydrate formation in excess-gas systems, its evolution after brine injection to replace pore fluid, and hydrate formation in excess-water systems. Hydrate tends to adopt round and smooth surfaces when in contact with water while exhibits relatively angular interfaces when in contact with methane gas. Hydrate formation in excess-gas systems results in a partial cementing and partial mineral-coating pore habit, while hydrate in excess-water systems develops mainly as pore-filling, and locally cementing or mineral-coating where big gas pockets exist at the initial state. Pore liquid replacement from methane gas to brine triggers a shift of hydrate pore habit towards pore-filling. Methane hydrate evolution over time produces bigger hydrate particles but with less contact area with sand particles. The effects of hydrate pore habit become less important as hydrate particle size exceeds the pore size. Additionally, hydrate formation could trap residual methane gas and brine as inclusions.

Li, L., Fan, M., Davila, N., Jesmok, G., Mitsunaga, B., Tripati, A., Orme, D., 2019. Carbonate stable and clumped isotopic evidence for late Eocene moderate to high elevation of the east-central Tibetan Plateau and its geodynamic implications. GSA Bulletin 131, 831-844.

https://doi.org/10.1130/B32060.1

The topographic history of mountain belts reflects changes in lithospheric structure and rheology and exerts an influence on climate. Although substantial progress has been made to constrain the growth history of the southern Tibetan Plateau, the timing and geodynamic drivers for surface uplift of the central plateau remain poorly constrained. Here, we used both carbonate clumped isotope geothermometry and modified stable isotope–based paleoaltimetry that considers proportional mixing of two major moisture sources to infer late Eocene paleoelevations of the Nangqian Basin in the east-central Tibetan Plateau. The mean clumped isotope temperature, T(Δ47), of minimally altered late Eocene lacustrine carbonates is 30.0 °C, and the reconstructed least-evaporated paleowater δ18Omw value is –9.8‰. These two independent approaches indicate that during late Eocene time, the Nangqian Basin floor was 2.7 (+0.6/–0.4) km above sea level, and the hypsometric mean elevation of surrounding mountains was 3.0 ± 1.1 km above sea level. These estimates are 1.1–1.2 km lower than their modern counterparts. The moderate to high late Eocene paleoelevation of the Nangqian Basin suggests that Eocene upper-crustal shortening and thickening can explain most, but not all, of the surface uplift of the east-central Tibetan Plateau. The additional 1.1–1.2 km (at most) of post–late Eocene elevation increase to the present height may have been a result of either lower-crustal flow or slab detachment.



CO2 huff-n-puff has been proven to be the most effective enhanced oil recovery (EOR) method in shale oil reservoirs. The injected CO2 will replenish reservoir energy and penetrate the reservoir matrix to extract oil. However, the CO2 sweep volume during the huff-n-puff process has not been accurately evaluated by existing studies. In this paper, the CO2 sweep volume was investigated through experimental and numerical simulation methods. In the experimental study, the CO2 sweep areas were depicted by X-ray computed tomography scan technology. The results indicated that the ratio of the CO2 sweep area was 78.63% in the seventh huff-n-puff cycle, leading to a total oil recovery of 56.80%. The numerical simulation considered the mechanisms of molecular diffusion and nanopore confinement. The results showed that in the first huff-n-puff cycle, the gas sweep volume percentage was 9.47% after 100 days of huff period. In the gas swept volume, oil viscosity was reduced by 25.9% to 68.2%. After three cycles of CO2 injection, the oil recovery manifested a 1.5% increase compared to the case without huff-n-puff. The contributions of different parameters on gas sweep volume and cumulative oil recovery were investigated. The results illustrated that the nanopore confinement effect and molecular diffusion had significant impacts on the gas sweep volume and cumulative oil recovery. Higher injection pressure, longer huff time, and more huff-n-puff cycles lead to larger gas sweep volume, as well as cumulative oil recovery. A suitable primary depletion period and a huff-n-puff schedule should be determined based on the requirements of field production. The investigations in this study provide insights into better understanding of the EOR mechanisms and optimizing the design of CO2 huff-n-puff operations in shale oil reservoirs.



Microbially induced carbonate precipitation (MICP) is one of techniques for consolidation of cementitious materials; however, limited biodiversity and inadequate information on its application suggests further extensive research in this area. In this study, bacteria with ability to precipitate carbonate, preferably CaCO3, were isolated from Yixing Shanjuan Cave, China after analyzing bacterial diversity using Illumina MiSeq sequencing the V3-V4 region of 16S rRNA gene. A total of 58,712 effective 16S rRNA gene sequences were obtained, classified into 31 bacterial phyla. One of the highest urease-producing bacterium, Acinetobacter sp. SC4, was then used in consolidation of cracks created in masonry cement mortars. The bio-consolidation led to significant improvement in compressive strength and reduction in water absorption of mortars. It formed calcite observed under scanning electron microscopy, which were in agreement with X-ray diffraction and thermogravimetric analysis. The presented work is the first extensive study on Acinetobacter sp. induced carbonate precipitation in MICP related research.

Li, P., Yi, L., Liu, X., Hu, G., Lu, J., Zhou, D., Hovorka, S., Liang, X., 2019. Screening and simulation of offshore CO2-EOR and storage: A case study for the HZ21-1 oilfield in the Pearl River Mouth Basin, Northern South China Sea. International Journal of Greenhouse Gas Control 86, 66-81.


CO2-enhanced oil recovery (CO2-EOR) and storage is currently the most effective and economic technology for reducing CO2 emissions from burning fossil fuels in large scale. This paper is the first effort of proposing a modelling assessment of CO2-EOR and storage in the HZ2-1 oilfield in the Pearl River Mouth Basin in northern South China Sea offshore Guangdong Province. We attempt to couple the multi-parameter dimensionless quick screening model and reservoir compositional simulation for optimization of site screen and injection simulation. Through the quick screening, the reservoirs are ranked by EOR dimensionless recovery RD, and by CO2 storage in pore volume SCO2. Our results indicate that SCO2 is highly pressure dependent and not directly related to RD. Of these reservoirs, CO2-EOR and storage potential of the M10 was estimated through a compositional simulation as a case study based on a 3D geological model. Nine scenarios of CO2 injection operations have been simulated for 20 years with different well patterns and injection pressures. The simulation results represent an obvious improvement in oil production by CO2 flooding over No-CO2 production. The best operation for M10 is miscible CO2 flooding, which led to the higher recovery factors of 52%˜58% and CO2 stored masses of 8.1×106˜10.8×106t. The optimum operation for CO2 injection should be set well pattern in region of injector I1 and high injection pressure for miscible flooding. In a whole, the HZ21-1 field can be used as a candidate geological site for GDCCUS project. We are fully aware of the limitation in the primary modelling including reservoir and fluid properties and production history matching, and regard this study as a general and hypothetic proposal.

Li, P., Zou, H., Hao, F., Yu, X., 2019. Sulfate sources of thermal sulfate reduction (TSR) in the Permian Changxing and Triassic Feixianguan formations, northeastern Sichuan Basin, China. Geofluids 2019, Article 5898901.

https://doi.org/10.1155/2019/5898901

Thermal sulfate reduction (TSR) occurred throughout the Permian Changxing (P2c) and Triassic Feixianguan (T1f) dolostone reservoirs in the western and eastern parts of the Kaijiang-Liangping (K-L) trough in the northeastern part of the Sichuan Basin. To determine the sulfate sources of this TSR, fourteen solid bitumen samples and eight anhydrite samples were collected from the northeastern part of the Sichuan Basin. These samples were analyzed to determine their sulfur isotopes. In addition, untreated, HNO3-treated, and CrCl2-treated solid bitumen samples were analyzed to determine their sulfur isotopes in order to obtain reliable δ34S data for the TSR solid bitumen. The results show that the HNO3 method is more effective at removing pyrite from solid bitumen than the method using CrCl2 thrice because the HNO3-treated solid bitumen has lower sulfur contents and higher δ34S. The δ34S of the T1f solid bitumen samples from the Puguang gas field (in the eastern part of the K-L trough, 12.0-24.0‰) is significantly lower than that of the samples from the Yuanba gas field (in the western part of the K-L trough, 24.1-34.2‰). The δ34S of the T1f1–2 anhydrite is 18.1-26.6‰, which is lower than that of the T1f3–4 anhydrite samples (29.9-39.6‰). The TSR sulfates from the Puguang gas field were most likely from the coeval T1f1–2 evaporating seawater and were enriched during the reflux-seepage dolomitization process. The TSR sulfates from the Yuanba gas field were primarily caused by the evaporation of seawater during the T1f4. First, the evaporating seawater would flow vertically into the P2c reservoirs in the adjacent area, and then, it would flow laterally into the P2c reservoirs in the Yuanba gas field. Considering the fact that the sulfate sources of TSR and the δ34S values of the TSR sulfates are different in the Puguang and Yuanba gas fields, the δ34S of TSR solid bitumen cannot be simply used to show the extent of TSR.

Li, S., Wang, X., Mu, W., Han, X., 2019. Chemical signal communication between two protoorganelles in a lipid-based artificial cell. Analytical Chemistry 91, 6859-6864.


The chemical signal communication among organelles in the cell is extremely important for life. We demonstrate here the chemical signal communication between two protoorganelles using cascade enzyme reactions in a lipid-based artificial cell. Two protoorganelles inside the artificial cell are large unilamellar vesicles containing glucose oxidase (GOx-LUVs) and a vesicle containing horseradish peroxidase (HRP) and Amplex red, respectively. The glucose molecules outside the artificial cell penetrate the lipid bilayer through mellitin pores and enter into one protoroganelle (GOx-LUV) to produce H2O2, which subsequently is transported to the other protoorganelle to oxidize Amplex red into red resorufin catalyzed by HRP. The number of GOx-LUVs in an artificial cell is controlled by using a GOx-LUV solution with different density during the electroformation. The reaction rate for resorufin in the protoorganelle increases with more GOx-LUVs inside the artificial cell. The artificial cell developed here paves the way for a more complicated signal transduction mechanism study in a eukaryocyte.

Li, W., Morgan-Kiss, R.M., 2019. Influence of environmental drivers and potential interactions on the distribution of microbial communities from three permanently stratified Antarctic lakes. Frontiers in Microbiology 10, 1067. doi: 10.3389/fmicb.2019.01067.


The McMurdo Dry Valley (MDV) lakes represent unique habitats in the microbial world. Perennial ice covers protect liquid water columns from either significant allochthonous inputs or seasonal mixing, resulting in centuries of stable biogeochemistry. Extreme environmental conditions including low seasonal photosynthetically active radiation (PAR), near freezing temperatures, and oligotrophy have precluded higher trophic levels from the food webs. Despite these limitations, diverse microbial

life flourishes in the stratified water columns, including Archaea, bacteria, fungi, protists and viruses. While a few recent studies have applied next generation sequencing, a thorough understanding of the MDV lake microbial diversity and community structure is currently lacking. Here we used Illumina MiSeq sequencing of the 16S and 18S rRNA genes combined with a microscopic survey of key eukaryotes to compare the community structure and potential interactions among the bacterial and eukaryal communities within the water columns of Lakes Bonney (east and west lobes, ELB and WLB, respectively) and Fryxell (FRX). Communities were distinct between the upper, oxic layers and the dark, anoxic waters, particularly among the bacterial communities residing in WLB and FRX. Both eukaryal and bacterial community structure was influenced by different biogeochemical parameters in the oxic and anoxic zones. Bacteria formed complex interaction networks which were lake-specific. Several eukaryotes exhibit potential interactions with bacteria in ELB and WLB, while interactions between these groups in the more productive FRX were relatively rare.



Leaf-wax n-alkane hydrogen isotope composition (δDalk) is widely applied as a proxy for paleohydroclimatic changes, but the factors controlling δDalk remain to be clarified. In this study, in order to determine the dominant controls, we measured δDalk in 54 surface soils along a southeast–northwest transect across a steep climatic gradient in China. δDalk is positively correlated with annual precipitation δD (δDpann) and better correlated with growing season (April–October) precipitation δD (δDpgs). However, the variability of δDpann (38‰) and δDpgs (35‰) does not explain all of the variance in δDalk (84‰). The apparent fractionation of hydrogen isotopes between n-alkanes and precipitation (εalk/p) is significantly correlated with variables related to aridity: relative humidity, rainfall amount, and aridity index (defined as the ratio of average precipitation to average potential evapotranspiration). This result demonstrates the important control of aridity on δDalk, which may result from the increasing soil evaporation and plant transpiration, as well as decreasing biosynthetic fractionation, in arid climates. We compiled published δDalk data from surface lake/soil sediments in China, and found that aridity effects are pronounced in regions with mean annual precipitation (MAP) < 800 mm. Therefore, we suggest that soil δDalk reflects precipitation δD modified by aridity, with a greater degree of modification in arid environments (e.g., MAP < 800 mm). Future work to quantitatively determine the effects of aridity on δDalk is needed to improve the reliability of the application of δDalk in paleoenvironmental studies.



Primary production of less than 25% of original gas in place (OGIP) may be elevated by enhanced shale gas recovery (ESGR) using either pure CO2 or N2 as injected stimulants. Alternatively, injecting mixtures of CO2 and N2 may potentially optimize recovery of natural gas and beneficially sequester CO2. We develop a dual-porosity, dual-permeability finite element (FEM) model coupled with multi-component gas flow and sorption behavior to 1) explore the evolution of sorption-induced strain resulting from competitive adsorption and its influence on the matrix and fracture permeability; 2) define cumulative production of CH4 and 3) evaluate the amount of CO2 sequestered in the reservoir; Results show that pure-CO2 injection can increase shale gas recovery by ∼20%. Conversely, pure-N2 injection can increase shale gas recovery by ∼80%. Injecting mixtures of CO2 and N2 can increase

shale gas recovery between these end-member magnitudes of ∼20%–∼80% depending on the gas composition. We show that a higher proportion of CO2 in the injected CO2–N2 mixture will result in the decreased recovery of shale gas. However, at the same injection pressure, injecting CO2–N2 mixtures with a higher proportion of CO2 does not always result in more CO2 sequestered in the reservoir. Indeed, when the CO2 injection ratio is >70%, as explored in this study, increasing the CO2 injection ratio will result in less CO2 sequestered. This is because, as the CO2–N2 gas ratio increases, shale gas recovery decreases and results in more CH4 left in the reservoir to compete with CO2 for sorption sites and finally resulting in less CO2 sequestered.

Li, Z., Huang, H., He, C., Fang, X., 2019. Maturation impact on polyaromatic hydrocarbons and organosulfur compounds in the Carboniferous Keluke Formation from Qaidam Basin, NW China. Energy & Fuels 33, 4115-4129.


A maturity sequence from the Keluke Formation of the Upper Carboniferous marine–continental transitional depositional environment in the Qaidam basin, NW China has been geochemically characterized by bulk and molecular compositions, especially the behavior of polyaromatic hydrocarbons and organosulfur compounds. Some commonly used maturity parameters such as the methylnaphthalene ratio (MNR), the dimethylnaphthalene ratio (DNR), the methylphenanthrene ratio (MPR), methylphenanthrene index-3 (MPI-3), dimethylphenanthrene index-2 (DMPI-2), the methyldibenzothiophene ratio (MDR) and dimethyldibenzothiophene (DMDBT) ratios (4,6-/1,6- + 1,8- + l,4-DMDBT and 2,4-/1,6- + 1,8- + l,4-DMDBT), Rock-Eval Tmax, and measured vitrinite reflectance (%Ro) increase gradually with burial depth, whereas others such as the trimethylnaphthalene ratio (TMNr), the tetramethylnaphthalene ratio (TeMNr), MPI-1, and DMPI-1 show no correlation with these maturity indicators. The calculated equivalent Ro values from MPR and MDR based on empirical correlation reported in the literature overestimate the maturity level. The degree of alkylation plays a dominant role in molecular compositional variation and maturity parameter validity, which is in turn controlled by the nature of organic input, depositional environment, and lithology rather than solely controlled by maturation. Dealkylation of alkylnaphthalenes at Ro ∼ 1.0% removes most thermally unstable isomers from C3- and C4 homologues, which makes parameters based on them lose sensitivity. The proportion of phenanthrene varies greatly in the marine–continental transitional depositional system and the involvement of phenanthrene in the formulation makes MPI-1 and DMPI-1 fail to reflect the maturity level. Overestimation of the maturity level based on the degree of isomerization is caused by a high catalytic effect in the marine–continental transitional depositional system, which facilitates isomerization and dealkylation processes.

Liang, F., Zhang, J., Liu, H.-H., Bartko, K.M., 2019. Multiscale experimental studies on interactions between aqueous-based fracturing fluids and tight organic-rich carbonate source rocks. SPE Reservoir Evaluation & Engineering 22, 402-417.

https://doi.org/10.2118/192411-PA

Hydraulic fracturing has been widely used for unconventional reservoirs, including organic-rich carbonate formations, for oil and gas production. During hydraulic fracturing, massive amounts of fracturing fluids are pumped to crack open the formation, and only a small percentage of the fluids are recovered during the flowback process. The negative effects of the remaining fluid on the formation, such as clay swelling and reduction of rock mechanical properties, have been reported in the literature. However, the effects of the fluids on source-rock properties—especially on

microstructures, porosity, and permeability—are scarcely documented. In this study, microstructure and mineralogy changes induced in tight carbonate rocks by imbibed fluids and the corresponding changes in permeability and porosity are reported.

Two sets of tight organic-rich carbonate-source-rock samples were examined. One sample set was sourced from a Middle East field, and the other was an outcrop from Eagle Ford Shale that is considered to be similar to the one from the Middle East field in terms of mineralogy and organic content. Three fracturing fluids—2% potassium chloride (KCl), 0.5 gal/1,000 gal (gpt) slickwater, and synthetic seawater—were used to treat the thin section of the source-rock and core samples. Modern analytical techniques, such as scanning electron microscopy (SEM) and energy-dispersive spectroscopy (EDS), were used to investigate the source-rock morphology and mineralogy changes before and after the fluid treatment, at the micrometer scale. Permeability as a function of effective stress was quantified on core samples to investigate changes in flow properties caused by the fracturing-fluid treatments.

The SEM and EDS results before and after fracturing-fluid treatments on the source-rock samples showed the microstructural changes for all three fluids. For 2% KCl and slickwater fluid, reopening of some mineral-filled natural fractures was observed. The enlargement of the aperture for pre-existing microfractures was slightly more noticeable for samples treated with 2% KCl compared with slickwater at the micrometer scale. In one sample, dissolution of organic matter was captured in the slickwater-fluid-treated rock sample. Mineral precipitation of sodium chloride (NaCl) and generation of new microfractures were observed for samples treated with synthetic seawater. The formation of new microfractures and the dissolution of minerals could result in increases in both porosity and permeability, whereas the mineral deposition would result in permeability decrease. The overall increase in absolute gas permeability was quantified by the experimental measurements under different effective stress for the core-plug samples. This effect on absolute-gas-permeability increase might have an important implication for hydrocarbon recovery from unconventional reservoirs.

This study provides experimental evidence at different scales that aqueous-based fracturing fluid might potentially have a positive effect on gas production from organic-rich carbonate source rock by increasing absolute gas permeability through mineral dissolution and generation of new fractures or reopening of existing microfractures. This observation will be beneficial to the future use of freshwater-and seawater-based fluids in stimulating gas production from organic-rich carbonate formations.

Lin, S.-Y., Wang, Y.-C., Hsiao, C., 2019. Prebiotic iron originates the peptidyl transfer origin. Molecular Biology and Evolution 36, 999-1007.

https://doi.org/10.1093/molbev/msz034

The ribosome is responsible for protein synthesis in all living organisms. It is best known to exist around 3.5–3.7 Ga whereat life on Earth inhabited anoxic environment with abundant soluble irons. The RNAs and proteins are the two biopolymers that constitute the ribosome. However, both proteins and RNAs require metal cations to fold and to function. There are four Mg-microcluster (Mg2+-μc) structures conserved in core of large subunit, and the 23S ribosomal RNA (rRNA) was shown to catalyze electron transfer in an anoxic environment in the presence of Fe2+. The Mg2+-μc features two idiosyncratic Mg2+ ions that are chelated and bridged by a common phosphate group and along with that, the adjacent residues of RNA backbone together forming ten-membered chelation ring(s). Here, we utilized four rRNA fragments of the large subunit 23S rRNA of Haloarcula marismortui, that includes the residues that form the four Mg2+-μc’s. These four rRNA fragments are shown competent to assemble with Mg2+. Our results show that when these rRNA fragments fold or assembly in the

presence of Fe2+ under anoxic conditions, each Fe2+-microcluster can catalyze electron transfer. We propose that Fe2+-microclusters of the ribosome, which use Fe2+ as a cofactor to regulate electron transfer, are pivotal and primordial and may be an origin in evolution of the ribosome.

Liu, C., Liu, K., Wang, X., Wu, L., Fan, Y., 2019. Chemostratigraphy and sedimentary facies analysis of the Permian Lucaogou Formation in the Jimusaer Sag, Junggar Basin, NW China: Implications for tight oil exploration. Journal of Asian Earth Sciences 178, 96-111.


The middle Permian Lucaogou Formation (P2l) in the Jimusaer Sag of the southeastern Junggar Basin, NW China hosts China’s first commercial tight (shale) oil production. Two tight-oil sweet spot intervals have been identified within the P2l formation. Coupled chemostratigraphic and sedimentary facies analysis reveals that the sweet spot intervals were deposited in deep–shallow saline lacustrine to nearshore environments under an overall dry climate setting. The sweet spot intervals in the P2l formation comprises several chemostratigraphically and lithologically distinct units deposited under the influence of subtle climatic and environmental changes that have previously not been recognized. A total of 11 depositional units have been identified within the two sweet spot intervals based on an Integrated Prediction Error Filter Analysis (INFEFA) of Gamma Ray logs and environmental parameters derived from chemostratigraphic data. The tight oil reservoir sweet spot intervals were found to be controlled by the spatial and temporal distribution of total organic carbon (TOC) and reservoir properties (e.g., porosity and permeability) and source-reservoir coupling. Two potential tight oil exploration plays are recognized, including those depositional units with porous reservoir beds interbedded with high-TOC source beds (a self-generation play), and those units with porous reservoir beds adjacent to high-TOC source beds (a near-source play).



A combined bulk and position-specific isotope study was conducted on natural gases collected from an unconventional gas field in the Late-Devonian to Early Mississippian Woodford Shale in the southwestern Arkoma Basin in Oklahoma. The set of natural gases records a hitherto underreported case, where gases become wetter with decreasing isotope compositions in an early stage of maturation. A first dataset of position-specific isotope compositions of propane with demonstrated accuracy and precision show that while the bulk δ2H values of propane increased by 30‰ with maturity, position-specific hydrogen isotope deviations of propane (Δ2-1) increased by 80‰. Position-specific δ2H values showed that δ2H values of the central H in propane increased by 70‰ with maturity, but those of terminal H in propane remained constant. This contrasting behavior could have resulted from the hydrogen isotope exchange between shale water and propane with a half-time of the center H, varying strongly from ∼310 to ∼6 m.y. at ∼140–185 °C. On the other hand, bulk and position-specific δ13C values of propane remain nearly constant during the maturation. Position-specific isotope compositions of propane at the highest maturity yield an equilibrium temperature that is consistent with its maturity, thus possibly serving as single-compound isotope geothermometry.


https://onlinelibrary.wiley.com/doi/abs/10.1002/mbo3.715

The growth of all methanogens is limited to a specific temperature range. However, Methanothermobacter thermautotrophicus can be found in a variety of natural and artificial environments, the temperatures of which sometimes even exceed the temperature growth ranges of thermophiles. As a result, the extent to which methane production and survival are affected by temperature remains unclear. To investigate the mechanisms of methanogenesis that Archaea have evolved to cope with drastic temperature shifts, the responses of Methanothermobacter thermautotrophicus to temperature were investigated under a high temperature growth (71°C) and cold shock (4°C) using Isobaric tags for relative and absolute quantitation (iTRAQ). The results showed that methane formation is decreased and that protein folding and degradation are increased in both high‐ and low‐temperature treatments. In addition, proteins predicted to be involved in processing environmental information processing and in cell membrane/wall/envelope biogenesis may play key roles in affecting methane formation and enhancing the response of M. thermautotrophicus to temperature stress. Analysis of the genomic locations of the genes corresponding to these temperature‐dependent proteins predicted that 77 of the genes likely to form 32 gene clusters. Here, we assess the response of M. thermautotrophicus to different temperatures and provide a new level of understanding of methane formation and cellular putative adaptive responses.



It is widely concerned that the adsorbed natural surface-active components at the interface between crude oil and produced water form a protective layer to prevent emulsion from instability. Asphaltenes and resins are considered to perform significant roles among these natural surface-active components in the crude oil. This study deals with the effect of the interactions between asphaltenes and resins on water/oil interfacial properties and emulsion stability. Firstly, the dynamic surface pressure of asphaltenes and resins are obtained with the shape analysis method of pendant droplet, respectively. A synergetic effect of asphaltenes and resins is confirmed by comparing the dynamic surface pressure of the binary system with that of the single system. The addition of resins enhances the interfacial affinity of asphaltenes at the beginning of the adsorption. Asphaltenes have stronger influence than resins in the long-term adsorption. Then, the dilational modulus is measured with the method of interfacial small-amplitude oscillation. The addition of resins reduces the dilational modulus, weakening the structural strength of interfacial layer. Conductivity experiments are carried out to determine the dispersed state of asphaltenes. Due to the synergetic effect of asphaltenes and resins, adding resins motivates the dispersal of asphaltenes, thus changing the turning point of conductivity to higher proportion of n-heptane. At last, emulsion stability experiments are performed to back up the synergetic effect occurred at the interface. The addition of resins increases the stability of emulsion at initial time. However, the emulsion stability is deteriorated when the resins are excessive. Similar to the adsorption phenomenon at the interface, resins have slighter impacts on emulsion stability in the long term. Asphaltenes still possess a dominated position in determining the emulsion stability.

Liu, G., Qu, Y., 2019. Engineering of filamentous fungi for efficient conversion of lignocellulose: Tools, recent advances and prospects. Biotechnology Advances 37, 519-529.


Filamentous fungi, as the main producers of lignocellulolytic enzymes in industry, need to be engineered to improve the economy of large-scale lignocellulose conversion. Investigation of the cellular processes involved in lignocellulolytic enzyme production, as well as optimization of enzyme mixtures for higher hydrolysis efficiency, have provided effective targets for the engineering of lignocellulolytic fungi. Recently, the development of efficient genetic manipulation systems in several lignocellulolytic fungi opens up the possibility of systems engineering of these strains. Here, we review the recent progresses made in the engineering of lignocellulolytic fungi and highlight the research gaps in this area.

Liu, H., Raffin, G., Trutt, G., Dugas, V., Demesmay, C., Randon, J., 2019. Hyphenation of short monolithic silica capillary column with vacuum ultraviolet spectroscopy detector for light hydrocarbons separation. Journal of Chromatography A 1595, 174-179.


Compared to conventionnal bench top instruments, on-line GC analyzers require specific characteristics. On one hand, for some applications operating with a reactor pressure as high as several tens of bars, sample pressure has to be reduced before GC separation, or specific valves and columns have to be designed to perform separation with high carrier gas inlet pressure. On the other hand, informative detectors such as mass spectrometer are valuable but low maintenance detectors are prefered. To fit these two requirements (sampling at high pressure without decompression stage, and informative detector with low maintenance), short monolithic silica capillary column operated with inlet pressure as high as 60 bar has been hyphenated to VUV detector. Injection and column performance have been first investigated. The system has been optimized by adjusting split ratio at high pressure and by tuning two main VUV detector parameters (“average number” linked to data point averaging and make-up gas pressure) to decrease the limit of quantification. The optimization stage led to a set of experimental parameters which is a good compromise between signal-to-noise ratio and chromatographic efficiency. Finally, the hyphenated monolithic column has be used to partially separate a mixture of methane, ethane, carbon monoxide and carbon dioxide within 15 s, and the VUV deconvolution capabilities have been exploited to overcome coelution and finally separate individual signals.



Significant quantities of tight gas resources have been discovered in the Upper Paleozoic interval in the Ordos Basin, central China. The gas is believed to have been derived primarily from the Upper Paleozoic coal, mudstone and limestone source rocks. An integrated organic geochemistry and basin modeling approach was applied to quantitatively evaluate gas generation from the three types of source rocks. Source-specific gas generation kinetics were first established on the basis of sealed gold tube pyrolysis experiments. Gas generation was then modeled in 1D and 3D using the source-specific kinetics obtained. The results show that (1) near the depositional and thermal center (e.g., Well ZT-1),

gas generation occurred much earlier and was greater than that of the Sh-360 well, which is away from the depositional and thermal center; (2) C2-C5 gases in the ZT-1 well underwent thermal cracking, while gases in the Sh-360 well did not experience any secondary thermal alteration; (3) hydrocarbon gases were mainly generated during the Early Cretaceous (135–96 Ma) and the Late Jurassic (161–135 Ma); (4) the cumulative amounts of gas generation from the coal, mudstone and limestone source rocks are 147.23 × 1012, 57.85 × 1012 and 12.73 × 1012 m3, respectively, with coal seams being a major contributor (about 67.6%) to the Upper Paleozoic gas system, followed by the mudstone (about 26.6%) and limestone (about 5.8%). By comparing with previous work and a default kinetics basin model, our source-specific kinetics basin model is more suitable for simulating gas generation in the Upper Paleozoic source rocks within the Ordos Basin.

Liu, J., Song, J., Yuan, H., Li, X., Li, N., Duan, L., 2019. Biogenic matter characteristics, deposition flux correction, and internal phosphorus transformation in Jiaozhou Bay, North China. Journal of Marine Systems 196, 1-13.


Sediment resuspension in coastal environments is associated with both nutrient repartitioning and with the biological carbon pump, which are further linked to climate change, eutrophication, and marine pollution. To explore these relationships, a resuspension framework, including surficial/core sediments and settling trap-collected particles (TCPs), was assessed in the Jiaozhou Bay (JZB) to examine the behavior and fate of particulate biogenic elements (C, N, P and Si). Resuspension-mediated differences in the concentrations of numerous biogenic proxies were significant and mainly corresponded to selective upwelling of fine-sized, nutrient-enriched particles, to autochthonous organic matter degradation below the trap-deployed level comprising water column transportation and long-term retention at the sediment-water interface. This is further reinforced by smaller inorganic carbon concentrations in sediments and origin-indicating stoichiometric ratio records (OC:ON, OC:OP). Nevertheless, biogenic silica (BSi) exhibited a near homologous concentration and had the largest preservation efficiency. Three principal components, representing production and preservation, remineralisation, and a particle-size effect, accounted for 55.5%, 14.0%, and 9.1% of the total variance, respectively. After calibration, the primary sinking flux was two orders of magnitude smaller than the measured absolute sedimenting flux. Also, the limited bottom achieving contribution with a maximum of 28.3% for freshly biogenic particles produced in autumn/winter circumstances with low primary productivity was inferred. The recurrent resuspension processes in JZB demonstrated that 5–12 cycles of similar or higher intensity resuspension was required before freshly-formed biogenic particles could ultimately be integrated into the sediments. Regarding the internal P sink-switching mechanism, the previously transformed Fe-bound fraction across the estuarine salinity gradient has limited application under offshore redox oscillations, whereas near-quantitative transfer of dissolved P from remineralized organic matter to authigenic carbonate fluorapatite could substantially reduce its bio-availability in resuspended particulate P.

Liu, J., Zheng, Y., Lin, H., Wang, X., Li, M., Liu, Y., Yu, M., Zhao, M., Pedentchouk, N., Lea-Smith, D.J., Todd, J.D., Magill, C.R., Zhang, W.-J., Zhou, S., Song, D., Zhong, H., Xin, Y., Yu, M., Tian, J., Zhang, X.-H., 2019. Proliferation of hydrocarbon-degrading microbes at the bottom of the Mariana Trench. Microbiome 7, Article 47.

https://doi.org/10.1186/s40168-019-0652-3

Background: The Mariana Trench is the deepest known site in the Earth’s oceans, reaching a depth of ~ 11,000 m at the Challenger Deep. Recent studies reveal that hadal waters harbor distinctive

microbial planktonic communities. However, the genetic potential of microbial communities within the hadal zone is poorly understood.

Results: Here, implementing both culture-dependent and culture-independent methods, we perform extensive analysis of microbial populations and their genetic potential at different depths in the Mariana Trench. Unexpectedly, we observed an abrupt increase in the abundance of hydrocarbon-degrading bacteria at depths > 10,400 m in the Challenger Deep. Indeed, the proportion of hydrocarbon-degrading bacteria at > 10,400 m is the highest observed in any natural environment on Earth. These bacteria were mainly Oleibacter, Thalassolituus, and Alcanivorax genera, all of which include species known to consume aliphatic hydrocarbons. This community shift towards hydrocarbon degraders was accompanied by increased abundance and transcription of genes involved in alkane degradation. Correspondingly, three Alcanivorax species that were isolated from 10,400 m water supplemented with hexadecane were able to efficiently degrade n-alkanes under conditions simulating the deep sea, as did a reference Oleibacter strain cultured at atmospheric pressure. Abundant n-alkanes were observed in sinking particles at 2000, 4000, and 6000 m (averaged 23.5 μg/gdw) and hadal surface sediments at depths of 10,908, 10,909, and 10,911 m (averaged 2.3 μg/gdw). The δ2H values of n-C16/18 alkanes that dominated surface sediments at near 11,000-m depths ranged from − 79 to − 93‰, suggesting that these sedimentary alkanes may have been derived from an unknown heterotrophic source.

Conclusions: These results reveal that hydrocarbon-degrading microorganisms are present in great abundance in the deepest seawater on Earth and shed a new light on potential biological processes in this extreme environment.

Liu, P., Sun, S.Z., Hu, L., 2019. Estimation of gas hydrate saturation at the slope in the northwest of South China Sea. Petroleum Science and Technology 37, 1777-1787.

https://doi.org/10.1080/10916466.2019.1594289

Lack of drilling and inversion data is therefore difficult to calculate hydrate saturation in the region of interest. There remains no effective solution in the literature. This study combines the method of impedance index calculation and one-dimensional forward modeling to estimate the upper and lower limits of hydrate saturation. In the current work, the calculation of hydrate saturation includes three steps: (1) The relationship between hydrate saturation and P-wave impedance by equivalent medium theory is established and then is converted into the relationship between hydrate saturation and impedance index. (2) Impedance index of water-bearing and hydrate formation is obtained from the velocity model based on the forward modeling. (3) The upper and lower limits of hydrate saturation are obtained by plugging in the impedance index into the equation of hydrate saturation. This method is just apt for the situation with the range of porosity from 30% to 70%, velocity of matrix grains from 30% to 70%, and in-phase reflections. This study demonstrates that the upper and lower limits of hydrate saturation can be obtained in the region lack of drilling and inversion data.



The adsorption of nanoparticles onto mineral surfaces is a major limitation for applications that require long transport distances, such as enhanced oil recovery. This study investigates silica nanoparticle transport and adsorption in long granular columns, with emphasis on the adsorption onto

carbonate substrates, given the fact that carbonate reservoirs host more than 60% of the world’s recoverable oil. The grain-scale particle–mineral interactions are characterized by zeta potential measurements. Ionic strength (especially potential-determining ions: Ca2+, Mg2+, CO3

2–, etc.) inherently influences the zeta potential of carbonates. Derjaguin–Landau–Verwey–Overbeek analyses show that low surface potential and high ionic concentration inhibit the electrostatic double-layer repulsion and lower the energy barrier of adsorption. Adsorption column experiments simulate a variety of fluid chemistry conditions: pH, ionic concentration, and ion type. Alkaline and low-salinity conditions favor silica nanoparticles transport in carbonate reservoirs. Both scanning electron microscopy images and adsorption mass analyses suggest that the adsorption of nanoparticles onto carbonate substrates is multilayered. A two-term adsorption model adequately captures the instantaneous adsorption and the subsequent kinetic adsorption. The instantaneous adsorption constant delays particle transport, and the kinetic adsorption rate determines the concentration profile of nanoparticles along the reservoir at the steady state. High advection velocity and low adsorption rate k1 are required to deliver high nanoparticle concentration to the far field in the reservoir.

Liu, R., Gou, R., Pu, W.-f., Ren, H., Du, D.-j., Chen, P., Mei, Z.-l., 2019. Visual laminations combined with nuclear magnetic resonance to study the micro-unrecovered oil distribution and displacement behavior of chemical flooding in a complex conglomerate. Energy & Fuels 33, 4041-4052.


The conglomerate reservoirs of the Kexia group, Xinjiang oilfield, NW China, are one of the largest conglomerate reservoirs worldwide and have employed chemical-enhanced oil recovery (EOR) processes since the 2010s. However, compared to sandstone reservoirs, the output of chemical flooding has been less than 2.0% because of the severe heterogeneity and complex fluid distribution. This study quantitatively examined the micro-unrecovered oil distribution and displacement behavior of polymer flooding in the complex conglomerate of the Kexia group by combining visual conglomerate laminations and online nuclear magnetic resonance experiment. The results indicated that the multistream sedimentary environments and the rapid transport of the clasts prior to deposition exacerbated the complexity of nonclay minerals and variable pore-throat structures. Compared to the sandstone, the variable pore channels and disconnected seepage network in the conglomerate caused macro-permeable water channels and rapid water cuts, resulting in the recovery of less than 40% of original oil in place (OOIP) by the earlier water flooding. The cluster of disconnected oil and oil resident in blind pores occupied a major proportion of unrecovered oil, which was the significant target for the polymer flooding. The data from the T2 responses showed that the polymer solution first navigated through dominant porous media, while simultaneously building flow resistance in the higher permeability zones. The remaining oil in the disconnected oil cluster and the four types of residual oil (ganglia- and column-type oils, oil film, and oil resident in blind pores) were effectively displaced by the viscoelastic effects of the polymer solution. In addition, star-like polyacrylamide (SHPAM) has a higher pore space utilization compared to partially hydrolyzed polyacrylamide. For SHPAM, the incremental oil recovery factor was approximately 25% with an ultimate recovery factor of 64.2% OOIP. This work implies that the lower oil recovery efficiency of water flooding gives rise to a significant potential for chemical-EOR processes in complex conglomerates.

Liu, S., Peng, X., 2019. Organic matter diagenesis in hadal setting: Insights from the pore-water geochemistry of the Mariana Trench sediments. Deep Sea Research Part I: Oceanographic Research Papers 147, 22-31.


The diagenetic processes of organic matter (OM) in hadal sedimentary environments (>6000 m water depth) are much less studied than those in other accessible environments. In this study, we quantify OM oxidation processes using pore-water geochemical measurements, fluxes, and diagenetic rate calculations in sediments along a depth transect from abyssal to hadal sites (5500–10257 m) in the Mariana Trench. The total benthic O2 consumption, and depth-integrated rates of nitrification and denitrification are positively correlated with water depth, indicating that OM diagenesis is enhanced in the deep sites of the hadal zone. The negative linear correlation between water depth and oxygen/nitrate penetration depths further supports this conclusion. In the abyssal sites, aerobic respiration dominates OM degradation, and anaerobic processes are negligible. In contrast, denitrification plays an important role in anaerobic OM degradation, and accounts for approximately 5% of the depth-integrated total OM mineralization at the deepest hadal site. Moreover, our results suggest that direct coupling between nitrification and denitrification is significant, and may define the turnover of N in hadal sediments. Although they are not without uncertainties, our results shed new light on the importance of denitrification in sedimentary diagenesis in the deepest part of the Earth's ocean, and could have important implications for understanding the current state of biogeochemical cycles in the hadal zone.

Liu, W., Song, Q., Cao, Y., Zhao, Y., Huo, H., Wang, Y., Song, Y., Li, J., Tu, P., 2019. Advanced liquid chromatography-mass spectrometry enables merging widely targeted metabolomics and proteomics. Analytica Chimica Acta 1069, 89-97.


Either widely targeted metabolomics or quantitative proteomics usually requires unique analytical platform. However, cross-platform omics studies entail higher levels of complexity and uncertainty, and result in a significant obstacle for high throughput assay as well. It is thereby urgent to pursue an integrative approach being capable of merging these two omics terms, namely widely targeted bi-omics. As an eligible analytical tool for large-scale targeted metabolomics, reversed phase liquid chromatography-hydrophilic interaction liquid chromatography–tailored selected reaction monitoring (RPLC-HILIC–tailored SRM) was deployed here to further receive the tryptic peptides as the analytes. Comparative evaluation of metabolites and tryptic peptides, 101 ones in total, between HepG2 and SK-Hep1 cells was conducted as a proof-of-concept. All analytes, regardless of metabolites or peptides, exhibited satisfactory chromatographic behaviors on RPLC-HILIC. Quantitative MS parameters, such as SRM transitions and collision energies (CEs), of either tryptic peptides or metabolites were online optimized in a standard compound-independent manner. It was worthwhile to mention that the signal responses of the peptides-of-choice generated by the optimized CEs were significantly superior to those values suggested by Skyline software. Calibration curves of both metabolites and peptides were constructed by serially diluting a so-called universal metabolome standard (UMS) sample. The quasi-content of each peptide or metabolite was gained according to applying those regressive calibration curves. After subjecting the quasi-content dataset into SIMCA-P software, significant differences took place between the two hepatic cell lines, and not only metabolites but tryptic peptides contributed to the discrimination. Above all, RPLC-HILIC–tailored SRM offered a promising choice towards widely targeted bi-omics attributing to the advantage of simultaneous monitoring metabolites and tryptic peptides.

Liu, X., Chu, G., Du, Y., Li, J., Si, Y., 2019. The role of electron shuttle enhances Fe(III)-mediated reduction of Cr(VI) by Shewanella oneidensis MR-1. World Journal of Microbiology and Biotechnology 35, Article 64.

https://doi.org/10.1007/s11274-019-2634-9

Chromate is one of the hazardous toxic pollutants. Reduction of Cr(VI) to Cr(III) has shown to reduce the toxicity of chromate. This work examined the reduction of Cr(VI) using an anaerobic batch cultures of Shewanella oneidensis MR-1 containing Fe(III). To do so, 10 mg/L Cr(VI) was reduced to Cr(III) within 3 days along with the oxidization of Fe(II) to Fe(III). The removal rate of Cr(VI) increased with increasing the concentration of Fe(III). In the absence of Cr(VI), the Fe(II) concentration of the batch culture increased with the growth of S. oneidensis MR-1. These data showed that S. oneidensis MR-1 could reduce Fe(III) into Fe(II), resulting in reduction of Cr(VI) to Cr(III). During this process, the anthraquinone-2,6-disulfonate (AQDS) acted as an electron shuttle. Microscopic analysis showed that Cr(VI) had toxic effects on S. oneidensis MR-1 due to the appearance of Cr species on the bacterial surface. Cr2O3 or Cr(OH)3 precipitates formed during Cr(VI) reduction was identified using X-ray photoelectron spectroscopy. The AQDS as an electron shuttle enhanced the Cr(VI) reduction by S. oneidensis MR-1. Microbial reduction of Cr(VI) can be a useful technique for Cr detoxification.

Liu, X., Feng, X., Sun, Y., Chen, Y., Tang, Q., Zhou, X., Dong, L., Fan, S., Jiao, P., Wang, K., Wen, W., Lu, B., 2019. Acoustic and biological characteristics of seafloor depressions in the North Yellow Sea Basin of China: Active fluid seepage in shallow water seafloor. Marine Geology 414, 34-46.


High resolution multibeam bathymetry revealed the occurrence of numerous craterlike depressions, so-called pockmarks, in the sea floor of the North Yellow Sea Basin (NYSB). To investigate whether these pockmarks are related to any type of fluid flow or gas seepage from subsurface stratum, acoustic survey and box samplings were conducted in a selected area containing several typical pockmarks. This allowed for an integrated analysis of the morphology, distribution, and subsurface strata as well as a direct comparison of seafloor characteristics among different areas inside and outside of a pockmark. Additionally, surface sediments were analyzed for particle structure and grain size. Based on the combination of multibeam bathymetry and backscatter intensity data, 282 seafloor depressions were accurately identified. Moreover, the formation of pockmark can be attributed to existence of gas chimneys and other shallow gases revealed by shallow seismic profile records in the subsurface strata. Sediments inside and outside the pockmark showed remarkable discrepancies in terms of grain size, and benthic fauna. Additionally, strong internal reflection area was observed inside the depressions where benthic habitats are abundant and sediments contain strawberry pyrite and carbonate cementation. Side scan sonar also recorded sediment plumes in the water column, which indicates that the pockmarks are still active. Several “pearl-string-like” accumulations of pockmark were found in the study area, which well agree with the distribution of buried channels and lakes. These results thus provide new insights in interpreting shallow water fluid seepage, with implications for our current knowledge of overall sedimentation process in offshore continental shelves.



Quantitative characterization of nanopore structure is of great importance for both accurate assessment of gas reservoir capacity and gas migration behaviors. In this work, atomic force microscopy (AFM) experiments were performed on coal and coal-bearing shale samples, attempting to gain clearer insights into the nanopore characteristics and surface roughness. Scanning electron microscopy (SEM) and low pressure N2 gas adsorption (LP-N2GA) were used for qualitative and

quantitative comparative analysis, respectively. SEM results are found in good accordance with AFM surface topographies. The values of Ra are 18.04, 7.24 and 14.17 nm for Coal-1, Coal-2 and shale, respectively. The obtained similar nanopore distribution curves via LP-N2GA and AFM indicate that the nanoporosity determined by AFM is reliable. However, the differences between these two methods can not be neglected. The percentage of nanopores with diameter <4 nm generated from LP-N2GA are higher than that rendered from AFM for both coal and shale samples, due to the gas adsorption-induced swelling, but it is reverse for macropore (>200 nm). AFM is a high-resolution tool for nanopore characterization, and it is expected to be widely used for quantitative analysis of porous media.

Liu, Y., Ma, X., Li, H.A., Hou, J., 2019. Competitive adsorption behavior of hydrocarbon(s)/CO2 mixtures in a double-nanopore system using molecular simulations. Fuel 252, 612-621.


CO2 injection into shale reservoirs has been recently proposed as a promising method that can be used to enhance hydrocarbon recovery from shale reservoirs. Adsorption behavior of hydrocarbon(s)/CO2 mixtures under shale-reservoir conditions plays an important role in affecting the efficiency of CO2-enhanced hydrocarbon recovery from shale. In organic pores residing in shale reservoirs, the adsorption behavior of hydrocarbon(s)/CO2 mixtures can be significantly affected by the strong fluid/pore-wall interactions. In this work, a double-nanopore system comprising of two pores with sizes of 1 nm and 3 nm is built; then the competitive adsorption behavior of hydrocarbon(s)/CO2 mixtures (i.e., C1/nC4, C1/CO2, nC4/CO2, and C1/nC4/CO2 mixtures) is investigated in this double-nanopore system using the molecular dynamic (MD) simulations. Firstly, the competitive adsorption behavior of C1/nC4 mixture in double-nanopore system is studied with a depressurization manner. The effects of pressure and pore size distribution on competitive adsorption between hydrocarbons and CO2 are discussed. To investigate the efficiency of CO2 in replacing C1 or nC4 molecules from organic pores, dynamic distribution characteristics of C1/CO2, nC4/CO2, and C1/nC4/CO2 mixtures in the double-nanopore system are further investigated. The competitive adsorption behavior of C1/nC4 mixture indicates that, in both nanopores, as pressure decreases, adsorption of lighter hydrocarbon (i.e., C1) decreases significantly, but adsorption of heavier component (i.e., nC4) increases slightly. It suggests that as pressure decreases, the lighter hydrocarbons can be easily extracted from nanopores, while the heavier hydrocarbons may not be readily produced. Adsorption behavior of C1/CO2 indicates that CO2 can help the C1 recovery from nanopores; meanwhile, the recovery efficiency in the larger pore, (i.e., 3 nm), is much higher than that in the smaller pore (i.e., 1 nm). On the contrary, as pressure decreases, adsorption of nC4 in nC4/CO2 mixtures in both nanopores is becoming stronger with the presence of CO2; the same behavior is also observed for C1/nC4/CO2 mixture. This implies that, although CO2 injection may help the recovery of lighter hydrocarbons (e.g., C1), but may not be an efficient agent for the recovery of heavier hydrocarbons (e.g., nC4).

Liu, Z., Portero, E.P., Jian, Y., Zhao, Y., Onjiko, R.M., Zeng, C., Nemes, P., 2019. Trace, machine learning of signal images for trace-sensitive mass spectrometry: A case study from single-cell metabolomics. Analytical Chemistry 91, 5768-5776.


Recent developments in high-resolution mass spectrometry (HRMS) technology enabled ultrasensitive detection of proteins, peptides, and metabolites in limited amounts of samples, even single cells. However, extraction of trace-abundance signals from complex data sets (m/z value, separation time, signal abundance) that result from ultrasensitive studies requires improved data

processing algorithms. To bridge this gap, we here developed “Trace”, a software framework that incorporates machine learning (ML) to automate feature selection and optimization for the extraction of trace-level signals from HRMS data. The method was validated using primary (raw) and manually curated data sets from single-cell metabolomic studies of the South African clawed frog (Xenopus laevis) embryo using capillary electrophoresis electrospray ionization HRMS. We demonstrated that Trace combines sensitivity, accuracy, and robustness with high data processing throughput to recognize signals, including those previously identified as metabolites in single-cell capillary electrophoresis HRMS measurements that we conducted over several months. These performance metrics combined with a compatibility with MS data in open-source (mzML) format make Trace an attractive software resource to facilitate data analysis for studies employing ultrasensitive high-resolution MS.

Losch, A., 2019. The need of an ethics of planetary sustainability. International Journal of Astrobiology 18, 259-266.

https://doi.org/10.1017/S1473550417000490

The concept of sustainability is widely acknowledged as a political guideline. Economic, ecological, social and cultural aspects of sustainability are already under discussion. Current space mining efforts demand that the discussion become a broader one about ‘planetary sustainability’, including the space surrounding Earth. To date, planetary sustainability has mainly been used with reference to Earth only and I will extend it here, elaborating on a similar NASA initiative. This article (1) sketches the contemporary economic–political initiatives which call for a special reflection of Earth's location in space, and then (2) discusses the meaning of the concept of sustainability in this context. Next, (3) I relate the discussion to the issue of planetary and environmental protection, before, (4) finally, presenting a philosophical and theological perspective that seems particularly able to broach the issue of the multiple dimensions of sustainability in this context. This is the concept of constructive-critical realism. My overview of the topic concludes with (5) a summarizing outlook.

Lu, A., Li, Y., Ding, H., Xu, X., Li, Y., Ren, G., Liang, J., Liu, Y., Hong, H., Chen, N., Chu, S., Liu, F., Li, Y., Wang, H., Ding, C., Wang, C., Lai, Y., Liu, J., Dick, J., Liu, K., Hochella Fr., M.F., 2019. Photoelectric conversion on Earth’s surface via widespread Fe- and Mn-mineral coatings. Proceedings of the National Academy of Sciences 116, 9741-9746.


Significance: In solar-terrestrial systems, solar energy input has long been recognized to have a profound impact on Earth. The well-known photosynthetic systems enable sustainable solar-to-chemical energy conversion. However, no evidence has yet emerged for the existence of a widespread geological light-harvesting system. This study reveals such a “photoelectric device,” where semiconducting Fe- and Mn (oxyhydr)oxide-mineral coatings are found to overlay vast expanses of natural rock/soil surfaces and exhibit highly responsive and stable photon-to-electron conversion. Our discovery may provide insight supporting vital photon-induced redox chemistry on Earth’s surface via widespread Fe- and Mn-mineral coatings.

Abstract: Sunlight drives photosynthesis and associated biological processes, and also influences inorganic processes that shape Earth’s climate and geochemistry. Bacterial solar-to-chemical energy conversion on this planet evolved to use an intricate intracellular process of phototrophy. However, a natural nonbiological counterpart to phototrophy has yet to be recognized. In this work, we reveal the inherent “phototrophic-like” behavior of vast expanses of natural rock/soil surfaces from deserts, red

soils, and karst environments, all of which can drive photon-to-electron conversions. Using scanning electron microscopy, transmission electron microscopy, micro-Raman spectroscopy, and X-ray absorption spectroscopy, Fe and Mn (oxyhydr)oxide-rich coatings were found in rock varnishes, as were Fe (oxyhydr)oxides on red soil surfaces and minute amounts of Mn oxides on karst rock surfaces. By directly fabricating a photoelectric detection device on the thin section of a rock varnish sample, we have recorded an in situ photocurrent micromapping of the coatings, which behave as highly sensitive and stable photoelectric systems. Additional measurements of red soil and powder separated from the outermost surface of karst rocks yielded photocurrents that are also sensitive to irradiation. The prominent solar-responsive capability of the phototrophic-like rocks/soils is ascribed to the semiconducting Fe- and Mn (oxyhydr)oxide-mineral coatings. The native semiconducting Fe/Mn-rich coatings may play a role similar, in part, to photosynthetic systems and thus provide a distinctive driving force for redox (bio)geochemistry on Earth’s surfaces.

Lu, J., Lin, R., Liu, C., Li, Y., Xiao, Z., He, Q., 2019. Genesis and origin of natural gas in the Beidagang structural belt of Dagang oilfield. Petroleum Science and Technology 37, 1501-1508.

https://doi.org/10.1080/10916466.2018.1511591

The south and north of Beidagang structure zone in Dagang oil field are Qikou sag and Banqiao sag respectively, it´s belong typical “two sag one uplift”, has abundant oil and gas source, developing reservoir condition is good. From now it has find various types of gas reservoirs in several heavy reservoirs and series of strata, so it has complex oil genesis and gas. This article collected a large number of natural gas samples systematically, launching a study on the composition and carbon isotope of natural gas, identifying the overall characteristics and causes of natural gas in Beidagang structure zone.Research shows in Beidagang structure zone, different heavy reservoirs and series of strata about composition and carbon isotope of natural gas are basically the same, methane contant is low, dry coefficient is small, spreading 0.8-0.89, belong typical wet gas. The distribution of methane and ethane carbon isotope are wide, insisting humic-type natural gas, sapropelic natural gas and biogas.Biogas are mainly distributed in Gangxi area, Banzhong, Bannan, Banbei, Tangjiahe, Baishuitou, Gangdong and Qianmiqiao area’s natural gas mainly is mainly the product of hydrocarbon source rock saprophytic organic matter mature stage in san-segment of Banqiao depression, Maxi ang Madong natural gas is the product of hydrocarbon source rock humus type organic matter mature stage of shahejie formation from Qikou depression. At present, the natural gas from the high over-maturity stage of the deep hydrocarbon source rocks in the depression is seldom distributed in the Beidagang structural belt, showing gas exploration in deep sag has a bright prospect.The high over mature stage natural gas in deep sag and Qikou depression Saproped-type hydrocarbon source rock crude oil cracking gas are important exploration target.

Lu, S., Li, J., Xue, H., Chen, F., Xu, Q., Wang, M., Li, W., Pang, X., 2019. Pyrolytic gaseous hydrocarbon generation and the kinetics of carbon isotope fractionation in representative model compounds with different chemical structures. Geochemistry, Geophysics, Geosystems 20, 1773-1793.

https://doi.org/10.1029/2018GC007722

Abstract: Five model compounds with representative chemical structures were selected for use in simulation experiments of pyrolytic gas production. The gas production and isotopic fractionation characteristics were observed and analyzed. Then, the factors affecting carbon isotope fractionation during natural gas generation were discussed, and a fractionation model was established and calibrated. We concluded that the final hydrocarbon gas (C1-5) yield of octadecane, octadecylamine,

octadecanoic acid, decahydronaphthalene, and 9-phenylanthracene decreased in turn with the effective hydrogen content. Compared with linear alkanes or alkyl compounds, cycloalkanes have higher thermal stability and generate gas later. The variation in the carbon isotopic composition of natural gas is primarily controlled by the following three factors: (a) the thermal evolution of organic matter results in a gradually heavier isotopic composition for the main gas production stage. (b) Gas inherits the isotopic composition of its parent material, and this effect is evident when the chemical structure and gas generation mechanism between parent materials are similar. (c) The structure of organic matter determines the reaction mechanism of gas generation, which has a significant influence on the range and trend of carbon isotope fractionation in the process of methane generation. An improved chemical kinetic model can accurately characterize carbon isotope fractionation during gas generation.

Lu, Y., Huang, C., Jiang, S., Zhang, J., Lu, Y., Liu, Y., 2019. Cyclic late Katian through Hirnantian glacioeustasy and its control of the development of the organic-rich Wufeng and Longmaxi shales, South China. Palaeogeography, Palaeoclimatology, Palaeoecology 526, 96-109.


Deposition of the organic-rich shales of the Wufeng and lowermost Longmaxi formations (late Katian through Hirnantian) occurred in a relatively stable tectonic setting and commenced at approximately 4.5 Myr prior to the end-Ordovician glacial maximum. These organic-rich shales are important because they provide a continuous sedimentary record of high-frequency eustatic changes associated with ice-sheet expansion and shrinkage. Here, we carried out a high-resolution cyclostratigraphic study of Fe3+ series and associated geochemical analysis of the Wufeng and lowermost Longmaxi shales in order to better understand sea-level cyclicity in the late Katian through Hirnantian ocean. The organic-rich shales deposited during this interval in the EHD1 drill core (Yichang, China) record four major Myr-scale eustatic cycles, which were associated with third-order sea-level fluctuations. Within each of these major cycles, 3–4 minor eustatic cycles corresponding to 405-kyr long eccentricity astronomical cycles were recognized and representing fourth-order eustatic changes. The cyclostratigraphic age of this study is generally in agreement with the radiometric dates in GTS2012, although the duration of the Hirnantian stage is ~0.5 Myr longer than previously thought. This study also infers glacial controls on the depositional environment of the organic-rich shales, as enhanced cooling triggered ice-sheet expansion and concurrent sea-level fall, leading to higher thermohaline circulation intensity and enhanced paleoproductivity through upwelling and terrestrial influx. In contrast, warming intervals led to ice-sheet shrinkage and concurrent deepening characterized by water column stratification and reduced nutrient supply. The results provide evidence in support of continuous continental glaciation in the late Katian through Hirnantian.

Lu, Z., Zhai, G., Zuo, Y., Wang, Q., Fan, D., Tang, S., Hu, D., Liu, H., Wang, T., Zhu, Y., Xiao, R., 2019. The geological process for gas hydrate formation in the Qilian Mountain permafrost. Petroleum Science and Technology 37, 1566-1581.

https://doi.org/10.1080/10916466.2019.1594283

The Qilian Mountain permafrost is the only place where gas hydrate occurs onshore China at present and its gas hydrate distribution is very complex and irregular. What patterns affecting the accumulation of gas hydrate or what process controlling the formation of gas hydrate are not clear in the study area. Aiming at a gas hydrate geological system, the geological process of gas hydrate formation was studied, based on geological data and analytical results obtained from drilling wells in the Qilian Mountain permafrost. As a result, three stages for the geological process of gas hydrate

formation are put forward in the study area. During the late Mid-Jurassic, the upper Triassic generated and provided a major gas source for gas hydrate, secondarily in combination with gas associated with oil generated from the middle Jurassic. The main gas source migrated upward via faults of F1 and F2, partly and occasionally mixed with the coal-bed methane and the microbial methane produced in the shallow strata. It was blocked jointly by thrust faults and thick mudstone or oil shale to be initially accumulated in gas reservoir. From Cretaceous to Pleistocene, the sedimentary strata experienced erosion and the initial gas accumulation turned into residual gas after series of the Qinghai-Tibet plateau uplift. Since the early middle Pleistocene, glaciations formed a gas hydrate stability zone (GHSZ) and the residual gas was coupled with GHSZ to form gas hydrate subsequently. Hence three patterns for the coupling of the residual gas with GHSZ are summarized in the study area. When the residual gas happened to lie within GHSZ, the residual gas directly formed gas hydrate, which was indicated by the drilling results that gas anomalies were encountered within GHSZ as well as occurrences of gas hydrate in the field. When the residual gas was below GHSZ, the residual gas would continually migrate into GHSZ to form gas hydrate, which was indicated by the drilling results that gas anomalies had ever been encountered even if below GHSZ as well as occurrences of gas hydrate within GHSZ in the field. When the residual gas was above GHSZ, the residual gas remained or escaped, which was indicated by the drilling results that gas anomalies even with a high pressure abnormity were encountered in the shallower strata above GHSZ without occurrences of gas hydrate within GHSZ in the field.

Luo, Q., Xiao, Z., Dong, C., Ye, X., Li, H., Zhang, Y., Ma, Y., Ma, L., Xu, Y., 2019. The geochemical characteristics and gas potential of the Longtan Formation in the eastern Sichuan Basin, China. Journal of Petroleum Science and Engineering 179, 1102-1113.


The Longtan Formation in the Sichuan Basin contains abundant organic-rich mudstones and coals, however, few studies have been conducted about their gas potential. A comprehensive study has been conducted on the Longtan sediments in order to determine their critical properties and gas potential. The Longtan samples, especially the coals, contain abundant organic matter, whereas S1 and S2 values are generally very low due to high thermal maturity. The organic component is dominated by the vitrinites, which comprises more than 95% of dispersed organic matter. The high vitrinite reflectance values (∼1.88–2.14% Ro) indicate a post thermal maturity of these sediments, which is consistent with the reliable Tmax values. The predominant mineral components are clay minerals and quartzs, and the brittle nature of the studied samples can be confirmed by the high contents of the brittle minerals and high brittleness indexes. The porosity positively correlates with total organic carbon (TOC), and abundant organic-matter, intraparticle, interparticle pores and fractures have been detected in these studied samples. The Longtan Formation in the study area was mainly deposited in an oxic environment. According to the 1D basin modelling, the Longtan sediments reached the maximum Ro after they have been buried to the maximum depth at late Cretaceous, and they began to generate gas at middle Jurassic. Attention shall be paid on the co-exploration and co-exploitation of shale gas and coalbed methane of the Longtan Formation of eastern Sichuan Basin in the future.

Lv, J.-H., Wei, X.-Y., Zhang, Y.-Y., Zong, Z.-M., 2019. Structural characterization of Baiyinhua lignite via direct and thermal decomposition methods. Fuel 253, 1042-1047.


Organic matter in Baiyinhua lignite (BL) was characterized by direct characterizations with solid-state 13C nuclear magnetic resonance spectrometer and X-ray photoelectron spectrometer, thermal

approaches with thermogravimetric analyzer, Curie-point pyrolyzer-gas chromatograph/mass spectrometer, and sequential thermal dissolution (TD) followed by the analysis with a gas chromatograph/mass spectrometer. The results show that normal alkanes, alkylnaphthalenes, and oxygen-containing organic compounds with Ar–O– and –(CO)–O– moieties are predominant in BL. Aliphatic carbon atoms are dominated by methylene with the average carbon number of 2. The number of aromatic rings (ARs) and substituents attached on the ARs are 2 and 4, respectively. The most abundant organic oxygen species contain Ar–O– moieties. The cleavage of >Cal-Cal<, >Car-Cal<, and >Car–O– bonds is the main reaction during the pyrolysis at 500 °C, which plays the most important role in devolatilizing organic species from BL. The products from the TD differ greatly due to the distinct pathways. When using methanol as the solvent, >C–O–C < bonds in BL can be broken easily, while the cleavage of –(C=O)–O– is negligible, which is the main reaction of TD in ethanol.

Lv, Y., Bai, H., Yang, J., He, Y., Ma, Q., 2019. Direct mass spectrometry analysis using in-capillary dicationic ionic liquid-based in situ dispersive liquid–liquid microextraction and sonic-spray ionization. Analytical Chemistry 91, 6661-6668.


The current study reports on a direct mass spectrometry (MS) analysis method using in-capillary dicationic ionic liquid (DIL)-based in situ dispersive liquid–liquid microextraction (DLLME) and sonic-spray ionization (SSI). The developed method merged extraction, enrichment, ionization, and detection of perfluorinated compounds (PFCs) in environmental water into a single step. A microliter-scale ternary fluidic system was designed and integrated into a disposable pulled capillary, in which an imidazolium-based germinal DIL reagent activated an in situ metathesis reaction. A penetrating slug-flow microextraction (SFME) process was subsequently initiated with significantly enhanced interfacial areas and mass transfer rates for the analytes of interest, the mechanism of which was revealed by simulations. An SSI assembly was in-house built, and it enabled a Venturi self-pumping using a stream of nitrogen gas flow coaxial to the capillary under atmospheric pressure to automatically spray at the tip of the capillary. The in situ formed DIL could bind with anionic PFC analytes to generate a positively charged complex, which benefits a signal increase of 1 to 2 orders in magnitude in the positive ion mode than in the negative ion mode for most analytes. The high sensitivity allowed the measure of sub-ppb (parts per billion) levels of PFCs in the environmental water samples. The developed method is a promising protocol for MS analysis because of unprecedented ease, significantly enhanced sensitivity, and potentially high sample throughput.



The presence of perchlorate on Mars suggests a possible energy source for sustaining microbial life. Perchlorate-reducing microbes have been isolated from perchlorate-contaminated soils and sediments on the Earth, but to date, never from an environment that is naturally enriched in perchlorate. The arid Pilot Valley paleolake basin in Utah is a Mars analog environment whose sediments are naturally enriched with up to ∼6.5 μg kg−1 perchlorate oxyanions. Here, we present results of field and laboratory studies indicating that perchlorate-reducing microorganisms co-occur with this potential electron acceptor. Biogeochemical data suggest ongoing perchlorate reduction; phylogenetic data indicate the presence of diverse microbial communities; and laboratory enrichments using Pilot Valley sediments show that resident microbes can reduce perchlorate. This is the first article of the

co-existence of perchlorate-reducing microbes in an environment where perchlorate occurs naturally, arguing for Pilot Valley's utility as an analog for studying biogeochemical processes that may have occurred, and may yet still be occurring, in ancient martian lacustrine sediments.

Ma, S., Tong, M., Yuan, S., Liu, H., 2019. Responses of the microbial community structure in Fe(II)-bearing sediments to oxygenation: The role of reactive oxygen species. ACS Earth and Space Chemistry 3, 738-747.


Responses of the microbial community structure in the subsurface to oxygen (O2) have been previously attributed to fundamental changes in microbial metabolic lifestyles. Here, we show that reactive oxygen species (ROS) produced from oxygenation of Fe(II)-bearing sediments play an important role in the variation of the microbial community structure. Sediments sampled along a vertical redox gradient were exposed to laboratory air. After a 10 h oxygenation, the living bacteria counts in sediments at the depth of 100 cm decreased from 6.1 to 5.7 orders of magnitude, 4.39 mg/g of Fe(II) was oxidized, and 27.6 μM hydroxyl radicals (•OH) was produced. Bacteria inactivation correlated well with •OH produced upon Fe(II) oxygenation. Control experiments with the addition of ROS quencher and hydrogen peroxide further proved that the bacteria inactivation was induced by ROS rather than O2. 16S rRNA analysis indicated that the relative abundance of Anaerolineaceae increased from 15.4 to 29.9% but that of Nistrospiraeceae and Geobacteraceae decreased, pointing to the suppression of nitrification, denitrification, and iron respiration but promotion of organic matter degradation. These findings reveal an important but overlooked mechanism for the influence of O2 on the microbial community structure.

Ma, X., Li, M., Pang, X., Wei, X., Qian, M., Tao, G., Liu, P., Jiang, Q., Li, Z., Zhao, Y., Wu, S., 2019. Paradox in bulk and molecular geochemical data and implications for hydrocarbon migration in the inter-salt lacustrine shale oil reservoir, Qianjiang Formation, Jianghan Basin, central China. International Journal of Coal Geology 209, 72-88.


This study analyzes the bulk and molecular geochemical data of 56 core samples of the Eocene Qianjiang Formation, a confined source rock unit embedded with salt intervals formed in a hypersaline lacustrine setting in central China. These source rocks within a single evaporative cycle collected from a recent shale oil exploration well are highly laminated, consisting of both intra- and inter-salt shales. Both organic pores and matrix pores serve as storage for hydrocarbon generated from kerogen within the source rock. Because the contrast in density between kerogen and oil, conversion of kerogen to oil inevitably leads to the increase in pore pressure and oil expulsion from kerogen within the same source rock unit. Impregnation of source rocks by expelled oils from nearby mature source rocks or from the organic-rich laminae within the same source rock units leads to anomalous Rock-Eval pyrolysis data, characterized by an abnormally high S1 peak, a high Production Index (PI), a suppressed Tmax and other anomalies. It is contradictory that both Rock-Eval pyrolysis data and sterane isomerization ratios of the studied inter-salt shale samples indicate strong impact of allochthonous hydrocarbons in the source rocks, whereas most aliphatic biomarker parameters obtained from the solvent extracts of these shales still provide useful information on the vertical variation in organic source input and depositional environment of the host rocks. This study provides insights into the bulk and molecular geochemical data interpretation, particularly in the inter-salt shale oil system evaluation in inferring the prevailing directions and pathways of diagenetic fluid movement and hydrocarbon migration.

Mackey, J.E., Stewart, B.W., 2019. Evidence of SPICE-related anoxia on the Laurentian passive margin: Paired δ13C and trace element chemostratigraphy of the upper Conasauga Group, Central Appalachian Basin. Palaeogeography, Palaeoclimatology, Palaeoecology 528, 160-174.


This study reports data from the Upper Cambrian Conasauga Group and overlying Copper Ridge Formation of the Central Appalachian region, eastern U.S.A. Geochemical, isotopic and petrographic analysis of core material was carried out to constrain the extent of marine anoxia and to characterize sediment fluxes on the carbonate platform and continental shelf of Laurentia contemporaneous with the Steptoean Positive Carbon Isotope Excursion (SPICE), a Late Cambrian global marine anoxic event. Carbonate rocks (primarily dolostone) record a positive δ13Ccarb excursion starting in the middle Nolichucky Formation, reaching its peak (+4.3‰) at the boundary between the Maynardville and Copper Ridge formations. Strontium isotope ratios in the dolostone units are only slightly offset from the expected Cambrian seawater values, suggesting minimal post-diagenetic disturbance of isotopic and trace element systematics. Selective leaching of carbonate units reveal upward decreasing trends in dissolved redox-sensitive trace metals (e.g., U, Ni, V) indicative of drawdown from regional and global marine anoxia during the peak of the Late Cambrian SPICE event.

Mahanipour, A., Mutterlose, J., Eftekhari, M., 2019. Calcareous nannofossils of the Barremian – Aptian interval from the southeastern Tethys (Zagros Basin, West Iran) and their paleoceanographic implications: A record of Oceanic Anoxic Event 1a. Marine Micropaleontology 149, 64-74.


Calcareous nannofossils and stable isotope data (δ13Ccarb) from a pelagic section of the Zagros Basin (west Iran) were used for an integrated oceanographic analysis of the Barremian – Aptian interval. The study aims at analyzing various oceanographic shifts recorded from this period, including the Oceanic Anoxic Event 1a (OAE 1a), in an expanded carbonate rich mudstone sequence of the eastern Tethys. The extreme thickness (510 m) of the succession allows us to study the environmental changes known from the Barremian and Aptian interval in much more detail than previously done. By looking at closely spaced samples it is possible to better understand the onset, the course and the aftermath of the OAE 1a event.

Calcareous nannofossils suggest an early Barremian (nannofossil zone CC5/NC5C) to late Aptian age (nannofossil zone CC7b/NC7B) for the studied sequence. The biostratigraphic zonation is based on the last occurrence of Calcicalathina oblongata, the first occurrences of Rucinolithus irregularis and Eprolithus floralis and the last occurrence of Micrantholithus hoschulzii. A total of 98 species has been encountered in the studied interval with good to moderate, in few cases poor preservation.

Based on the calcareous nannofossil assemblages, signals for a warming event in the mid-Barremian are characterized by high relative abundances of warm water specie (e.g., Rhagodiscus asper) along with neritic taxa (Micrantholithus spp., Nannoconus spp.) The OAE 1a was identified via calcareous nannofossil biostratigraphy in combination with the δ13Ccarb record. For the OAE 1a (early Aptian), warm and eutroph conditions were likely, as suggested by high relative abundances of R. asper, Diazomatolithus lehmanii, small Zeugrhabdotus spp. and Lithraphidites carniolensis. The late Aptian is characterized by cool surface water conditions.

Manda, Š., Štorch, P., Frýda, J., Slavík, L., Tasáryová, Z., 2019. The mid-Homerian (Silurian) biotic crisis in offshore settings of the Prague Synform, Czech Republic: Integration of the graptolite fossil record with conodonts, shelly fauna and carbon isotope data. Palaeogeography, Palaeoclimatology, Palaeoecology 528, 14-34.


The middle Homerian biotic crisis resulted in the almost complete eradication of graptolites. The shale-dominated Kosov Quarry section, central Bohemia, preserves the most complete graptolite record across the crisis in peri-Gondwanan Europe. The pre-extinction graptolite assemblage of the upper lundgreni Biozone, composed of ten species vanished in three extinction phases recognized in an interval 1.6 m thick. The crisis commenced with the increasing dominance of generalist taxa and subsequent extinction of several abundant species including Cyrtograptus lundgreni. The second phase coincided with the extinctions of genera Cyrtograptus and Testograptus, whereas long-ranging, generalist monograptids prevailed before they became extinct as the crisis culminated in its third phase in the flemingii Biozone. The lower part of the overlying parvus Biozone contains only Pristiograptus parvus, which became abundant in the upper part of the biozone, together with incoming Gothograptus nassa. The recovery interval is marked by a moderate diversification of monograptids and retiolitids. The extinction did not affect the diversity of pelagic cephalopods although their abundance was reduced. A bivalve-dominated benthic fauna disappeared throughout the extinction interval and re-appeared not earlier than in the latest Homerian. It was temporarily replaced by a time-specific fauna of anachronistic trilobites and brachiopods. The extinction interval coincided with sea-level fall, indicated by limestone slump-beds in a generally shaly succession. The post-extinction interval corresponds with a lowstand systems tract with deposition of condensed shelly limestone and burrowed shale. A positive carbon isotope excursion started in the flemingii Biozone and δ13C values increased up to the lower parvus Biozone above which the plateau of the first peak started. The beginning of the graptolite extinction predated the early phase of the late Homerian carbon isotope excursion. The terminal phase of the extinction, nevertheless coincided with the onset of the carbon isotope excursion and change in benthic fauna.



The speciation of vanadyl (VO2+) porphyrins in crude oil (vanadyl petroporphyrins) is an area of ongoing interest in petroleomics. In this paper, we describe a method for the speciation of vanadyl porphyrins that uses electron nuclear double resonance (ENDOR), a high-resolution electron paramagnetic resonance (EPR) spectroscopic technique. We use 1H ENDOR to measure hyperfine couplings between ligand protons and the paramagnetic vanadyl ion as small as about 0.15 MHz. From the measured hyperfine couplings, we directly determine all vanadium–ligand proton distances up to 8 Å. This information differentiates porphyrin ligands by their ring substitution pattern and substituent nature. We demonstrate this using a series of vanadyl porphyrin model compounds. Additionally, we demonstrate that the composition of binary vanadyl porphyrins mixtures can be determined. The ability of ENDOR to differentiate types of ligand protons in vanadyl porphyrin mixtures provides a basis for analyzing more complex mixtures of vanadyl petroporphyrins.

Mateos, R., Vera-López, S., Saz, M., Díez-Pascual, A.M., San Andrés, M.P., 2019. Graphene/sepiolite mixtures as dispersive solid-phase extraction sorbents for the analysis of polycyclic aromatic

hydrocarbons in wastewater using surfactant aqueous solutions for desorption. Journal of Chromatography A 1596, 30-40.


Different graphene/sepiolite (G/Sep) solid mixtures have been prepared and tested as nanometric sorbents for the analysis of polycyclic aromatic hydrocarbons (PAHs) using dispersive solid phase extraction (dSPE) and aqueous solutions of surfactants as environmentally friendly agents for desorption. Quantification of the PAHs was carried out by reversed-phase liquid chromatography (RP-HPLC) with fluorescence detection. The adsorption of four PAHs with increasing number of benzene rings into a G/Sep mixture (2/98, w/w) was investigated. A 100% retention was attained for phenanthrene (Phe), pyrene (Pyr) and benzo(a)pyrene (BaP), while for naphthalene (Nap) the maximum retention was close to 75%. The G/Sep mixtures can be used to remove the PAHs from wastewater. The desorption step was carried out using an aqueous surfactant solution: 100 mM non-ionic polyoxiethylen-23-lauryl eter (Brij L23). Considering the whole extraction process, the highest PAH recoveries (50, 92, 83 and 76% for Nap, Phe, Pyr and BaP, respectively) were obtained using 100 mM Brij L23. The developed method shows very high sensitivity, robustness and precision, as well as low limits of detection and quantification, and has been successfully applied to the analysis of PAHs in wastewater samples.

McArthur, J.M., 2019. Early Toarcian black shales: A response to an oceanic anoxic event or anoxia in marginal basins? Chemical Geology 522, 71-83.


The Early Toarcian, organic-rich, black shales of the Cleveland Basin, Yorkshire UK, are the type sediments for the supposed early Toarcian oceanic anoxic event. The sediments have values of Cd/Mo that are <0.1 and values of Co (mg/kg) × Mn (%) that are >0.4. These values are typical of sediment deposited in modern basins that are hydrographically restricted and show that the Cleveland Basin was hydrographically restricted when depositing organic-rich sediments. These palaeo-proxies confirm earlier interpretations, based on Mo/TOC values, that argued for hydrographic restriction. The term Toarcian oceanic anoxic event can now be discarded.



Applicability of thermophilic and thermo-tolerant microorganisms for biodegradation of polycyclic aromatic hydrocarbons (PAHs) with low water solubility is an interesting strategy for improving the biodegradation efficiency. In this study, we evaluated utility of thermophilic and thermo-tolerant bacteria isolated from Unkeshwar hot spring (India) for biodegradation of four different PAHs. Water samples were enriched in mineral salt medium (MSM) containing a mixture of four PAHs compounds (anthracene: ANT, fluorene: FLU, phenanthrene: PHE and pyrene: PYR) at 37 °C and 50 °C. After growth based screening, four potent strains obtained which were identified as Aeribacillus pallidus (UCPS2), Bacillus axarquiensis (UCPD1), Bacillus siamensis (GHP76) and Bacillus subtilis subsp. inaquosorum (U277) based on the 16S rRNA gene sequence analysis. Degradation of mixed PAH compounds was evaluated by pure as well as mixed cultures under shake flask conditions using MSM supplemented with 200 mg/L concentration of PAHs (50 mg/L of each compound) for 15 days at

37 °C and 50 °C. A relatively higher degradation of ANT (92%- 96%), FLU (83% - 86%), PHE (16% - 54%) and PYR (51% - 71%) was achieved at 50 °C by Aeribacillus sp. (UCPS2) and mixed culture. Furthermore, crude oil was used as a substrate to study the degradation of same PAHs using these organisms which also revealed with similar results with the higher degradation at 50 °C. Interestingly, PAH-degrading strains were also positive for biosurfactant production. Biosurfactants were identified as the variants of surfactins (lipopeptide biosurfactants) based on analytical tools and phylogenetic analysis of the surfactin genes. Overall, this study has shown that hot spring microbes may have a potential for PAHs degradation and also biosurfactant production at a higher temperature, which could provide a novel perspective for removal of PAHs residues from oil contaminated sites.

Menotti, T., Scheirer, A.H., Meisling, K., Graham, S.A., 2019. Integrating strike-slip tectonism with three-dimensional basin and petroleum system analysis of the Salinas Basin, California. American Association of Petroleum Geologist Bulletin 103, 1443-1472.

http://archives.datapages.com/data/bulletns/2019/06jun/BLTN17276/bltn17276.html

The Salinas Basin is a strike-slip basin in central California with stratigraphy dominantly composed of Miocene Monterey Formation. Despite a long history of oil production, aspects of petroleum system development in the basin remain poorly understood. Of the seven main oil fields, one—San Ardo field—has produced more than 500 million bbl of oil or 99% of all oil found in the basin. The evolution of this basin was profoundly influenced by strike-slip movement on the Rinconada Fault, which bisected the depocenter beginning circa 15 Ma. To address the influence of strike-slip motion on petroleum system development, we constructed a three-dimensional (3-D) basin and petroleum system model that incorporates strike-slip displacement. Seismic reflection profiles from a 3-D survey reveal four main tectonic stages that correspond to events in petroleum system evolution. Petroleum generation from type II kerogen source rock began circa 11 Ma, approximately 4 m.y. after strike-slip faulting began to offset a once-contiguous sedimentary depocenter. Two separate petroleum provinces—an eastern one and a western one—developed, and the fault zone likely was a conduit for petroleum, if nonsealing. Most accumulated petroleum was derived from the eastern pod of active source rock because of greater sedimentary burial east of the fault. Our model roughly replicates the skewed distribution in oil-field size. Factors controlling field size distribution include trap size and connectivity to source.

Metarapi, D., Šala, M., Vogel-Mikuš, K., Šelih, V.S., van Elteren, J.T., 2019. Nanoparticle analysis in biomaterials using laser ablation−single particle−inductively coupled plasma mass spectrometry. Analytical Chemistry 91, 6200-6205.


In the past decade, the development of single particle–inductively coupled plasma mass spectrometry (SP-ICPMS) has revolutionized the field of nanometallomics. Besides differentiation between dissolved and particulate metal signals, SP-ICPMS can quantify the nanoparticle (NP) number concentration and size. Because SP-ICPMS is limited to characterization of NPs in solution, we show how solid sampling by laser ablation (LA) adds spatial-resolution characteristics for localized NP analysis in biomaterials. Using custom-made gelatin standards doped with dissolved gold and commercial or synthesized gold nanoparticles, LA-SP-ICPMS conditions such as laser fluence, beam size, and dwell time were optimized for NP analysis to minimize NP degradation, peak overlap, and interferences from dissolved gold. A data-processing algorithm to retrieve the NP number concentration and size was developed for this purpose. As a proof-of-concept, a sunflower-root-

sample cross-section, originating from a sunflower plant exposed to gold NPs, was successfully imaged using the optimized LA-SP-ICPMS conditions for localized NP characterization.

Metcalfe, J.Z., Mead, J.I., 2019. Do uncharred plants preserve original carbon and nitrogen isotope compositions? Journal of Archaeological Method and Theory 26, 844-872.

https://doi.org/10.1007/s10816-018-9390-2

The isotopic compositions of plants can provide significant insights into paleodiets, ancient agricultural activities, and past environments. Isotopic compositions of charred (aka carbonized) ancient plant remains are typically preferred over those of uncharred/uncarbonized plants, both because charred plants are more commonly preserved and because early research suggested they experience less post-depositional isotopic alteration. In this paper, we re-explore the question of whether uncharred plants experience large-magnitude post-depositional changes in carbon and nitrogen isotope compositions by analyzing Terminal Pleistocene–Early Holocene plant specimens from rockshelters in the Escalante River Basin (Colorado Plateau, southeastern Utah). Several lines of evidence, including C3-CAM differences, plant-part comparisons, and dietary estimates from ancient herbivore collagen, suggest that the original carbon isotope compositions of these plants have not been significantly altered. The preservation status of plant nitrogen isotope compositions is equivocal. The direction of temporal shifts in plant δ15N matches global trends and the magnitude of the shift may have been exacerbated by the extinction of megafauna in an arid environment. However, the Pleistocene plant δ15N values are higher than would be expected based on herbivore bone collagen δ15N. Nevertheless, in contrast to previous research, the ancient uncharred plants in this study did not have exceptionally high δ15N values (> + 25‰). Overall, our research suggests that uncharred plants could be useful substrates for isotopic paleodietary and/or paleoenvironmental studies.

Meyer-Dombard, D.A.R., Osburn, M.R., Cardace, D., Arcilla, C.A., 2019. The effect of a tropical climate on available nutrient resources to springs in ophiolite-hosted, deep biosphere ecosystems in the Philippines. Frontiers in Microbiology 10, 761. doi: 10.3389/fmicb.2019.00761.


Springs hosted in ophiolites are often affected by serpentinization processes. The characteristically low DIC and high CH4 and H2 gas concentrations of serpentinizing ecosystems have led to interest in hydrogen based metabolisms in these subsurface biomes. However, a true subsurface signature can be difficult to identify in surface expressions such as serpentinizing springs. Here, we explore carbon and nitrogen resources in serpentinization impacted springs in the tropical climate of the Zambales and Palawan ophiolites in the Philippines, with a focus on surface vs. subsurface processes and exogenous vs. endogenous nutrient input. Isotopic signatures in spring fluids, biomass, and carbonates were examined to identify sources and sinks of carbon and nitrogen, carbonate geochemistry, and the effect of seasonal precipitation. Seasonality affected biomass production in both low flow and high flow spring systems. Changes in meteorological precipitation affected δ13CDIC and δ13CDOC values of the spring fluids, which reflected seasonal gain/loss of atmospheric influence and changes in exogenous DOC input. The primary carbon source in high flow systems was variable, with DOC contributing to biomass in many springs, and a mix of DIC and carbonates contributing to biomass in select locations. However, primary carbon resources in low flow systems may depend more on endogenous than exogenous carbon, even in high precipitation seasons. Isotopic evidence for nitrogen fixation was identified, with seasonal influence only seen in low flow systems. Carbonate formation was found to occur as a mixture of recrystallization/recycling of older carbonates and rapid mineral precipitation (depending on the system), with highly δ13C and δ18O

depleted carbonates occurring in many locations. Subsurface signatures (e.g., low DOC influence on Cbiomass) were most apparent in the driest seasons and lowest flow systems, indicating locations where metabolic processes divorced from surface influences (including hydrogen based metabolisms) are most likely to be occurring.


https://doi.org/10.1029/2018JE005796

Abstract: McLaughlin crater is a 92-km diameter complex crater that formed on Mars ~4 billion years ago. The resulting basin was the site of a large (~3,000 km2), deep (~500 m), voluminous (~1,500 km3) Martian lake circa 3.8 Ga. While there is strong evidence that hundreds of lakes have existed on Mars at some point during the same time period, the geology of McLaughlin crater is extraordinary for a number of reasons. Detailed spectral analyses show that the deep-water sediments include detrital inputs of olivine and pyroxene, but the lake-floor sediments include lithologies with abundant Fe-rich, Mg-bearing smectite, serpentine-rich deposits, and ferrihydrite. For astrobiologists, this site provides a treasure trove of high-priority targets. Serpentinization reactions are thought to have played a key role in abiogenesis on Earth, and within McLaughlin crater, deposits of subterranean and probably sublacustrine serpentinites are well preserved. In addition, delta sequences are well exposed throughout the east side of the basin; such deposits are endorsed by some as the highest priority targets for preservation of organics on Mars. Yet deep-water turbidites, which might have flowed through hydrothermal environments, may be the most intriguing aspect of this geology. Such rapid sedimentation could have sequestered and preserved any potential organic materials for future exploration by a rover.

Plain Language Summary: Though Mars is cold, dry, and inhospitable today, it contains evidence for many dry lake beds—relics of an ancient climate that was at least episodically warmer and wetter. Considering that lakes can be an excellent environments for life on Earth, a common thread of Mars research has been to characterize the environmental conditions under which Martian lakes formed in order to better understand their implications for past habitability of the red planet. The goal of this work is to characterize the geology of McLaughlin crater, where a lake existed on Mars over 3.8 billion years ago. McLaughlin lake was vast, deep (~ 500 m), and probably long lived. Many characteristics of McLaughlin lake are unlike those seen in any other ancient lake basins on Mars. This lake contained a range of sedimentary environments including delta deposits, shallow‐water fan deposits, and deep‐water, fine‐grained materials. It is the only known place on Mars where fine‐grained, subaqueous “landslides” called turbidites are identified, and these are important because we know that such deposits can be sites of excellent preservation of organic matter on Earth (due to rapid burial).

Mijnendonckx, K., Miroslav, H., Wang, L., Jacops, E., Provoost, A., Mysara, M., Wouters, K., De Craen, M., Leys, N., 2019. An active microbial community in Boom Clay pore water collected from piezometers impedes validating predictive modelling of ongoing geochemical processes. Applied Geochemistry 106, 149-160.


Safe geological disposal of radioactive waste requires a detailed understanding of the geochemical conditions present in the host formation. Consequently, analysis of pore water is essential, as its

composition determines among others, the speciation and solubility of radionuclides. Boom Clay is considered a potential host formation in Belgium. Although the elemental composition of Boom Clay pore water is relatively well known, the real mechanisms controlling the pCO2 (g) and the pH, the two most important parameters, are not completely understood. Currently, these parameters are under investigation based only on inorganic chemistry. Borehole waters of different Underground Research Facilities (URF) harbour an active microbial community; however, their possible impact on the geochemistry of Boom Clay pore water extracted from piezometers is not yet examined. The present study discusses the evolution of the geochemistry and the microbial community in the pore water from the piezometers around the PRACLAY gallery of the HADES URF during 7 years after installation of the piezometers. Overall, the elemental composition seemed to vary during the first 4 years, while afterwards it remained quite stable. However, the pCO2 values varied substantially over time, while the pCH4 increased in all filters. The presence of an active microbial community in the piezometers, could explain why experimental pCO2 – pH data do not correspond to the data obtained by predictive modelling, hampering validation of current predictive models of the ongoing geochemical processes. Moreover, the nature of the sampling equipment and the sampling procedure possibly stimulated the present microbial community, resulting in increased methane production rates. To improve predictive modelling, microbial processes are needed to be taken into account together with inorganic geochemistry considered at the current stage, which necessitates detailed microbial and geochemical monitoring in future studies.



The kinetics of urea hydrolysis (ureolysis) and induced calcium carbonate (CaCO3) precipitation for engineering use in the subsurface was investigated under aerobic conditions using Sporosarcina pasteurii (ATCC strain 11859) as well as Bacillus sphaericus strains 21776 and 21787. All bacterial strains showed ureolytic activity inducing CaCO3 precipitation aerobically. Rate constants not normalized to biomass demonstrated slightly higher-rate coefficients for both ureolysis (kurea) and CaCO3 precipitation (kprecip) for B. sphaericus 21776 (kurea =0.10±0.03 h−1, kprecip =0.60±0.34 h−1) compared to S. pasteurii (kurea =0.07±0.02h−1, kprecip =0.25±0.02 h−1), though these differences were not statistically significantly different. B. sphaericus 21787 showed little ureolytic activity but was still capable of inducing some CaCO3 precipitation. Cell growth appeared to be inhibited during the period of CaCO3 precipitation. Transmission electron microscopy (TEM) images suggest this is due to the encasement of cells and was reflected in lower kurea values observed in the presence of dissolved Ca. However, biomass regrowth could be observed after CaCO3 precipitation ceased, which suggests that ureolysis-induced CaCO3 precipitation is not necessarily lethal for the entire population. The kinetics of ureolysis and CaCO3 precipitation with S. pasteurii was further analyzed under anaerobic conditions. Rate coefficients obtained in anaerobic environments were comparable to those under aerobic conditions; however, no cell growth was observed under anaerobic conditions with NO3

−, SO4

2− or Fe3+ as potential terminal electron acceptors. These data suggest that the initial rates of ureolysis and ureolysis-induced CaCO3 precipitation are not significantly affected by the absence of oxygen but that long-term ureolytic activity might require the addition of suitable electron acceptors. Variations in the ureolytic capabilities and associated rates of CaCO3 precipitation between strains must be fully considered in subsurface engineering strategies that utilize microbial amendments.

Mitchell, R.L., Strullu-Derrien, C., Kenrick, P., 2019. Biologically mediated weathering in modern cryptogamic ground covers and the early Paleozoic fossil record. Journal of the Geological Society 176, 430-439.


Specific micro-weathering features and biochemically derived residues formed by living organisms can be used as biomarkers to infer the presence of biological communities within sedimentary units of ancient ecosystems. We examined basaltic soil minerals from modern cryptogamic ground covers (CGCs) in Iceland and compared these with two early Paleozoic fossil systems. Nine biologically mediated weathering features (BWFs) were identified in modern soils including micron-scale surface trenching and penetrative tunnels, which are attributed to the actions of bacteria, fungi and exudates. Specific BWFs are associated with Fe residues, and with Fe-rich bio-precipitated nodules. Further, putative comparable features and Fe enrichment are identified in palaeosols from the late Silurian (Llansteffan, south Wales) and the Early Devonian (Rhynie chert, Scotland). Although we are cautious about attributing biological affinity to individual isolated features, our results demonstrate the potential of using multiple BWF types as a collective together with their chemical signatures as new proxies to understand community structure and interactions in early terrestrial ecosystems. This new information is the first evidence of interactions between ancient CGC-like organisms and substrate or soil inorganic components in the fossil record, and demonstrates the ability of CGC-like biospheres to contribute to mineral weathering, soil development and biogeochemical cycling during the early Paleozoic.Supplementary material: Fieldwork geomorphological information and triplot SEM-EDS data are available at https://doi.org/10.6084/m9.figshare.c.4373717

Mitzscherling, J., Horn, F., Winterfeld, M., Mahler, L., Kallmeyer, J., Overduin, P.P., Schirrmeister, L., Winkel, M., Grigoriev, M.N., Wagner, D., Liebner, S., 2019. Microbial community composition and abundance after millennia of submarine permafrost warming. Biogeosciences Discussions 2019, 1-29.


Warming of the Arctic led to an increase of permafrost temperatures by about 0.3 °C during the last decade. Permafrost warming is associated with increasing sediment water content, permeability and diffusivity and could on the long-term alter microbial community composition and abundance even before permafrost thaws. We studied the long-term effect (up to 2500 years) of submarine permafrost warming on microbial communities along an onshore-offshore transect on the Siberian Arctic Shelf displaying a natural temperature gradient of more than 10 °C. We analysed the in-situ development of bacterial abundance and community composition through total cell counts (TCC), quantitative PCR of bacterial gene abundance and amplicon sequencing, and correlated the microbial community data with temperature, pore water chemistry and sediment physicochemical parameters. On time-scales of centuries, permafrost warming coincided with an overall decreasing microbial abundance while millennia after warming microbial abundance was similar to cold onshore permafrost and DOC content was least. Based on correlation analysis TCC unlike bacterial gene abundance showed a significant rank-based negative correlation with increasing temperature while both TCC and bacterial gene copy numbers showed a negative correlation with salinity. Bacterial community composition correlated only weakly with temperature but strongly with pore-water stable isotope signatures and depth, while it showed no correlation with salinity. Microbial community composition showed substantial spatial variation and an overall dominance of Actinobacteria, Chloroflexi, Firmicutes, Gemmatimonadetes and Proteobacteria which are amongst the microbial taxa that were found to be active in other frozen permafrost environments as well. We suggest that, millennia after permafrost warming by over 10 °C, microbial community composition and abundance show some indications for

proliferation but mainly reflect the sedimentation history and paleo-environment and not a direct effect through warming.

Miyazaki, Y., Gowda, D., Tachibana, E., Takahashi, Y., Hiura, T., 2019. Identification of secondary fatty alcohols in atmospheric aerosols in temperate forests. Biogeosciences 16, 2181-2188.


Fatty alcohols (FAs) are major components of surface lipids (waxes) and can act as surface-active organic aerosols in the atmosphere, influencing chemical reactions, particle lifetimes, and the formation of cloud droplets and ice nuclei. However, studies on the composition and source of the FAs in atmospheric aerosols are very limited. In this study, we identified five secondary FAs (SFAs) with C27 and C29 from aerosol samples collected throughout 1 year at two different deciduous forest sites in Japan. Fatty diols, such as n-heptacosan-5,10-diol, were identified in atmospheric aerosols for the first time. Among the identified SFAs, n-nonacosan-10-ol was the most abundant compound, followed by n-nonacosan-5-10-diol at both of the forest sites. Concentrations of the SFAs exhibited distinct seasonal variation, with pronounced peaks during the growing season at each forest site. The SFAs showed significant correlation with sucrose, which is used as a molecular tracer of pollen. A significant fraction of the SFAs was attributed to the submicrometer particles in the growing season. The results indicate that they originated mostly from plant waxes and could be used as useful tracers for primary biological aerosol particles.

Molteni, U., Simon, M., Heinritzi, M., Hoyle, C.R., Bernhammer, A.-K., Bianchi, F., Breitenlechner, M., Brilke, S., Dias, A., Duplissy, J., Frege, C., Gordon, H., Heyn, C., Jokinen, T., Kürten, A., Lehtipalo, K., Makhmutov, V., Petäjä, T., Pieber, S.M., Praplan, A.P., Schobesberger, S., Steiner, G., Stozhkov, Y., Tomé, A., Tröstl, J., Wagner, A.C., Wagner, R., Williamson, C., Yan, C., Baltensperger, U., Curtius, J., Donahue, N.M., Hansel, A., Kirkby, J., Kulmala, M., Worsnop, D.R., Dommen, J., 2019. Formation of highly oxygenated organic molecules from α-pinene ozonolysis: Chemical characteristics, mechanism, and kinetic model development. ACS Earth and Space Chemistry 3, 873-883.


Terpenes are emitted by vegetation, and their oxidation in the atmosphere is an important source of secondary organic aerosol (SOA). A part of this oxidation can proceed through an autoxidation process, yielding highly oxygenated organic molecules (HOMs) with low saturation vapor pressure. They can therefore contribute, even in the absence of sulfuric acid, to new particle formation (NPF). The understanding of the autoxidation mechanism and its kinetics is still far from complete. Here, we present a mechanistic and kinetic analysis of mass spectrometry data from α-pinene (AP) ozonolysis experiments performed during the CLOUD 8 campaign at CERN. We grouped HOMs in classes according to their identified chemical composition and investigated the relative changes of these groups and their components as a function of the reagent concentration. We determined reaction rate constants for the different HOM peroxy radical reaction pathways. The accretion reaction between HOM peroxy radicals was found to be extremely fast. We developed a pseudo-mechanism for HOM formation and added it to the AP oxidation scheme of the Master Chemical Mechanism (MCM). With this extended model, the observed concentrations and trends in HOM formation were successfully simulated.

Monachon, M., Albelda-Berenguer, M., Joseph, E., 2019. Biological oxidation of iron sulfides. Advances in Applied Microbiology 107, 1-27.


The biological oxidation of minerals and ores, called bioleaching, has been studied for the last decades to solubilize metals and recover them. In particular, iron sulfides are the most studied ores for an optimum extraction of different metals, such as copper or zinc. The use of chemolithotrophic bacteria, as Acidothiobacillus ferrooxidans, to oxidize both iron and sulfur species in aerobic conditions and at acidic pH shows promising results. In the field of heritage preservation, the development of “green” treatments is more and more studied. Waterlogged archeological wood presents an accumulation of iron sulfides within its structure, which, after exposition to oxygen, lead to salt precipitation and acidification and so to the degradation of the wooden artifact. A new extraction method, based on the dissolution of iron sulfides by the use of bacteria could be an alternative to the current chemical extraction methods, as being more respectful and ecological. While A. ferrooxidans is very effective in mines and groundwater, in the field of conservation-restoration of wood, Thiobacillus denitrificans is a better candidate as it grows at neutral pH, which is less aggressive for organic substrates (wood here). Preliminary studies show the efficiency of T. denitrificans for the dissolution of iron sulfides, as the concentration of nitrates used as electron donors decreases while the concentration of sulfates produced increases without degrading the wooden matrix. Long-term behavior should be studied to assess the stability of the artifacts after treatment.

Moores, J.E., Gough, R.V., Martinez, G.M., Meslin, P.-Y., Smith, C.L., Atreya, S.K., Mahaffy, P.R., Newman, C.E., Webster, C.R., 2019. Methane seasonal cycle at Gale Crater on Mars consistent with regolith adsorption and diffusion. Nature Geoscience 12, 321-325.

https://doi.org/10.1038/s41561-019-0313-y

A strong, repeatable seasonal cycle in the background methane mixing ratio has been observed at the Gale Crater landing site of the Mars Science Laboratory rover with the Tunable Laser Spectrometer of the Sample Analysis at Mars instrument. However, as of yet, no physical process has been proposed that can explain both the timing and amplitude of the observations. Here we show that a one-dimensional numerical model considering adsorption onto and diffusion through the regolith can reproduce the variation, including a phase lag, if the regolith is impregnated with methane from a prior plume or supplied from below by microseepage. Combining the model results with geological constraints, we estimate that the amount of microseepage at Gale is at most 3 × 10−5 tonnes km−2 yr−1. Gale’s unique dynamical environment makes such seeps easier to detect in surface sampling measurements. Over most of the Martian surface, atmospheric mixing is stronger or atmospheric transport more effective, and we expect the amplitude of the seasonal cycle to be smaller for the same strength of seep.

Morad, D., Nader, F.H., Morad, S., Rossi, C., Gasparrini, M., Alsuwaidi, M., Al Darmaki, F., Hellevang, H., 2019. Limited thermochemical sulfate reduction in hot, anhydritic, sour gas carbonate reservoirs: The Upper Jurassic Arab Formation, United Arab Emirates. Marine and Petroleum Geology 106, 30-41.


Limited thermochemical sulfate reduction (TSR) in hot (130–160°C) and anhydrite-rich sour gas reservoir carbonates of the Arab Formation (Upper Jurassic) is manifested by rare calcitization of anhydrite with slightly lower δ13CVPDB values (−3.2 to −0.1‰) than calcite precipitated in equilibrium with Late Jurassic seawater. Fluid inclusion microthermometry of calcite that has replaced anhydrite indicates that TSR occurred between 130°C and 160°C. The lack of evidence for extensive TSR, despite the suitable current temperatures and abundant sulfates in the gas reservoir, coupled with the relatively more common TSR-related calcite in the flanks (water zone) than crest (gas zone), indicate that: (1) gas emplacement while the reservoir was buried at shallower depth slowed down or inhibited TSR in the crest even when it subsequently reached depths where extensive TSR would occur, and (2) H2S (up to 38 vol%) has migrated from the underlying Permo-Triassic and/or Jurassic sulfate-carbonate deposits. This study demonstrates that constraining the timing of hydrocarbon emplacement within the context of burial-thermal history is crucial for a better understanding of the origin and distribution of H2S in hot, anhydrite-rich, sour gas reservoirs.

Moridis, G.J., Queiruga, A.F., Reagan, M.T., 2019. Simulation of gas production from multilayered hydrate-bearing media with fully coupled flow, thermal, chemical and geomechanical processes using TOUGH + Millstone. Part 1: Numerical modeling of hydrates. Transport in Porous Media 128, 405-430.

https://doi.org/10.1007/s11242-019-01254-6

TOUGH + Millstone has been developed for the analysis of coupled flow, thermal and geomechanical processes associated with the formation and/or dissociation of CH4-hydrates in geological media. It is composed of two constituent codes: (a) a significantly enhanced version of the TOUGH + HYDRATE simulator, V2.0, that accounts for all known flow, physical, thermodynamic and chemical processes associated with the behavior of hydrate-bearing systems undergoing changes and includes the most recent advances in the description of the system properties, coupled seamlessly with (b) Millstone V1.0, a new code that addresses the conceptual, computational and mathematical shortcomings of earlier codes used to describe the geomechanical response of these systems. The capabilities of TOUGH + Millstone are demonstrated in the simulation and analysis of the system flow, thermal and geomechanical behavior during gas production from a realistic complex offshore hydrate deposit. In the first paper of this series, we discuss the physics underlying the T + H hydrate simulator, the constitutive relationships describing the physical, chemical (equilibrium and kinetic) and thermal processes, the states of the CH4+H2O system and the sources of critically important data, as well as the mathematical approaches used for the development of the of mass and energy balance equations and their solution. Additionally, we provide verification examples of the hydrate code against numerical results from the simulation of laboratory and field experiments.

Muchowska, K.B., Varma, S.J., Moran, J., 2019. Synthesis and breakdown of universal metabolic precursors promoted by iron. Nature 569, 104-107.

https://doi.org/10.1038/s41586-019-1151-1

Life builds its molecules from carbon dioxide (CO2) and breaks them back down again through the intermediacy of just five metabolites, which are the universal hubs of biochemistry. However, it is unclear how core biological metabolism began and why it uses the intermediates, reactions and pathways that it does. Here we describe a purely chemical reaction network promoted by ferrous iron, in which aqueous pyruvate and glyoxylate—two products of abiotic CO2 reduction—build up 9 of the 11 intermediates of the biological Krebs (or tricarboxylic acid) cycle, including all 5 universal metabolic precursors. The intermediates simultaneously break down to CO2 in a life-like regime that

resembles biological anabolism and catabolism5. Adding hydroxylamine and metallic iron into the system produces four biological amino acids in a manner that parallels biosynthesis. The observed network overlaps substantially with the Krebs and glyoxylate cycles, and may represent a prebiotic precursor to these core metabolic pathways.

Mukherjee, R., Muduli, P.R., Barik, S.K., Kumar, S., 2019. Sources and transformations of organic matter in sediments of Asia’s largest brackish water lagoon (Chilika, India) and nearby mangrove ecosystem. Environmental Earth Sciences 78, 332.

https://doi.org/10.1007/s12665-019-8329-6

The present study aimed to understand sources and transformations of organic matter along with cycling of nitrogen and carbon in sediments of two geographically close but ecologically distinct wetlands located on the east coast of India viz. Chilika lagoon (Asia’s largest brackish water lagoon) and Bhitarkanika mangrove. The study also investigates potential nitrogen loss pathways in the bottom sediments and explores stables isotopes as a proxy for the source identification of sediment organic matter in shallow aquatic ecosystems. For this purpose, the isotopic compositions of organic carbon and nitrogen (δ13Corg and δ15N) and its contents (% Corg and % N) were measured at different depths in sediment cores collected from the Chilika lagoon (eight cores) and Bhitarkanika mangrove forest (three cores). Overall, the mean δ13Corg and % Corg in the lagoon were − 21.10 ± 0.79‰ and 0.84 ± 0.47%, respectively; whereas the same for mangrove cores were − 24.56 ± 0.80‰ and 1.04 ± 0.26%, respectively. Similarly, average δ15N and % N in the lagoon cores were 4.15 ± 0.63‰ and 0.11 ± 0.05%, respectively; for mangrove cores, the values were 4.28 ± 0.50‰ and 0.07 ± 0.01%, respectively. Isotopic composition and elemental ratios indicated organic matter in the sediments of Bhitarkanika mangrove to be a mixture of terrigenous and marine origin with relative dominance of terrestrial influence. A significant increase in δ13Corg of sediment organic matter compared to suspended particulate organic matter in the Chilika indicated transformation of organic matter in the water or sediment column through mineralization and diagenetic alterations. The δ15N of sediment or particulate organic matter did not show clear evidence of nitrogen loss in the recent past in these two ecosystems through processes such as denitrification. The absence of a relationship between δ13Corg of particulate and sediment organic matter in the Chilika indicated lack of efficient exchange between suspended and sediment organic matter.



Molecular fossils (biomarkers) are abundant in organic rich natural archives such as peats and lignites (fossilized peat), where their distribution is governed by their biological source, environmental factors, such as temperature and pH, and diagenetic reactions. As a result, biomarkers in peat have become an important tool to study past variations in vegetation, environment and climate in terrestrial settings, as well as biogeochemistry on time-scales of hundreds to millions of years ago. In recent years, significant progress has been made in understanding the controls on biomarker distributions, especially those derived from microorganisms and peat-forming plants, allowing for example, the quantification of past temperature and vegetation history during peat formation. Herein, we provide a review of a range of commonly applied biomarker proxies in peats, discuss the latest proxy developments, and explore the potential of using biomarkers in peat and lignite as

paleoenvironmental proxies. We provide a framework for biomarker analyses in peat and identify possible future research directions.

Naeher, S., Hollis, C.J., Clowes, C.D., Ventura, G.T., Shepherd, C.L., Crouch, E.M., Morgans, H.E.G., Bland, K.J., Strogen, D.P., Sykes, R., 2019. Depositional and organofacies influences on the petroleum potential of an unusual marine source rock: Waipawa Formation (Paleocene) in southern East Coast Basin, New Zealand. Marine and Petroleum Geology 104, 468-488.


The Paleocene Waipawa Formation is a widespread, ∼2–80 m-thick marine mudstone that occurs in several New Zealand basins. It is relatively enriched in organic matter (OM) and is the inferred source of a sub-commercial oil discovery and several correlated oil seeps. To determine the organofacies and depositional influences on the petroleum potential of the formation, we have undertaken a high-resolution, multidisciplinary study of the Taylor White section in the central East Coast Basin. This section is the thickest stratigraphically coherent surface exposure of the formation and includes contacts with the bounding Whangai and Wanstead formations. Bathymetric indicators within the foraminiferal assemblages indicate a slope setting for the section, deepening from middle to lower bathyal through the Waipawa–Wanstead succession. Significantly, the Whangai Formation in this section is barren of foraminifera. Dinoflagellate and calcareous nannofossil biostratigraphy provides somewhat conflicting age control but a resulting age model indicates a tenfold increase in compacted sediment accumulation rate during Waipawa deposition (from ∼1 to ∼10 cm/ky).

Our multivariate statistical analysis of geochemical and paleontological data reveals systematic variation in paleoenvironmental and source rock parameters within the section, with samples forming four distinct clusters or organofacies: OM-rich and OM-poor Waipawa organofacies, Whangai, and Wanstead organofacies. The two Waipawa organofacies are distinguished by enrichments in total organic carbon (TOC) and organic 13C, dominance of phytoclasts (mainly degraded woody plant matter; 66–98%), and low amounts of amorphous organic matter (<3%). Higher contributions of terrestrial OM are also indicated by high phenol/naphthalene ratios and higher plant biomarkers of mainly angiosperm origin (e.g., high relative oleanane contents, and high C24 tetracyclic/C23 tricyclic terpane ratio). A small but significant marine OM contribution within the Waipawa deposition is indicated by unusually high abundance of C30 steranes of marine pelagophyte origin, whereas the higher sulfur content and redox indicators signal hypoxic to anoxic conditions within the depositional environment. Stratigraphic fluctuations in key geochemical parameters within the Waipawa Formation indicate episodic influxes of terrestrial OM into the slope environment, with consequent reduction in water-column oxygen levels. The inferred oxygen depletion in the water column and sediments together with sulfurisation appears to have resulted in enhanced preservation of OM.

Whangai and Wanstead organofacies are characterised by a greater proportion of marine OM but are distinguished from each other by differences in OM preservation: OM is well-preserved with indications of hypoxia in the Whangai organofacies but is poorly preserved in the Wanstead organofacies. Geochemical fingerprinting identifies an interval of Whangai organofacies that separates two phases of Waipawa organofacies deposition. The lower phase comprises four alternations between OM-rich and OM-poor Waipawa organofacies and the upper phase comprises a single pulse of OM-rich Waipawa facies bounded by OM-poor intervals.

Overall, Waipawa Formation in this section has TOC and pyrolysable hydrocarbon (S2) values of 0.2–4.6 (mean 2.2) wt% and 0.1–12.4 (mean 3.9) mg HC/g rock, respectively. One-third of S2 values exceed 5 mg HC/g rock, indicating good‒very good bulk petroleum potential, with the remainder having poor‒fair potential. Petroleum potential (S2) increases with increasing TOC (R2 = 0.85).

Hydrogen index (HI) values range from 21 to 295 mg HC/g TOC, averaging just 147 mg HC/g TOC. In line with these modest HI values, quantitative pyrolysis-gas chromatography confirms that the petroleum potential is primarily for gas or gas-condensate, with relatively little oil potential. Of the total paraffinic petroleum yield, gas (n-C1–5) contributes 80–100%, whilst total (n-C6+) and non-volatile (n-C15+) paraffinic oil contribute ≤20% and ≤6%, respectively. Despite the low paraffinic oil potentials, n-C6+ and n-C15+ correlate relatively strongly with HI, and less strongly with TOC.

The overall gas-condensate-prone nature of the Waipawa organofacies at Taylor White reflects the predominance of woody phytoclasts, which are unlikely to produce paraffinic oil. The small paraffinic oil component is instead more likely to be associated with the marine algal component. Although this component is volumetrically subordinate, the higher paraffinic oil potential appears to result from the combination of high productivity of specific marine algae (i.e., pelagophytes), hypoxic depositional conditions and, most importantly, increased preservation of OM, including through sulfurisation. This raises the possibility of more algal-rich, oil-prone facies existing within the Waipawa Formation in areas with higher TOC or, alternatively, in areas beyond the direct reach of the terrestrial influxes, yet still sufficiently influenced by low water-column oxygen levels and high sulfur contents that promote enhanced OM preservation.

Nagappan, S., Devendran, S., Tsai, P.-C., Dinakaran, S., Dahms, H.-U., Ponnusamy, V.K., 2019. Passive cell disruption lipid extraction methods of microalgae for biofuel production – A review. Fuel 252, 699-709.


The conventional method of lipid extraction mandatorily includes cell lysis which is considered an essential process for the enhancement of extraction efficiency. However, cell lysis method especially those incorporating mechanical and physical methods such as homogenization, sonication, microwave techniques, etc., are energy intensive and drastically escalates the biofuel production cost. Therefore, the development of an alternate route of extraction skipping the conventional mechanical cell lysis step remains a challenge to be accomplished. In this context, we discuss the reports involving passive techniques that are able to extract lipid from microalgae without significant cell wall shearing. This includes methods such as in-situ transesterification, direct saponification, supercritical fluid extraction, organic solvent extraction, etc. Moreover, the review discusses the employment of passive lipid extraction methods in a biorefinery set-up, outlining the various bioproducts that could be generated along with lipid. The review concludes with the analysis of the economics of microalgal lipid extraction using passive disruption methods and compares with the processes incorporating cell lysis steps.

Nageswar Rao, M., Ram, A., Pradhan, U.K., Siddaiah, V., 2019. Factors controlling organic matter composition and trophic state in seven tropical estuaries along the west coast of India. Environmental Geochemistry and Health 41, 545-562.

https://doi.org/10.1007/s10653-018-0150-8

To understand the organic matter (OM) sources and trophic states, spatial and seasonal (post-monsoon and pre-monsoon) variation in sedimentary OM compositions was investigated in seven tropical estuaries of the state of Maharashtra along the central west coast of India. Based on the result of cluster analysis, estuaries were segregated into two distinct groups: Northern Maharashtra and Southern Maharashtra owing to dissimilarity in OM characteristics potentially constrained by geomorphology and catchment properties. Enrichment of Corg and major biochemical compounds

(lipids, carbohydrates and proteins) in the middle zone of most estuaries highlighted towards the addition of allochthonous OM. Results of principal component analysis highlighted the similar source of OM in most of the estuaries during both seasons and their distribution largely constrained by grain size change. The benthic trophic state indicated the prevalence of eutrophic state in the middle zone of the investigated estuaries, which may be sporadic and dependent upon anthropogenic activities in the study area.

Nagy, T., Kuki, Á., Nagy, M., Zsuga, M., Kéki, S., 2019. Mass-remainder analysis (MARA): An improved method for elemental composition assignment in petroleomics. Analytical Chemistry 91, 6479-6486.


Data processing and visualization methods have an important role in the mass spectrometric study of crude oils and other natural samples. The recently invented data mining procedure, Mass-Remainder Analysis (MARA), was further developed for use in petroleomics. MARA is based on the calculation of the remainder after dividing by the exact mass of a base unit, in petroleomics by the mass of the CH2 group. The two key steps in the MARA algorithm are the separation of the monoisotopic peaks from the other isotopic peaks and the subsequent intensity correction. The effectiveness of our MARA method was demonstrated on the analysis of lubricating mineral oil and crude oil samples by ultra-high-resolution Fourier transform ion cyclotron resonance mass spectrometry experiments. MARA is able to handle a huge portion of the overlapped peaks even in a moderate resolution mass spectrum. With use of MARA, effective chemical composition assignment and visual representation were achieved for complex mass spectra recorded by a time-of-flight analyzer with a limited resolution of 40 000 at m/z 400. In the absence of an ultra-high-resolution mass analyzer, MARA can provide a closer look on the mass spectral peaks, like a digital zoom in a simple camera.

Napper, I.E., Thompson, R.C., 2019. Environmental deterioration of biodegradable, oxo-biodegradable, compostable, and conventional plastic carrier bags in the sea, soil, and open-air over a 3-year period. Environmental Science & Technology 53, 4775-4783.


There is clear evidence that discarded single-use carrier bags are accumulating in the environment. As a result, various plastic formulations have been developed which state they deteriorate faster and/or have fewer impacts on the environment because their persistence is shorter. This study examined biodegradable, oxo-biodegradable, compostable, and high-density polyethylene (i.e., a conventional plastic carrier bag) materials over a 3 year period. These materials were exposed in three natural environments; open-air, buried in soil, and submersed in seawater, as well as in controlled laboratory conditions. In the marine environment, the compostable bag completely disappeared within 3 months. However, the same compostable bag type was still present in the soil environment after 27 months but could no longer hold weight without tearing. After 9 months exposure in the open-air, all bag materials had disintegrated into fragments. Collectively, our results showed that none of the bags could be relied upon to show any substantial deterioration over a 3 year period in all of the environments. It is therefore not clear that the oxo-biodegradable or biodegradable formulations provide sufficiently advanced rates of deterioration to be advantageous in the context of reducing marine litter, compared to conventional bags.



The Perturbed-Chain Statistical Associating Fluid Theory (PC-SAFT) equation of state (EoS) and the Cubic-Plus-Association (CPA) EoS have been widely applied to describe the asphaltene precipitation onset in crude oils because the association term of these models can appropriately account for the polar-polar interactions between asphaltene and resin molecules. In this study we have compared the PC-SAFT and CPA EoS capabilities in the calculation of the Asphaltene Precipitation Envelope (APE) of eight oils from the literature and discuss the physical meaning of the cross-association energy parameter between asphaltene and resin. For all oils the PC-SAFT EoS predicts an increase in the stability of the oil at higher temperatures with the consequent closure of the APE while the CPA model predicts a decrease in the stability at higher temperatures. For both models the fitted values of the cross-association energy parameter between asphaltene and resin show a dependency on temperature, but for PC-SAFT model this parameter has a clearer physical meaning. Results indicate that the PC-SAFT EoS is more accurate for APE calculations outside the experimental temperature range.



Asphaltene onset pressure (AOP) is a key parameter to determine the flow assurance of live oils. In this study, the capabilities of the cubic-plus-association (CPA) equation of state (EoS) and the Hirschberg method of calculating the AOP of five oils are compared to a new approach using few experimental data. Two experimental data points of AOP and only one of the bubble pressure (BP) are required for adequate parametrization of both models. The number of non-zero binary interaction parameters needed for the CPA EoS is reduced to only four binary pairs. In the Hirschberg method, the BP calculations were performed with the Soave–Redlich–Kwong EoS. For all oils, the CPA EoS provided lower deviations for both AOP and BP. To achieve a good correlation, the Hirschberg method requires the use of AOP experimental data to calculate the difference between the liquid-phase solubility parameter and the asphaltene solubility parameter. Similarly, CPA EoS requires the calculation of the cross-associating energy parameter between asphaltene and resin.

Nelson, R.K., Gosselin, K.M., Hollander, D.J., Murawski, S.A., Gracia, A., Reddy, C.M., Radović, J.R., 2019. Exploring the complexity of two iconic crude oil spills in the Gulf of Mexico (Ixtoc I and Deepwater Horizon) using comprehensive two-dimensional gas chromatography (GC × GC). Energy & Fuels 33, 3925-3933.


Comprehensive two-dimensional gas chromatography (GC × GC) was used to explore and compare the chemical complexity of oil released from the Deepwater Horizon (DWH) disaster in 2010 and the Ixtoc I spill in 1979-1980, both in the Gulf of Mexico (GoM). To provide the most complete inventory of the compounds present in the DWH and Ixtoc I crude oils, we utilized GC × GC systems coupled to a flame ionization detector and a high-resolution time-of-flight mass spectrometric

detector. The results of this study demonstrate the significance of valuable environmental forensics information obtained using GC × GC fingerprinting methods. In particular, the high-resolution mass spectrometer enabled an in-depth characterization of the types and families of GC-amenable compounds present in these crude oils including the detection of highly alkylated sulfur-containing species, alkylated carbazoles and benzocarbazoles, and a suite of unusual de-A-sterane biomarkers in the Ixtoc I oil. This type of specificity is essential for differentiating spill sources of similar origin/type, for example, within northern and southern GoM petroleum families and of the molecular transformations that occur during oil-spill weathering processes.

Neumaier, M., Littke, R., Back, S., Kukla, P., Schnabel, M., Reichert, C., 2019. Hydrocarbon charge assessment of frontier basins – a case study of the oceanic crust of the Moroccan Atlantic margin. Petroleum Geoscience, 151-168.

https://doi.org/10.1144/petgeo2017-109

A string of prominent structural anticlines is located in the deep offshore Atlantic Ocean c. 150 km west of Essaouira (Morocco), possibly forming large traps. However, the basement is inferred to comprise oceanic crust, which raises concerns for source-rock presence and sufficient subsurface temperatures for oil generation. The presented work showcases a hydrocarbon charge assessment approach adapted to the very sparse data context and the specific geodynamic settings of the Moroccan Atlantic margin. Regional 2D basin and petroleum systems modelling was performed to assess possible scenarios of hydrocarbon charge of the deep-water folds, its migration style and timing. Several possible oil and gas generation drivers have been identified for postulated Toarcian marine shale source rocks. These range from simple burial-driven heating to more unique scenarios involving early stage oceanic ridge heating and the effect of the Canary Island hotspot. In particular, the latter might have had a major impact on the oil and gas generation, the migration style and overall accumulated amounts.



In order to investigate the hydrogen isotopic variation of gases sourced from different organic facies, experimental pyrolytic results of a limestone sample (kerogen) and a coal sample from the Zhongbai gas field, Sichuan Basin, and a coal sample from the Songliao Basin, China were compared. The results demonstrate that hydrogen isotopes of methane, ethane and propane all increase with increasing thermal maturity, i.e., thermogenic gases become more enriched in 2H with increasing thermal maturity. There is remarkable variation of hydrogen isotopes of gases sourced from different organic matters. Gases derived from the limestone have the heaviest δ2H, followed by that sourced from the coal in Sichuan Basin and then the coal from Songliao Basin. This trend is just opposite to that of the carbon isotopic variation in different organic facies. Such trend is due to the differences in the salinity of water medium of the depositional environment, rather than the types of the organic matter. Unlike the carbon isotopes, hydrogen isotope is more susceptible to influence from the depositional environments, which might mask the influence from different fractions of the organic matter. Field natural gas samples also proves the strong influence from depositional environment on the hydrogen isotope. This work demonstrates that hydrogen isotope itself is not a reliable index to determine the type of organic matter.

Nielsen, S.B., Jochum, M., Pedro, J.B., Eden, C., Nuterman, R., 2019. Two-timescale carbon cycle response to an AMOC collapse. Paleoceanography and Paleoclimatology 34, 511-523.

https://doi.org/10.1029/2018PA003481

Atmospheric CO2 concentrations (pCO2) varied on millennial timescales in phase with Antarctic temperature during the last glacial period. A prevailing view has been that carbon release and uptake by the Southern Ocean dominated this millennial‐scale variability in pCO2. Here, using Earth System Model experiments with an improved parameterization of ocean vertical mixing, we find a major role for terrestrial and oceanic carbon releases in driving the pCO2 trend. In our simulations, a change in Northern Hemisphere insolation weakens the Atlantic Meridional Overturning Circulation (AMOC) leading to increasing pCO2 and Antarctic temperatures. The simulated rise in pCO2 is caused in equal parts by increased CO2 outgassing from the global ocean due to a reduced biological activity and changed ventilation rates, and terrestrial carbon release as a response to southward migration of the Intertropical Convergence Zone. The simulated terrestrial release of carbon could explain stadial declines in organic carbon reservoirs observed in recent ice core δ13C measurements. Our results show that parallel variations in Antarctic temperature and pCO2 do not necessitate that the Southern Ocean dominates carbon exchange; instead, changes in carbon flux from the global ocean and land carbon reservoirs can explain the observed pCO2 (and δ13C) changes.

Nikolaev, M.Y., Kazak, A.V., 2019. Liquid saturation evaluation in organic-rich unconventional reservoirs: A comprehensive review. Earth-Science Reviews 194, 327-349.


Unconventional organic-rich reservoirs, including oil and gas shales, are the type of rocks located in the subsurface and bearing considerable hydrocarbon resources. Shale gas revolution that started in 2011 raised the question of gas and oil shales properties research all over the world. However, still one of the most critical questions on the subject is the problem of oil and water saturation evaluation in shale reservoirs. An expanded literature survey improved understanding of the current state of the problem, available solutions, including methods, and method-based workflows. Analysis of the obtained information revealed an absence of a universal technique to solve the problem. Application of multi-frequency nuclear magnetic resonance (NMR) coupled with an NMR rock core analyzer optimized for shales forms workflows providing the complete information on the type and volume of fluids present in the pore space of oil shales. The methods delivering incomplete (partial) information include retort analysis, Dean-Stark extraction, rock evaluation (Rock-Eval) pyrolysis, electrical resistivity, and dielectric permittivity measurements. This review aims to provide with comprehensive information on the currently existing methods and workflows used to characterize oil and water saturation in organic-rich unconventional reservoirs.

Ning, D., Zhang, E., Shulmeister, J., Chang, J., Sun, W., Ni, Z., 2019. Holocene mean annual air temperature (MAAT) reconstruction based on branched glycerol dialkyl glycerol tetraethers from Lake Ximenglongtan, southwestern China. Organic Geochemistry 133, 65-76.


Here we investigate the sources of branched glycerol dialkyl glycerol tetraethers (brGDGTs) in Lake Ximenglongtan from southwestern China and present a brGDGTs-based Holocene (∼9.4 cal kyr BP) temperature reconstruction. The similarities in the distributions of brGDGTs between surface sediments and catchment soils indicate that soil is the dominant source of brGDGTs. This contrasts

with the recent emphasis on lacustrine GDGTs in other regional studies. Holocene temperature evolution is characterized by an early cool phase (with a mean annual air temperature (MAAT) of 12.5 °C) prior to 7.6 cal kyr BP, followed by a rapid warming towards the local thermal maximum (MAAT = 13.8 °C) from 7.6 to 5.5 cal kyr BP and a subsequent long-term cooling that ended at 1.5 cal kyr BP. Temperature changes after 1.5 cal kyr BP show high variability and low correspondence to global climate events such as the Medieval Warm Period. Overall Holocene temperature variation has been primarily controlled by boreal summer insolation changes. The larger amplitude (1.5–4.0 °C) in annual cooling during the early Holocene in MAAT contrasts with summer temperature records from this region (range of cooling 0.3–1.0 °C) and indicates the likely influence of lower winter temperature on MAAT variation. We suggest that substantial remnants of the Northern Hemisphere ice-sheets during the early Holocene enhanced the winter westerlies and East Asian winter monsoon (EAWM), and decreased the winter temperature in southwestern China, leading to a cold early Holocene climate.



An improved high-performance anion-exchange chromatography with pulsed amperometric detection (HPAEC-PAD) method is described for the simultaneous determination of neutral sugars (hexoses, pentoses and deoxysugars), alditols and anhydrosugars commonly found in atmospheric and marine samples. The method uses a CarboPac MA1 column, at a flow rate of 0.3 mL min−1, and a NaOH gradient (250–700 mM). The proposed method applies a temperature gradient (from 25 to 28 °C) to the column for the first 30 min of the analysis, followed by a constant temperature at 28 °C until the end of the analysis. These analytical conditions allowed the separation of 15 out of 17 carbohydrates in 75 min with resolution factors better than 0.5 for the critical pairs levoglucosan/arabitol, galactosan/arabinose, arabinose/mannose and glucose/xylose.

The application of this method to field samples revealed that anhydrosugars represented 53% of total neutral carbohydrates (TCHO) in total suspended atmospheric particles (TSP), whereas they were detected for the first time in marine particulate organic matter (POM) and high-molecular-weight dissolved organic matter (HMWDOM) samples accounting 2% and 3% of TCHO, respectively. Levoglucosan and/or galactosan were the major anhydrosugars in all samples however, their concentrations are undoubtedly underestimated because hydrolysis was applied to the marine samples prior to the HPAEC-PAD analysis. Despite this underestimation, their presence in the marine samples clearly indicates possible terrestrial input most likely via atmospheric deposition as these compounds are considered terrestrial burring biomass tracers. Finally, deoxysugars were also detected for the first time in the TSP sample representing 1% of TCHO, while alditols accounted for 0.4% and 0.3% of TCHO in POM and HMWDOM, respectively.

O'Connor, L.K., Robinson, S.A., Naafs, B.D.A., Jenkyns, H.C., Henson, S., Clarke, M., Pancost, R.D., 2019. Late Cretaceous temperature evolution of the southern high latitudes: A TEX86 perspective. Paleoceanography and Paleoclimatology 34, 436-454.

https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/2018PA003546

The Late Cretaceous was a greenhouse world, characterized by elevated temperatures and high atmospheric pCO2. Even in the context of an extreme greenhouse climate, existing planktic

foraminiferal δ18O data from the Falkland Plateau (paleolatitude of ~55°S) suggest anomalous warmth, with sea-surface temperatures (SSTs) >30 °C for much of the Late Cretaceous, followed by sudden cooling in the Campanian. Over the last two decades, there has been discussion as to whether these high δ18O-based SSTs reflect a genuine temperature signal and, if so, whether there was a local temperature anomaly in the South Atlantic or whether the data are representative of zonal paleotemperatures at 55°S. To provide new insights into the degree of ocean warming in the southern high latitudes during the Late Cretaceous (Cenomanian to Campanian), new SST records from the Falkland and Kerguelen Plateaus are presented here using the organic geochemical paleothermometer TetraEther indeX of 86 carbon atoms (TEX86). Overall, the TEX86 data support the δ18O data, indicating extreme and widespread warmth in the middle to high southern latitudes in the Late Cretaceous, with SSTs from 27 to 37 °C. Crucially, the TEX86 data show slow, steady cooling from the Turonian to the Campanian and suggest that temperature gradients during the Campanian did not become as steep as suggested by some planktic foraminiferal data.

Okolo, G.N., Everson, R.C., Neomagus, H.W.J.P., Sakurovs, R., Grigore, M., Bunt, J.R., 2019. The carbon dioxide, methane and nitrogen high-pressure sorption properties of South African bituminous coals. International Journal of Coal Geology 209, 40-53.


In this paper, we report the CO2, CH4 and N2 sorption isotherms of four dry South African bituminous coals at pressures up to 16 MPa at 55 °C. The sorption capacities of the samples with respect to the adsorbate gases decreased in the order: CO2 > CH4  ≈ N2 by weight, and CO2 > CH4  > N2 by volume. A new model, based on a hybrid Dubinin-Radushkevich and Henry law approach (DR-HH) provided substantially better fits to the sorption isotherm data than the previously used modified DR (M-DR) model. Obtained uncertainty metrics show that the DR-HH model generally returned lower error sum of squares (ESS) and root mean square (RMS) residuals, and higher quality of fit (QOF) compared to the M-DR model. The net heat of sorption, βEs, of the samples for the three adsorbate gases were generally low (8.5–12.8 kJ/mol), but comparable to previous determinations of other coals, indicating that physisorption was the dominating sorption mechanism. The sorption capacities of the samples were found to be rank-dependent as they decreased with increasing vitrinite reflectance and elemental carbon content. The micropore properties of the samples as measured by both CO2low-pressure gas adsorption (LPGA) and small angle X-ray scattering (SAXS), impacted the sorption properties of the sample more than both the mesopore and macropore properties determined from N2 LPGA, SAXS, and mercury intrusion porosimetry. The sorption capacities of the samples were found to increase with increasing lithotypes abundance, suggesting that lithotype bandings enhances either the fluid transport processes or the micropore properties of the coal matrix. In addition, it has been demonstrated that critical properties of the adsorbate gases influenced their sorption properties.

Olsen, P.E., Laskar, J., Kent, D.V., Kinney, S.T., Reynolds, D.J., Sha, J., Whiteside, J.H., 2019. Mapping solar system chaos with the geological orrery. Proceedings of the National Academy of Sciences 116, 10664.

http://www.pnas.org/content/116/22/10664.abstract

Significance: The Solar System is chaotic, and precise solutions for the motions of the planets are limited to about 60 million years. Using a network of coring experiments that we call the Geological Orrery (after 18th century planetaria), we recover precise and accurate values for the precession of the perihelion of the inner planets from 223- to 199-million-year-old tropical lake sediments, circumventing the problem of Solar System chaos. Extension of the Geological Orrery from 60

million years ago to the whole Mesozoic and beyond would provide an empirical realm to constrain models of Solar System evolution, further test General Relativity and its alternatives, constrain the existence of additional past planets, and provide further tests of gravitational models.

Abstract: The Geological Orrery is a network of geological records of orbitally paced climate designed to address the inherent limitations of solutions for planetary orbits beyond 60 million years ago due to the chaotic nature of Solar System motion. We use results from two scientific coring experiments in Early Mesozoic continental strata: the Newark Basin Coring Project and the Colorado Plateau Coring Project. We precisely and accurately resolve the secular fundamental frequencies of precession of perihelion of the inner planets and Jupiter for the Late Triassic and Early Jurassic epochs (223–199 million years ago) using the lacustrine record of orbital pacing tuned only to one frequency (1/405,000 years) as a geological interferometer. Excepting Jupiter’s, these frequencies differ significantly from present values as determined using three independent techniques yielding practically the same results. Estimates for the precession of perihelion of the inner planets are robust, reflecting a zircon U–Pb-based age model and internal checks based on the overdetermined origins of the geologically measured frequencies. Furthermore, although not indicative of a correct solution, one numerical solution closely matches the Geological Orrery, with a very low probability of being due to chance. To determine the secular fundamental frequencies of the precession of the nodes of the planets and the important secular resonances with the precession of perihelion, a contemporaneous high-latitude geological archive recording obliquity pacing of climate is needed. These results form a proof of concept of the Geological Orrery and lay out an empirical framework to map the chaotic evolution of the Solar System.

Omar, B., El-Gammal, M., Abou-Shanab, R., Fotidis, I.A., Angelidaki, I., Zhang, Y., 2019. Biogas upgrading and biochemical production from gas fermentation: Impact of microbial community and gas composition. Bioresource Technology 286, 121413.


The present study proposes a novel alternative method of the current biogas upgrading techniques by converting CO2 (in the biogas) into valuable chemicals (e.g., volatile fatty acids) using H2 as energy source and acetogenic mixed culture as biocatalyst. The influence of thermal treatment (90 °C) on the inhibition of the methanogenic archaea and enriching the acetogenic bacteria in different inocula (mesophilic and thermophilic) was initially tested. The most efficient inoculum that achieved the highest performance through the fermentation process was further used to define the optimum H2/CO2

gas ratio that secures maximum production yield of chemicals and maximum biogas upgrading efficiency. In addition, 16S rRNA analysis of the microbial community was conducted at the end of the experimental period to target functional microbes. The maximum biogas content (77% (v/v)) and acetate yield (72%) were achieved for 2H2:1CO2 ratio (v/v), with Moorella sp. 4 as the most dominant thermophilic acetogenic bacterium.



We describe an imaging and pore-scale modelling study of capillary trapping in the Paaratte Sandstone formation in the Otway Basin, Australia. Three-dimensional X-ray computed tomography (micro-CT) was used to characterize the pore structure of the reservoir core. We obtain in-situ pore-

scale images of the distribution of CO2:brine analogue fluid pairs (octane:brine) within reservoir samples during low capillary number drainage and imbibition flooding experiments. The images were recorded using time-lapse X-ray micro-tomography at elevated pressure. The observed two-phase fluid distributions are consistent with a water wet system. The micro-CT images are used directly as input to a geometrically accurate quasi-static pore-scale simulation model. The validity of the quasi-static assumption is investigated by comparing on a pore-by-pore basis the simulated and imaged fluid distributions. The pore filling states are in good agreement both for drainage and imbibition displacements and the computed capillary trapping curve agrees with experimental data. This indicate that quasi-static pore-scale physics can be used to obtain averaged or continuum flow properties for low capillary number displacements. We perform a sensitivity study of the impact of the advancing contact angle on capillary trapping. The magnitude of residual trapping increases with decreasing contact angle. Land's trapping coefficient increases with increasing contact angle. We compute capillary pressure and relative permeability scanning curves. Simulated relative permeability hysteresis is compared with that predicted by the industry-standard Carlson's and Killough's models. Killough's model reproduces the simulated data more accurately.

Oso, S., Walters, M., Schlechter, R.O., Remus-Emsermann, M.N.P., 2019. Utilisation of hydrocarbons and production of surfactants by bacteria isolated from plant leaf surfaces. FEMS Microbiology Letters 366, Article fnz061.


Leaves are covered by a cuticle composed of long (C11-C20) and very-long chain hydrocarbons (>C20), e.g. alkanes, fatty acids, alcohols, aldehydes, ketones and esters. In addition to these aliphatics, cyclic hydrocarbons may be present. Leaves are colonised by a variety of so-called epiphytic bacteria, which may have adapted to be able to utilise cuticle hydrocarbons. We tested the ability of a wide range of phylogenetically different epiphytic bacteria to utilise and grow on diesel and petroleum benzine and show that out of the 21 strains tested, nine had the ability to utilise diesel for growth. Only one strain was able to utilise petroleum benzine for growth. The ability to utilise hydrocarbons for growth correlated with the ability of the strains to produce surfactants and out of the 21 tested strains, 12 produced surfactants. Showing that 75% of the strains producing surfactants were able to degrade hydrocarbons. Our findings suggest that the ability to degrade hydrocarbons and to produce surfactants is highly prevalent in epiphytic bacteria. It is unclear if epiphytic bacteria utilise hydrocarbons originating from the cuticle of living leaves. The application of surfactant producing, hydrocarbon-utilising, epiphytic bacteria might serve as a method for hydrocarbon bioremediation.

Ou, W., Lu, W., Ning, F., Wu, X., 2019. Measurement of methane solubility in pure water in equilibrium with hydrate by using high–pressure optical capillary cell. Marine Chemistry 212, 74-82.


The solubility of methane in aqueous solution in equilibrium with hydrate is an important control on the crystallization and dissolution of methane hydrate. Accurate calibration of Raman spectroscopic measurements of dissolved CH4 with the newly developed Unsaturated Homogenized Solution Method makes possible more accurate measurement of methane solubility across a wide range of pressure conditions. In this study, methane solubilities in pure water in equilibrium with methane hydrate in the absence and presence of a vapor phase were experimentally determined by Raman spectroscopy at temperatures from 273.15 to 293.15 K and pressures from ~2.6 to 120 MPa. The results show that the solubility of CH4 under H–Lw equilibrium increases with temperature at constant pressure but decreases slightly with increasing pressure at constant temperature. The

pressure effect on CH4 solubility in water at H–Lw equilibrium becomes more significant with the increase of temperature. Both the isobaric relationship between ln(mCH4) and 1/T, and the isothermal relationship between ln(mCH4) and P are linear, indicating that the enthalpy change can be considered constant at fixed pressure over the temperature range of 273.15–293.15 K, and the volume change at a given temperature is constant for the methane hydrate dissolution reaction. The values of ΔV range from 9.3 to 12.0 cm3 per mole of hydrate at temperatures between 273.15 and 293.15 K. The Gibbs free energy change is 3.99 to 7.81 kJ∙mol−1 at temperature range from 273.15 K to 293.15 K and pressure range from 10 to 120 MPa. The enthalpy and entropy changes of the methane hydrate dissolution reaction over the studied T–P range are 41.52 to 48.12 kJ∙mol−1 and 0.1282 to 0.1476 kJ∙K−1∙mol−1, respectively. The values increase slightly with increasing pressure.

Padilla, A.M., Loranger, S., Kinnaman, F.S., Valentine, D.L., Weber, T.C., 2019. Modern assessment of natural hydrocarbon gas flux at the Coal Oil Point Seep Field, Santa Barbara, California. Journal of Geophysical Research: Oceans 124, 2472-2484.

https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/2018JC014573

Abstract: The Coal Oil Point seep field is among the most active and studied hydrocarbon seep fields in the world. The water column of the Coal Oil Point seep field was acoustically surveyed from 31 August to 14 September 2016 with a 200-kHz split-beam echo sounder to map the distribution of natural hydrocarbons in the region. An in situ direct capture device was used to measure the volumetric gas flux of natural hydrocarbons for three localized seep sites while simultaneously collecting acoustic volume backscatter measurements of the hydrocarbons within the water column. The acoustic volume backscatter was calibrated with the measured volumetric gas flux, and the resulting relationship was used to determine flux over the entire seep field. The estimate of integrated volumetric gas flow rate over a survey area of approximately 4.1 km2 was 23,800 m3/day. The estimates of integrated volumetric gas flow rate and volumetric gas flux were compared to measurements reported in previous studies and were 2 to 7 times smaller than results obtained by Hornafius et al. (1999, https://doi.org/10.1029/1999JC900148), which had a total survey area of 18 km2. However, differences between methodologies limit the ability to assess natural variability in the Coal Oil Point seep field.

Plain Language Summary: Coal Oil Point is one of the largest and most studied natural underwater hydrocarbon seep sites in the world. Coal Oil Point is located within the Santa Barbara Channel off California's coast, and researchers have been studying this natural hydrocarbon site for five decades to understand how the release of petroleum from the seafloor affects the ocean, atmosphere and living organisms. This study combines acoustic measurements from a broad‐scale survey, with direct observations of gas flow rates, in order to map the contemporary distribution of seeps and obtain estimates of total gas flow rate for the study site. The total gas flow rate for the surveyed area, a total area of 4.1 km2, was approximately 23,800 m3/day. The gas flow rates from this study were compared to estimates reported in previous studies and showed that current gas flow rates range from 2 to 7 times lower than those reported in 1999 (total survey area of 18 km2). However, due to differences in the approaches used to estimate the gas flow rate in the region, it is difficult to address if the change in gas flow rates is caused by natural variability or due to differences in methodology between studies.

Pang, S., 2019. Advances in thermochemical conversion of woody biomass to energy, fuels and chemicals. Biotechnology Advances 37, 589-597.


Biomass has been recognised as a promising resource for future energy and fuels. The biomass, originated from plants, is renewable and application of its derived energy and fuels is close to carbon-neutral by considering that the growing plants absorb CO2 for photosynthesis. However, the complex physical structure and chemical composition of the biomass significantly hinder its conversion to gaseous and liquid fuels. This paper reviews recent advances in biomass thermochemical conversion technologies for energy, liquid fuels and chemicals. Combustion process produces heat or heat and power from the biomass through oxidation reactions; however, this is a mature technology and has been successfully applied in industry. Therefore, this review will focus on the remaining three thermochemical processes, namely biomass pyrolysis, biomass thermal liquefaction and biomass gasification. For biomass pyrolysis, biomass pretreatment and application of catalysts can simplify the bio-oil composition and retain high yield. In biomass liquefaction, application of appropriate solvents and catalysts improves the liquid product quality and yield. Gaseous product from biomass gasification is relatively simple and can be further processed for useful products. Dual fluidised bed (DFB) gasification technology using steam as gasification agent provides an opportunity for achieving high hydrogen content and CO2 capture with application of appropriate catalytic bed materials. In addition, multi-staged gasification technology, and integrated biomass pyrolysis and gasification as well as gasification for poly-generation have attracted increasing attention.

Papanikolaou, S., Aggelis, G., 2019. Sources of microbial oils with emphasis to Mortierella (Umbelopsis) isabellina fungus. World Journal of Microbiology and Biotechnology 35, Article 63.

https://doi.org/10.1007/s11274-019-2631-z

The last years a constantly rising number of publications have appeared in the literature in relation to the production of oils and fats deriving from microbial sources (the “single cell oils”—SCOs). SCOs can be used as precursors for the synthesis of lipid-based biofuels or employed as substitutes of expensive oils rarely found in the plant or animal kingdom. In the present review-article, aspects concerning SCOs (economics, biochemistry, substrates, technology, scale-up), with emphasis on the potential of Mortierella isabellina were presented. Fats and hydrophilic substrates have been used as carbon sources for cultivating Zygomycetes. Among them, wild-type M. isabellina strains have been reported as excellent SCO-producers, with conversion yields on sugar consumed and lipid in DCW values reported comparable to the maximum ones achieved for genetically engineered SCO-producing strains. Lipids produced on glucose contain γ-linolenic acid (GLA), a polyunsaturated fatty acid (PUFA) of high dietary and pharmaceutical importance, though in low concentrations. Nevertheless, due to their abundance in oleic acid, these lipids are perfect precursors for the synthesis of 2nd generation biodiesel, while GLA can be recovered and directed to other usages. Genetic engineering focusing on over-expression of Δ6 and Δ12 desaturases and of C16 elongase may improve the fatty acid composition (viz. increasing the concentration of GLA or other nutritionally important PUFAs) of these lipids.

Parro, V., Puente-Sánchez, F., Cabrol, N.A., Gallardo-Carreño, I., Moreno-Paz, M., Blanco, Y., García-Villadangos, M., Tambley, C., Tilot, V.C., Thompson, C., Smith, E., Sobrón, P., Demergasso, C.S., Echeverría-Vega, A., Fernández-Martínez, M.Á., Whyte, L.G., Fairén, A.G., 2019. Microbiology and nitrogen cycle in the benthic sediments of a glacial oligotrophic deep Andean lake as analog of ancient martian lake-beds. Frontiers in Microbiology 10, 929. doi: 10.3389/fmicb.2019.00929.


Potential benthic habitats of early Mars lakes, probably oligotrophic, could range from hydrothermal to cold sediments. Dynamic processes in the water column (such as turbidity or UV penetration) as

well as in the benthic bed (temperature gradients, turbation, or sedimentation rate) contribute to supply nutrients to a potential microbial ecosystem. High altitude, oligotrophic, and deep Andean lakes with active deglaciation processes and recent or past volcanic activity are natural models to assess the feasibility of life in other planetary lake/ocean environments and to develop technology for their exploration. We sampled the benthic sediments (down to 269 m depth) of the oligotrophic lake Laguna Negra (Central Andes, Chile) to investigate its ecosystem through geochemical, biomarker profiling, and molecular ecology studies. The chemistry of the benthic water was similar to the rest of the water column, except for variable amounts of ammonium (up to 2.8 ppm) and nitrate (up to 0.13 ppm). A life detector chip with a 300-antibody microarray revealed the presence of biomass in the form of exopolysaccharides and other microbial markers associated to several phylogenetic groups and potential microaerobic and anaerobic metabolisms such as nitrate reduction. DNA analyses showed that 27% of the Archaea sequences corresponded to a group of ammonia-oxidizing archaea (AOA) similar (97%) to Nitrosopumilus spp. and Nitrosoarchaeum spp. (Thaumarchaeota), and 4% of Bacteria sequences to nitrite-oxidizing bacteria from the Nitrospira genus, suggesting a coupling between ammonia and nitrite oxidation. Mesocosm experiments with the specific AOA inhibitor 2-Phenyl-4,4,5,5-tetramethylimidazoline-1-oxyl 3-oxide (PTIO) demonstrated an AOA-associated ammonia oxidation activity with the simultaneous accumulation of nitrate and sulfate. The results showed a rich benthic microbial community dominated by microaerobic and anaerobic metabolisms thriving under aphotic, low temperature (4°C), and relatively high pressure, that might be a suitable terrestrial analog of other planetary settings.


https://doi.org/10.1007/s00126-018-0839-8

We present δ60Ni values for black shales, determined by double-spike MC-ICP-MS. The samples comprise Paleoproterozoic Talvivaara Ni–Zn–Co–Cu black shales from Finland, Neoproterozoic black shales from the Teplá-Barrandian Unit, Czech Republic, Early Cambrian Ni–Mo-rich black shales from the Yangtze Craton, and Devonian Ni–Zn–PGE black shales from Yukon, Canada. In addition, the sample set includes a black smoker sample from the Logatchev hydrothermal field, Mid-Atlantic Ridge. The δ60Ni values vary from − 0.84 ± 0.09 to + 0.62 ± 0.04‰ (2SD) with a median of − 0.10‰ (n = 28). Ni isotopic compositions were predominantly lighter than those of abiotic terrestrial and extraterrestrial samples (0.15 and 0.27‰), mantle (0.23‰, Gall et al. 2017), present-day seawater (1.44‰, Cameron and Vance 2014), dissolved Ni from riverine input (0.84‰, Cameron and Vance 2014), ferromanganese crusts (0.9–2.5‰, Gall et al. 2013), Devonian/Mississippian organic-rich marine sediments, lower Jurassic organic-rich marine sediments (0.2–2.5‰, average 0.92‰, n = 18, Porter et al. 2014), and euxinic sediments of the Black Sea (0.14–0.51‰, Vance et al. 2016). However, the range of δ60Ni values in our black shale samples was close to that of the weathering products of mafic/ultramafic rocks (ore and soil samples) ranging from − 0.60 to + 0.30‰ (Ratié et al. 2015; Spivak-Birndorf et al. 2018), Ni-sulfide ores hosted by Archean komatiites from Australia and Canada (− 0.10 to − 1.03‰, average − 0.70‰, n = 8, Gueguen et al. 2013), and Archean Ni-rich magmatic sulfides from Zimbabwe (− 0.28 to − 0.47‰, n = 6, Hoffman et al. 2014). Based on our observations and considering the extremely low contribution of direct biological uptake of Ni, and a dominant Ni residence in early Fe/Ni-sulfides, we suggest that our mostly light Ni isotopic compositions in metal-rich black shales result from sulfidization of organic matter and Ni removal into sulfides.

Pascal, R., 2019. A possible non-biological reaction framework for metabolic processes on early Earth. Nature Astronomy 569, 47-49.

https://www.nature.com/articles/d41586-019-01322-3

Early life forms established a network of reactions for converting carbon dioxide into organic compounds. A non-biological system of reactions that could have formed the network’s core on ancient Earth has been reported.

All biological molecules used by living organisms are themselves synthesized by living organisms. The development of routes for making organic matter was therefore an essential early step in the emergence of life on Earth. A complex network of reactions must have arisen to make organic molecules from carbon dio xide, or possibly from other inorganic sources of carbon such as carbon monoxide or cyanides, but the process involved remains largely unknown. In a paper in Nature, Muchowska et al.1 demonstrate experimentally that a suitable complex reaction network can develop from just two simple organic constituents, namely, glyoxylate (HCOCO2

−) and pyruvate (CH3COCO2

−), in the presence of ferrous iron (Fe2+).

The identified network produces nine of the eleven main components of the tricarboxylic acid (TCA) cycle — the series of reactions by which present-day organisms metabolize organic matter to convert it into energy (Fig. 1), producing the nucleotide ATP as an energy carrier and CO2 as a by-product. The TCA cycle can also work in reverse, in which case it is known as the reductive tricarboxylic acid (rTCA) cycle. The rTCA cycle could have been an early route by which CO2 was converted (fixed) into the organic molecules that are used as the basic components of living organisms. Muchowska and colleagues’ work suggests that the rTCA cycle, as well as other processes that are associated with the metabolism of carbon, could have emerged from a network of abiotic reactions that, at least partly, matched the pattern of the biological reaction network that is now catalysed by enzymes.

The authors also show that, in the presence of hydroxylamine (NH2OH) and metallic iron, their chemical network can be extended to include the formation of four kinds of amino acid, the building blocks of proteins. Both hydroxylamine and metallic iron could have been available on early Earth: hydroxylamine would probably have formed as a result of the rich, abiotic nitrogen chemistry that is known to have occurred early in the planet’s existence2, whereas metallic iron is abundant in certain meteorites that peppered our planet.

Muchowska et al. suggest that their pathway could have developed further to facilitate the subsequent emergence of functional polymers, including peptides and nucleic acids. This would require that abiotic processes that fix CO2 fed the system with glyoxylate and pyruvate. The authors identify evidence from the scientific literature that supports the existence of such processes, but it is unclear whether these processes could have produced sufficient concentrations of glyoxylate and pyruvate to sustain emergent living organisms. This does not invalidate the authors’ reaction network as a potential key player in the origins of life, however.

We are unlikely ever to know for certain whether present-day processes for metabolizing compounds that contain carbon are a purely biochemical innovation, or are instead derived from a prebiotic chemical network. This is because no remnant of the evolutionary processes involved could have persisted for billions of years. Nevertheless, Muchowska and co-workers’ results strongly support the latter possibility. It seems realistic for a rudimentary biological system to have harnessed a pre-existing network by sharing intermediates, and then for it to have gradually become more efficient by evolving genetically encoded catalysts (such as enzymes that directly facilitate the necessary reactions).

The other possibility is that a full set of enzymes that catalyse the essential metabolic steps emerged from scratch. However, this seems highly improbable, because there would have been no selective evolutionary pressure for this to happen in the absence of a pre-existing, analogous system.

Other general themes have been debated by those working in this field. For example, most researchers reject the idea that life began as the result of a sharp transition in complexity from a mixture of organic compounds to a highly organized, self-reproducing entity that looked like a living cell3,4. Instead, life is thought to have originated as the result of gradual improvements to an evolving system that were introduced at separate times5. In this scenario, the distinction between life and non-life is fuzzy, rather than clear-cut6.

Another model builds on the concept of systems chemistry. It suggests that primordial, chemical equivalents of metabolic systems and self-replicating systems could initially have coexisted, but then combined into more-complex systems, perhaps as the result of some kind of compartmentalization process, thereby giving rise to the essential features of life7. But it is unknown whether all three components — metabolism, self-replication and compartmentalization — needed to have coexisted before life emerged. Chemists can contribute to these debates by uncovering a wide range of abiotic processes that might feasibly have occurred on early Earth, as Muchowska and colleagues have done. The authors’ reaction network could have integrated into the process of life’s emergence after the appearance of functional polymers, or contributed to the metabolic component in the systems-chemistry model.

The mystery of the origins of life is not simply a question of how the molecular components of biological systems were formed. If that had been the case, then the puzzle would have been solved soon after 1953, when amino acids were identified as the product of an experiment in which electric sparks were fired into a mixture of simple molecules, to simulate the effects of lightning flashes on early Earth8.

In fact, the most important aspect of life’s emergence was the first implementation of a ‘physical principle’ for natural selection9 — a process by which inheritable improvements can be selected from a population of variants. This, in turn, required molecules or molecular assemblies that can reproduce under certain kinetic constraints, and resulted in the development of a specific kind of stability (known as dynamic kinetic stability10) that is associated with the dynamics of reproduction. This stability has characterized the living state on Earth for billions of years. Nevertheless, life’s requirement for self-replicating molecules does not mean that the contribution of other molecular subsystems (such as reaction networks) was unimportant, if only because such systems might have needed to reach certain concentrations so that self-replicating systems could emerge.

If research on the origins of life is to reach the next level5, several approaches will be needed to provide insight into the process by which life emerged. Identifying abiotic pathways that could have contributed to the overall process is highly valuable, regardless of the stage in life’s evolution at which they were incorporated. Combining systems-chemistry and evolutionary views might be the most productive way forward.

References1. Muchowska, K. B., Varma, S. J. & Moran, J. Nature 569, 104–107 (2019).2. Laneuville, M., Kameya, M. & Cleaves, H. J. II Astrobiology 18, 897–914 (2018).3. Fry, I. in Handbook of Astrobiology (ed. Kolb, V. M.) Ch. 3.1, 109–124 (CRC, 2019).4. Pascal, R., Pross, A. & Sutherland, J. D. Open Biol. 3, 130156 (2013).5. Sutherland, J. D. Nature Rev. Chem. 1, 0012 (2017).6. Bruylants, G., Bartik, K. & Reisse, J. C. R. Chim. 14, 388–391 (2011).7. Ruiz-Mirazo, K., Briones, C. & de la Escosura, A. Chem. Rev. 114, 285–366 (2014).

8. Miller, S. L. Science 117, 528–529 (1953).9. Lotka, A. J. Proc. Natl Acad. Sci. USA 8, 151–154 (1922).10. Pross, A. What is Life? How Chemistry Becomes Biology (Oxford Univ. Press, 2016).

Pavia, F.J., Anderson, R.F., Lam, P.J., Cael, B.B., Vivancos, S.M., Fleisher, M.Q., Lu, Y., Zhang, P., Cheng, H., Edwards, R.L., 2019. Shallow particulate organic carbon regeneration in the South Pacific Ocean. Proceedings of the National Academy of Sciences 116, 9753-9758.


Significance: Plankton in the sunlit surface ocean photosynthesize, fixing dissolved CO2 into particulate organic carbon (POC). This POC sinks and is respired, releasing CO2 into subsurface waters that are sequestered from the atmosphere. The depth scale over which this regeneration happens strongly affects atmospheric CO2, but estimates to date have been sparse and challenging to interpret. We use a new geochemical method to determine POC regeneration depth scales at unprecedented resolution in the South Pacific Ocean, finding shallow regeneration in both oxygen-deficient zone and oligotrophic gyre settings. Our results imply decreased future ocean carbon storage due to gyre expansion and two opposing feedbacks to expanding oxygen-deficient zones, the net effects of which on ocean carbon storage require future research.

Abstract: Particulate organic carbon (POC) produced in the surface ocean sinks through the water column and is respired at depth, acting as a primary vector sequestering carbon in the abyssal ocean. Atmospheric carbon dioxide levels are sensitive to the length (depth) scale over which respiration converts POC back to inorganic carbon, because shallower waters exchange with the atmosphere more rapidly than deeper ones. However, estimates of this carbon regeneration length scale and its spatiotemporal variability are limited, hindering the ability to characterize its sensitivity to environmental conditions. Here, we present a zonal section of POC fluxes at high vertical and spatial resolution from the GEOTRACES GP16 transect in the eastern tropical South Pacific, based on normalization to the radiogenic thorium isotope 230Th. We find shallower carbon regeneration length scales than previous estimates for the oligotrophic South Pacific gyre, indicating less efficient carbon transfer to the deep ocean. Carbon regeneration is strongly inhibited within suboxic waters near the Peru coast. Canonical Martin curve power laws inadequately capture POC flux profiles at suboxic stations. We instead fit these profiles using an exponential function with flux preserved at depth, finding shallow regeneration but high POC sequestration below 1,000 m. Both regeneration length scales and POC flux at depth closely track the depths at which oxygen concentrations approach zero. Our findings imply that climate warming will result in reduced ocean carbon storage due to expanding oligotrophic gyres, but opposing effects on ocean carbon storage from expanding suboxic waters will require modeling and future work to disentangle.

Peng, C., Huang, D., Shi, Y., Zhang, B., Sun, L., Li, M., Deng, X., Wang, W., 2019. Comparative transcriptomic analysis revealed the key pathways responsible for organic sulfur removal by thermophilic bacterium Geobacillus thermoglucosidasius W-2. Science of The Total Environment 676, 639-650.


Biodesulfurization is a promising method to desulfurize sulfur-containing compounds in oil with its unique advantages, such as environment-friendly treatments and moderate reaction conditions. In this study, a thermophilic bacterium Geobacillus thermoglucosidasius W-2 was reported to show nearly 40% and 55% desulfurization rates on heavy oil with 2.81% and 0.46% initial total sulfur content,

respectively. Subsequently, comparative transcriptome analysis indicated that several possible key desulfurization-related genes of this strain were found to be differentially up-regulated induced by benzothiophene and dibenzothiophene, respectively. These desulfurization-related genes were considered to conduct key step to convert organic sulfur to inorganic sulfur. Moreover, the characterization of thermophilic alkanesulfonate monooxygenase systems SsuD1/SsuE1 and SsuD2/SsuE2 revealed that the enzymes exhibit considerable thermal and pH stability and wide substrates applicability. These enzymes probably endowed the strain W-2 with the ability to desulfurize oil and eliminate the sulfur-containing surfactants. Thus, this study provides novel alkanesulfonate monooxygenase systems that have the application potential for heavy oil biodesulfurization, oil demulsification and other biocatalytic processes.

Pérez-Zárate, D., Santoyo, E., Acevedo-Anicasio, A., Díaz-González, L., García-López, C., 2019. Evaluation of artificial neural networks for the prediction of deep reservoir temperatures using the gas-phase composition of geothermal fluids. Computers & Geosciences 129, 49-68.


Three-layer artificial neural networks were used for the multivariate analysis of the gas-phase composition of fluids, and the prediction of geothermal reservoir temperatures. The major gas-phase composition of geothermal fluids (CO2, H2S, CH4, and H2) was defined as input variables whereas the measured bottomhole temperatures were used as output. Multivariate statistical analysis and log-ratio transformations were used for the normalization of input variables. These data sets were randomly divided into training (80%), validation (10%) and testing (10%). Matlab script algorithms based on a learning process of artificial neural networks (ANN) were programmed. The ANN architectures were determined by using up to five input neurons with thirteen different combinations of the input normalized variables for the input layer, a variable number of neurons for the hidden layer ranging from 1 to 35, and one neuron for the output layer. The Levenberg-Marquardt algorithm, the hyperbolic tangent sigmoid, and linear transfer functions were used for the training of the neural networks with tuned learning rates after using some initialization values (ranging from 0.01 to 0.00001). A sensitivity analysis to evaluate the relative importance of input variables on the output was also performed. Six ANN architectures were selected as the best from a comprehensive geochemometric analysis based on a statistical comparison and linear regressions between simulated and measured data. From an additional external validation (using a different geochemical database containing 13 samples from the Olkaria, Kenya geothermal field), the most efficient ANN made possible to predict geothermal reservoir temperatures with an acceptable accuracy (with mean error differences between simulated and measured data ranging from 2 to 11%). The best neural network was given by the ANN-33 architecture [3-8-1] which was characterized by three variables in the input layer [ln(H2S/CO2), ln(CH4/CO2), and ln(H2/CO2)], 8 neurons for the hidden layer and one neuron for the output layer. These results support, for the first time, the use of ANN as a gas geothermometry tool to predict geothermal reservoir temperatures.

Perin, G., Jones, P.R., 2019. Economic feasibility and long-term sustainability criteria on the path to enable a transition from fossil fuels to biofuels. Current Opinion in Biotechnology 57, 175-182.


Currently the production of liquid biofuels relies on plant biomass, which in turn depends on the photosynthetic conversion of light and CO2 into chemical energy. As a consequence, the process is renewable on a far shorter time-scale than its fossil counterpart, thus rendering a potential to reduce the environmental impact of the transportation sector. However, the global economy is not intensively

pursuing this route, as current generation biofuel production does not meet two key criteria: (1) economic feasibility and (2) long-term sustainability. Herein, we argue that microalgal systems are valuable alternatives to consider, although it is currently technologically immature and therefore not possible to reach criterion 1, nor evaluate criterion 2. In this review we discuss the major limiting factors for this technology and highlight how further research efforts could be deployed to concretize an industrial reality.

Persson, E., Capova, K.A., Li, Y., 2019. Attitudes towards the scientific search for extraterrestrial life among Swedish high school and university students. International Journal of Astrobiology 18, 280-288.

https://doi.org/10.1017/S1473550417000556

The aim of this study is to increase our understanding of the attitudes towards the scientific search for extraterrestrial life among high school and university students in Sweden. The most important results of the analysis are that: (a) the great majority of students believe that extraterrestrial life exists; (b) most students regard searching for extraterrestrial life to be quite important or very important; (c) very few students think that we should actively avoid searching for extraterrestrial life; (d) the most common motive for assigning a high priority to search for extraterrestrial life is that it is interesting, the most common motive for assigning a low priority is that such knowledge would not be practically useful, or that the money would be better spent elsewhere; (e) most students do not think they are very well informed regarding the search for extraterrestrial life. A higher percentage of the students who judge themselves to be well informed also believe that extraterrestrial life exists. We have also found some differences between subgroups (men/women, high school students/university students and different fields of study), but the differences are with few exceptions small in comparison with the overall trends, and they mostly differ in degree rather than direction.

Petty, D.M., 2019. An alternative interpretation for the origin of black shale in the Bakken Formation of the Williston Basin. Bulletin of Canadian Petroleum Geology 67, 47-70.

http://archives.datapages.com/data/cspg/data/067/067001/1_cspg670001.htm

Recently, most researchers have argued for a deep-water origin for black shale in the Bakken Formation of the Williston basin based on sedimentology, paleontology and geochemistry characteristics that place black, laminated, sparsely fossiliferous, radiolarian, pyritic shale as the seaward lithology in an assemblage that originally transitioned landward into shallow-water facies. The shallow-water interpretation advocated in this paper is based on stratigraphic characteristics that include the absence of strata that represent a landward equivalent to the shale, gradual landward shale pinchouts, the restriction of Bakken strata to basinal areas, the Bakken onlap depositional style, and placement of a major maximum flooding surface near the base of the overlying Lodgepole.

Black mud deposition in the Bakken is interpreted to have occurred in a low-relief, semi-enclosed, epeiric-lagoon environment with typical water depths of 0–30 m. It is theorized that a high-rainfall climate caused salinity stratification that produced bottom-water anoxia, which preserved organic material. Perhumid climate conditions (year-round rainfall) fostered thick soils and dense vegetation that limited sediment release and induced mud-dominated, sand-poor deposition. During middle Bakken deposition, an arid to semi-arid climate eliminated the bottom-water anoxic conditions and caused carbonate-siliciclastic deposition. The abrupt vertical transitions from black shale (lower Bakken), to carbonate-siliciclastic lithologies (middle Bakken), to black shale (upper Bakken) were caused by paleoclimate change.

Phungsai, P., Kurisu, F., Kasuga, I., Furumai, H., 2019. Molecular characteristics of dissolved organic matter transformed by O3 and O3/H2O2 treatments and the effects on formation of unknown disinfection by-products. Water Research 159, 214-222.


We investigated semiquantitative changes in almost 1000 dissolved organic matter (DOM) features during oxidation with 1 mg of O3 per liter (mg O3/L), 4 mg O3/L, or 4 mg O3/L + 2.5 mg of H2O2 per liter (advanced oxidation process, AOP) by unknown screening analysis with Orbitrap mass spectrometry. The consequential effects on formation of unknown disinfection by-products (DBPs) by chlorination were evaluated in laboratory-scale experiments. Several hundred unsaturated DOM features with positive oxygen-subtracted double bond equivalents per carbon ((DBE–O)/C) were decomposed by the ozone-only treatment and AOP. The AOP decomposed some saturated (negative (DBE–O)/C)) and reduced molecules, which had negative carbon oxidation states (Cos). Several hundred saturated oxidation by-products were detected after ozonation and the AOP. After chlorination, the samples pre-treated with ozone alone resulted in higher formation of unknown DBPs than the AOP pre-treated sample or the sample without oxidation. Over half of the DBP precursors, estimated by electrophilic substitution, were not totally decomposed by any oxidation process, but they were increased after the ozone-only process and AOP. DBP precursors produced by the ozone-only process or AOP formed unique unknown DBPs. Therefore, post-treatment processes after oxidation and before chlorination are important to minimize formation of unknown DBPs.

Piasecki, A., Bernasconi, S.M., Grauel, A.-L., Hannisdal, B., Ho, S.L., Leutert, T.J., Marchitto, T.M., Meinicke, N., Tisserand, A., Meckler, N., 2019. Application of clumped isotope thermometry to benthic foraminifera. Geochemistry, Geophysics, Geosystems 20, 2082-2090.

https://doi.org/10.1029/2018GC007961

Abstract: Obtaining absolute temperatures of the ocean in deep time is complicated by the lack of constraints on seawater chemistry. Seawater salinity, carbonate ion concentration, δ18O, and elemental abundance changes may obscure widely applied paleoproxies. In addition, with foraminifera-based proxies applied over long time scales or through major transitions, taxonomic turnover can impair the robustness of a record. While requiring larger sample sizes than most other proxies, the clumped isotope method is independent of seawater chemistry. Here we test if small benthic foraminifera precipitate their carbonate in equilibrium with respect to the clumped isotope thermometer and if there are any species-specific vital effects. We find that benthic foraminifera fall on the same calibration line as the majority of carbonate minerals including inorganic calcite. In addition, we find no offsets that can be attributed to a species-specific for any of the samples. This finding implies that a necessary amount of sample material can be obtained by aggregating over multiple taxa of benthic foraminifera and allows for the application of this proxy over major climatic transitions that coincide with seawater chemistry changes and foraminifera extinctions.

Piaszczyk, W., Błońska, E., Lasota, J., Lukac, M., 2019. A comparison of C:N:P stoichiometry in soil and deadwood at an advanced decomposition stage. CATENA 179, 1-5.


The aim of this study is to compare the C/N/P stoichiometry of deadwood among four tree species at different stages of decomposition. The way in which the relative concentrations of these elements in

the soil are directly impacted by deadwood decomposition is also explored. First, hornbeam, alder, aspen and fir logs in different decomposition stages (III, IV and V) were selected and sampled. Second, the concentration and stoichiometry of carbon, nitrogen and phosphorous were established. Marked differences in C/N/P stoichiometry were observed between deadwood in an advanced decomposition stage and the soil immediately under the log. The average C/N/P ratio of soil under the influence of deadwood was narrower compared to the C/N/P ratio of deadwood. The C/N/P ratio of studied soils was similar to the expected C/N/P ratio of organic soils or humus. The results indicate that stage of decomposition and tree species have an impact on the elemental stoichiometry of the soil. Thus, C/N/P stoichiometry is a useful indicator of the intensity of nutrient flux from deadwood to the soil.

Piccolo, A., Palin, R.M., Kaus, B.J.P., White, R.W., 2019. Generation of Earth's early continents from a relatively cool Archean mantle. Geochemistry, Geophysics, Geosystems 20, 1679-1697.

https://doi.org/10.1029/2018GC008079

Abstract: Several lines of evidence suggest that the Archean (4.0?2.5 Ga) mantle was hotter than today's potential temperature (TP) of 1350 °C. However, the magnitude of such difference is poorly constrained, with TP estimation spanning from 1500 to 1600 °C during the Meso-Archean (3.2?2.8 Ga). Such differences have major implications for the interpreted mechanisms of continental crust generation on the early Earth, as their efficacy is highly sensitive to the TP. Here we integrate petrological modeling with thermomechanical simulations to understand the dynamics of crust formation during Archean. Our results predict that partial melting of primitive oceanic crust produces felsic melts with geochemical signatures matching those observed in Archean cratons from a mantle TP as low as 1450 °C thanks to lithospheric-scale RayleighTaylor-type instabilities. These simulations also infer the occurrence of intraplate deformation events that allow an efficient transport of crustal material into the mantle, hydrating it.

Plain Language Summary: It has been believed that early Earth featured higher mantle temperature. The mantle temperature affects the geodynamic processes, and, therefore, the production of the continental crust, which has been a stable environment for the developing of life since Earth's infancy. However, our knowledge of the processes operating during the early Earth is still not definitive. The wide range of the mantle temperature estimation (from 1500 to 1600 °C) hampered our ability to understand early Earth's dynamic and geological data alone cannot provide a definitive answer. Therefore, it is necessary to integrate them with numerical modeling. Our contribution conjugates petrological modeling with thermal‐mechanical simulations to unveil the effect of continental crust production. Continental crust's extraction from partially melted hydrated basalts leaves behind dense rocks that sink into the mantle dragging part of surface hydrated rocks. These drips produce a major compositional change of the mantle and promote the production of new basaltic/continental crust. The combination of these processes cools the mantle, suggesting that it could not have been extremely hot for geological timescales. We show that such processes can be active even in a relatively cool mantle (1450–1500 °C), providing new constraints to understand the infancy of our planet.

Pilewski, J., Sharma, S., Agrawal, V., Hakala, J.A., Stuckman, M.Y., 2019. Effect of maturity and mineralogy on fluid-rock reactions in the Marcellus Shale. Environmental Science: Processes & Impacts 21, 845-855.

http://dx.doi.org/10.1039/C8EM00452H

Natural gas extraction from the Appalachian Basin has significantly increased in the past decade. The push to properly dispose, reuse, or recycle the large amounts of produced fluids associated with hydraulic fracturing operations and design better fracturing fluids has necessitated a better understanding of the subsurface chemical reactions taking place during hydrocarbon extraction. Using autoclave reactors, this study mimics the conditions of deep subsurface shale reservoirs to observe the chemical evolution of fluids during the shut-in phase of hydraulic fracturing (HF), a period when hydraulic fracturing fluids (HFFs) remain confined in the reservoir. The experiment was conducted by combining a synthetic hydraulic fracturing fluid and powdered shale core samples in high temperature/pressure static autoclave reactors for 14 days. Shale samples of varying maturity and mineralogy were used to assess the effect of these variations on the proliferation of inorganic ions and low molecular weight volatile organic compounds (VOCs), mainly benzene, toluene, ethylbenzene and xylenes (BTEX) and monosubstituted carboxylic acids. Ion chromatography results indicate that the relative abundance of ions present was similar to that of water produced from HF operations in the Marcellus Shale basin. There was an increase of SO4

2− and PO43− and a decrease in Ba2+ upon

fluid-shale reaction. Major ionic shifts indicate calcite dissolution in two of the fluid-shale reactions and barite precipitation in all fluid-shale reactions. Toluene, xylene, and carboxylic acids were produced in the shale-free control experiment. The most substantial increase in BTEX analytes was observed in reactions with low maturity shale, while the high maturity shale reaction produced no measurable BTEX compounds. Total organic carbon decreased in all reactions including fracturing fluid and shale, suggesting adsorption onto the organic matter (OM) matrix. The results from this study highlight that both the nature of OM and mineralogy play a key role in determining the fate of inorganic and organic compounds during fluid–shale interactions in the subsurface shale reservoir. Overall this study aims to contribute to the growing understanding of complex chemical interactions that occur in the shale reservoirs during HF, which is vital for determining the potential environmental impacts of HF and designing more efficient HFF and produced water recycling techniques for environmentally conscious natural gas production.



The source, thermal maturity, and charge history of oil and gas condensate in the Baiyun depression and the Panyu lower uplift were determined using organic geochemical and fluid inclusion data. Nearly all the gas condensates and oil in the study area originated from Eocene Enping Formation source rocks, whereas the condensate fluids in the eastern area originated from the Enping and Zhuhai Formations. The condensate fluids have a relatively low thermal maturity with a calculated vitrinite reflectance equivalent that typically ranges from 0.8% to 1.0% based on the C29 sterane isomerization ratios and aromatic hydrocarbon maturity parameters. Four types of oil inclusions with various fluorescence colors (yellow–blue) and API gravities (25°–44°) were recognized in the Oligocene and lower Miocene reservoir units, which suggest multiple oil charging events. The homogenization temperatures of the fluid inclusions recorded the oil charge events accompanying large-scale hot fluid movement, which was most likely caused by the charging of high-temperature natural gas from the deeper Wenchang Formation. The trapping pressures of the oil inclusions and the reconstructed burial histories were used to determine the timing of oil charge. The main oil charge occurred from 16–7 Ma throughout the Baiyun depression and Panyu lower uplift, whereas the Panyu lower uplift experienced an additional oil charge from 5–0 Ma. The natural gas charge occurred during the main oil charging period and may continue to the present day. Multiple physical processes, such as gas

injection (without gas exsolution), gas washing (with gas exsolution), and migration fractionation, have played important roles in gas condensate formation and controlling the petroleum distribution in the Baiyun depression and Panyu lower uplift.

Priharto, N., Ronsse, F., Prins, W., Hita, I., Deuss, P.J., Heeres, H.J., 2019. Hydrotreatment of pyrolysis liquids derived from second-generation bioethanol production residues over NiMo and CoMo catalysts. Biomass and Bioenergy 126, 84-93.


Lignin-rich digested stillage from second-generation bioethanol production is a unique biomass-derived feedstock, not only because it contains high amounts of lignin but also due to its residual amounts of cellulose and hemicellulose. In this study, catalytic hydrotreatment experiments were conducted on pyrolysis liquids obtained from the lignin-rich feedstock using sulphided NiMo/Al2O3 and CoMo/Al2O3 catalysts. The aim was to obtain a high conversion of the initial pyrolysis feed into a hydrotreated oil with a high phenolics and aromatics fractions. Experiments were carried out in a stirred batch reactor at 350 °C and 10 MPa of H2 (initial pressure). Product oils were obtained in about 60–65% w/w, the remainder being an aqueous phase (12–14% w/w), solids (7–8% w/w) and gas phase components (all on initial pyrolysis oil feed basis). The product oils were characterised in detail using various techniques (elemental composition, GCxGC-FID, GPC, and 2D HSQC NMR). The oxygen content was reduced from 23% w/w in the pyrolysis oils to 7.5–11.5% in the hydrotreated oils, indicative of the occurrence of hydrodeoxygenation reactions. This was also evident from the chemical composition, showing an increase in the amounts of low molecular weight aromatics, alkylphenolics, alkanes and cycloalkanes in hydrotreated oils. Performance of the two catalysts was compared, and a higher degree of deoxygenation was observed for the NiMo catalyst. The implications of the findings for the valorisation of second-generation bioethanol residues are also discussed.

Pugazhendhi, A., Mathimani, T., Varjani, S., Rene, E.R., Kumar, G., Kim, S.-H., Ponnusamy, V.K., Yoon, J.-J., 2019. Biobutanol as a promising liquid fuel for the future - recent updates and perspectives. Fuel 253, 637-646.


Butanol is a potential alternative fuel for compensating the depletion of fossil based liquid fuels. Butanol can be easily mixed with either gas or petrol, at any percentage and used as a fuel. Clostridia are the main fermentative organisms used for the production of biobutanol. They are potentially known for their capacity to ferment different types of renewable biomass to butanol through the acetone-butanol-ethanol (ABE) fermentation pathway. This review deals with the mechanism of biobutanol production from biomass feedstocks and the issues and challenges involved in the production of biobutanol. The different types of anaerobic biobutanol production namely fed-batch fermentation, continuous fermentation, and two-stage continuous fermentation have been clearly enunciated. Further, different butanol recovery methods such as adsorption, gas stripping and pervaporation have also been discussed in this review. Certain issues affecting the biobutanol production such as sporulation and solventogenesis have been summarized. These types of problems could be overcome by metabolic engineering of Clostridia, which will enhance the resistance of the microorganisms towards high solvent concentrations and thereby increasing the solvent production. The genetic engineering approach is able to overcome the constraints with wild-type strain by understanding the process of solventogenesis in order to construct or modify the strains with improved downstream processing potential for economically advantageous biobutanol production.

Pujalte, V., Monechi, S., Ortíz, S., Orue-Etxebarria, X., Rodríguez-Tovar, F., Schmitz, B., 2019. Microcodium-rich turbidites in hemipelagic sediments during the Paleocene–Eocene Thermal Maximum: Evidence for extreme precipitation events in a Mediterranean climate (Río Gor section, southern Spain). Global and Planetary Change 178, 153-167.


An expanded record (~14 m) of the Paleocene–Eocene Thermal Maximum (PETM), a transient period of extreme global warming that occurred ~56 million years ago, has been found based on calcareous nannofossil and foraminifera stratigraphy in the deep marine Río Gor section, Subbetic Zone, SE Spain. During the early Palaeogene the Subbetic Zone was situated at a mid-palaeolatitude (~32° N), in the NW margin of the Tethyan Ocean. The most prominent features of the studied PETM interval are a significant increase in the proportion of palygorskite, a concurrent decrease in kaolinite and a high content in resedimented Microcodium remains, all of which imply arid/semiarid conditions, one of the distinctive features of the Mediterranean climate. The analysis of the event therefore provides new insights on the hydrological changes induced by the PETM in this climate. Microcodium remains mainly occur at Río Gor in ~450 thin-bedded turbidites, but also occurs redistributed by bioturbation throughout the entire PETM interval, and several centimetres below and above it. Microcodium has a very negative δ13C carbon isotope composition (from −8‰ to −20.7‰), and therefore distorts the global carbon isotopic signature of this thermal event at Río Gor. The increase in palygorskite indicates an intensification of aridity in the study area during the PETM. The Microcodium formed in or around roots of plants growing in subaerially exposed, uplifted massifs of Jurassic carbonates adjacent to the Río Gor area. The resedimentation in the deep sea as turbidites required major runoff episodes after heavy rainfalls. The concurrence of increased aridity and frequent episodes of precipitation extremes demonstrates that the PETM greatly enhanced the typical seasonal contrast of the Mediterranean climate in the Subbetic Zone.

Punshon, S., Azetsu-Scott, K., Sherwood, O., Edinger, E.N., 2019. Bottom water methane sources along the high latitude eastern Canadian continental shelf and their effects on the marine carbonate system. Marine Chemistry 212, 83-95.


Measurements of dissolved methane (CH4) and carbonate system parameters were conducted in shelf and slope waters off Baffin Island and northern Labrador during September 2012 and August 2016 in order to investigate potential cold seeps and their influence on the marine carbonate system. Evidence of a strong near-bottom methane source was found at two sites along the Baffin Island Shelf (Scott Inlet and Cape Dyer) and above a pair of reported sea floor mounds in the Saglek Basin between Baffin Island and northern Labrador. Stable carbon isotope measurements of dissolved methane made at the Cape Dyer site give an estimated δ13C value of −71.2‰ for the source, consistent with microbial methanogenesis. The distributions of pCO2, pH and aragonite and calcite saturation states showed no evidence of enhanced ocean acidification in the vicinity of these sites, so it would seem that these seeps were not significant local sources of carbon dioxide, either as a component in the seep fluid or produced subsequent to release by water column microbial methane oxidation, nonetheless, aragonite saturation states of one or less were seen along the Baffin Island Shelf suggesting that ecosystems here may be vulnerable to further acidification. Spectrophotometric pH measurements of fresh samples in 2012 revealed a bottom water spike in pH at two seep sites that were not replicated by measurements of preserved seawater samples. We hypothesise that this was due to an unstable anionic compound present in seep fluid that can locally increase total alkalinity,

pH and calcium carbonate saturation with HS− being a likely candidate, possibly to the benefit of calcifying organisms in an environment bordering on aragonite under-saturation.

Qiao, J., Cheng, S., Song, W., Jian, C., Wang, W., Zhang, D., Xu, Y., 2019. Probing the effect of NaCl concentrations on a model asphaltene adsorption onto water droplets of different sizes. Energy & Fuels 33, 3881-3890.


While a large amount of attention has been paid to investigating the effects of various factors (e.g., solvent and asphaltene molecular structure) on asphaltene adsorption, the effect of salinity, particularly brine water, has not been systematically studied at the atomistic level despite the ubiquitous presence of salt in crude oil processing. In this work, the adsorption behaviors of a model asphaltene at the oil/brine interface were investigated using molecular dynamics simulations. It was found that the addition of salt greatly enhances the adsorption kinetics in systems with a small droplet, while this enhancement was insignificant for systems with a large droplet. Furthermore, dependent on droplet size, salinity has different effects on the adsorbed structures. In systems with a small droplet, the addition of ions facilitates the direct contact of adsorbed model asphaltene molecules with water surfaces, while in systems with a large droplet, such direct contact was suppressed. Detailed analysis of hydrogen bonding, water/ion distributions, and shape transformation of the water droplet suggests that these observations result from the different degrees of hydration in systems with small and large droplets: small droplets have large surface area to volume ratio, and thus cannot facilitate strong ion hydrations, while large droplets manifest strong ion hydrations, leading to reduced model asphaltene and water attractions. The results reported here can enhance our understanding of emulsification mechanisms in high-salinity crude oil at an atomistic level.

Qin, H., Wang, S., Feng, K., He, Z., Virta, M.P.J., Hou, W., Dong, H., Deng, Y., 2019. Unraveling the diversity of sedimentary sulfate-reducing prokaryotes (SRP) across Tibetan saline lakes using epicPCR. Microbiome 7, 71.

https://doi.org/10.1186/s40168-019-0688-4

Sulfate reduction is an important biogeochemical process in the ecosphere; however, the major taxa of sulfate reducers have not been fully identified. Here, we used epicPCR (Emulsion, Paired Isolation, and Concatenation PCR) technology to identify the phylogeny of sulfate-reducing prokaryotes (SRP) in sediments from Tibetan Plateau saline lakes. A total of 12,519 OTUs and 883 SRP-OTUs were detected in ten lakes by sequencing of 16S rRNA gene PCR amplicons and epicPCR products of fused 16S rRNA plus dsrB gene, respectively, with Proteobacteria, Firmicutes, and Bacteroidetes being the dominant phyla in both datasets. The 120 highly abundant SRP-OTUs (> 1% in at least one sample) were affiliated with 17 described phyla, only 7 of which are widely recognized as SRP phyla. The majority of OTUs from both the whole microbial communities and the SRPs were not detected in more than one specific lake, suggesting high levels of endemism. The α-diversity of the entire microbial community and SRP sub-community showed significant positive correlations. The pH value and mean water temperature of the month prior to sampling were the environmental determinants for the whole microbial community, while the mean water temperature and total nitrogen were the major environmental drivers for the SRP sub-community. This study revealed there are still many undocumented SRP in Tibetan saline lakes, many of which could be endemic and adapted to specific environmental conditions.



The main goal of this study was to investigate the impact of two nonionic surfactants on the solubilization of dense nonaqueous phase liquids (DNAPL) found in crude oils, namely, asphaltenes, from silicate-rich rocks with different mineralogy, pore topology, and wettability states (Bentheimer and Arkose). The surfactants consisted of n-dodecyl β-D-maltoside and triton X-100, which displayed similar properties with the exception of their hydrogen-bonding ability. High-resolution microscope imaging, wettability measurements, and spontaneous imbibition tests were conducted to study the performance of these surfactants on DNAPL solubilization. The interactions between asphaltene molecules, surfactants, and a mineral surface with H-bonding ability were further examined at the molecular-level using molecular dynamics simulations. The results revealed that maltoside could restore the wettability of both sandstones to a higher extent than triton because of its high H-bonding ability with the silanol groups of quartz. This behavior was even more pronounced in tight rocks, such as Arkose, resulting in incremental light nonaqueous phase liquids (LNAPL) mobilization from small pores. Early stages of micellar solubilization of DNAPL by maltoside were successfully observed through molecular dynamics simulations. The solubilization was promoted by surfactant self-assembly, leading to the formation of a continuous surfactant channel that interacted with asphaltenes and promoted their desorption from the mineral surface. This phase eventually grew into a thick surfactant shell trapping DNAPL in its core, as suggested by high-resolution transmission electron microscope (HRTEM) micrographs of microemulsions formed by these NAPL/surfactant-in-brine systems.



The production of synthetic oil-based plastics has led to the accumulation of huge amounts of the plastic waste in the environment, especially in the marine system, very often the final sink for many types of conventional wasted plastics. In particular, (micro)plastics account for the majority of litter items in the marine environment and a high percentage of such litter is originating from land sources. Attempts to mitigate the harmful effects of conventional plastics such as the development of novel management strategies together with the gradual substitution of them with biodegradable (bio)plastics are representing future solutions. However, high amounts of conventional plastics have been accumulating in the environment since several years. Although many studies reported on their potential biodegradation by microbes in and from terrestrial environments, very little is known about the biodegradability of these plastics in freshwater systems and only recently more reports on their biodegradation by marine microorganisms/in marine environment were made available. In this review, we first provide a summary of the approaches applied for monitoring and assessing conventional plastics biodegradation under defined conditions. Then, we reviewed historical and recent findings related to biodegradation of four major plastics produced in European Union (EU), i.e. Polyethylene, Polyvinyl Chloride, Polypropylene and Polystyrene, in terrestrial and aquatic environments and by pure and mixed microbial cultures obtained from them.

Rajak, P.K., Singh, V.K., Singh, P.K., 2019. Distribution of inertinites in the Early Paleogene lignites of western India: On the possibility of wildfire activities. Journal of the Geological Society of India 93, 523-532.

https://doi.org/10.1007/s12594-019-1213-x

In the present investigation 643 samples from early Paleogene lignite seams of western India have been studied to see the distribution of inertinites. These horizons are characterized by high content of charcoal occuring as inertinite in these lignites though there is no definite trend of inertinite distribution in space and time. Bhavnagar lower seam of the Saurashtra basin, Gujarat (BHL-6 band) and Gurha lignite seam of the Bikaner-Nagaur basin, Rajasthan (GU-8 band) recorded the highest level of charcoal to the tune of 25% (mmf basis) while the mean seam value of 16.6% is seen in the Seam-V of Panandhro lignite field of the Kachchh basin, Gujarat. The study is comparable with the wildfire activities of Early Paleogene period occurring in other parts of the world.

Ramcharan, T., Hosein, R., 2019. Radio Frequency Heating combined with Solvent Extraction- A method for oil recovery from surface oil sands. Journal of Petroleum Science and Engineering 179, 328-336.


Trinidad has oil sands resources of about 2 billion barrels of oil on land. However, due to the relatively small extent and surface location (about 10,000 acres and with depths varying from surface to less than 500 feet), large scale surface mining and in-situ methods such as SAGD and VAPEX that are applied to recover oil from Canadian oil sands, are not practical. From experimental and simulation studies conducted, a new method was developed to commercially recover oil from Trinidad's surface oil sands.

The open literature shows Radio Frequency Heating (RFH) to be more practical than electrical resistive heating (ERH) for surface oil sands. RFH is cheaper, quicker and heating is uniform and deeper than ERH, with oil recoveries ranging from 50 to 80%. Experimental studies show the viscosity of Trinidad oil sand oil to be greater than 10,000 cp and temperatures greater than 170 °C are required for the oil to flow. The power requirement for applying RFH at this temperature is greater than 25 kW (kW) and very costly. In addition, vaporisation of oil components occurs at these high temperatures, which is not environmentally safe for surface application.

This new oil recovery method uses RFH at low power (1 kW) with a locally extracted organic solvent. The RFH system designed and assembled consists of an RFH chamber, signal generator and low power amplifier (1 kW). Samples of oil sands were heated in the chamber to 100 °C using a low frequency of 11.5 MHz and a citrus oil extracted in house was injected. Bitumen recoveries in the range 60–70% were achieved after three cycles of solvent injection and RFH.

Experimental studies conducted show that Trinidad oil sands have a clay content in the range of 10–20%, are water wetting with a water saturation in the range 10–20% and have relative permittivities in the range 38–100. From this data, a new mathematical correlation was developed to obtain permittivities of oil sands which can be used with industry software to simulate oil recovery by RFH. Simulation studies show that for a 70% recovery from three cycles, eight gallons of solvent per cycle are required with RFH at a temperature of 100 °C.

The data from the experimental and simulation studies show that with a heating cost of 2.50 USD to produce a barrel of oil, a solvent cost of 16 USD/barrel and with drilling, equipment and operational costs, and this method is viable at an oil price over 25 USD/barrel. The low cost and minimal environmental impact of this new method makes it very attractive for oil extraction from surface oil sands.



Petroprophyrins are biomarkers used to extract information about petroleum genesis among other characteristics. Identification of particular types, such as Ni, Cu, Mn, vanadyl (VO), and oxygenated or sulfur-containing porphyrins, typically involves exhaustive isolation and purification processes followed by high-resolution mass spectrometry analysis using atmospheric pressure photoionization [APPI-(+)] or electrospray [ESI-(+)] sources. Simultaneous identification of all porphyrins present in a particular crude oil or organic-matter-rich sediment still remains an analytical challenge. Here, we report a straightforward petroporphyrin isolation and identification methodology based on a single-step liquid–liquid (L–L) extraction (crude oil: acetonitrile) and high-performance thin-layer chromatography fractionation (HPTLC, aminopropyl-bonded silica) followed by selective ionization via electron transfer in matrix-assisted laser desorption ionization (MALDI-FTICR). Mass spectrometric analysis of the extracts resulted in detection of 350 individual compounds in the acetonitrile extract and 518 in the HPTLC extract, corresponding to the porphyrin families N4VO, N4VO2, N4VO3, N4VOS, and N4Ni as verified by isotopic structure analysis. To the best of our knowledge, this observation constitutes the largest simultaneous identification of Ni, VO, and oxygenated and sulfur-containing porphyrins in a single crude oil sample. In addition, the use of MALDI significantly reduces the amount of sample required for analysis (pico to femtomole levels) in comparison with continuous infusion methods such as APPI and ESI.

Ramu, R., Sain, K., 2019. Characterization of gas hydrates reservoirs in Krishna-Godavari Basin, eastern Indian margin. Journal of the Geological Society of India 93, 539-545.

https://doi.org/10.1007/s12594-019-1215-8

Seismic inversion and attribute analysis techniques are frequently used in oil and gas industries to characterize a hydrocarbon reservoir. The gas hydrate reservoir in the Krishna-Godavari basin, eastern Indian margin, by analysis of highresolution multi-channel seismic (MCS) data has been characterised. The model-based seismic inversion was performed to derive acoustic impedance (3220 m/s*g/cm3) followed by computation of seismic attributes for delineating the bottom simulating reflector or BSR, main marker for gas hydrates, and characterizing the hydrate-bearing sediments. The study shows the characteristics of BSR at a depth of ∼125 m below sea floor (mbsf), and hence the presence of gas hydrates. The high velocity, low amplitude, high instantaneous frequency and low sweetness indicate presence of gas hydrates above the BSR, whereas low velocity, high reflection strength, low frequencies and high sweetness imply free gas underlying the BSR.

Ranjan, S., Todd, Z.R., Rimmer, P.B., Sasselov, D.D., Babbin, A.R., 2019. Nitrogen oxide concentrations in natural waters on early Earth. Geochemistry, Geophysics, Geosystems 20, 2021-2039.

https://doi.org/10.1029/2018GC008082

Abstract: A key challenge in origins-of-life studies is estimating the abundances of species relevant to the chemical pathways proposed to have contributed to the emergence of life on early Earth. Dissolved nitrogen oxide anions (NOx

-), in particular nitrate (NO3-) and nitrite (NO2

-), have been invoked in diverse origins-of-life chemistry, from the oligomerization of RNA to the emergence of protometabolism. Recent work has calculated the supply of NOx

-from the prebiotic atmosphere to the

ocean and reported steady state [NOx-] to be high across all plausible parameter space. These findings

rest on the assumption that NOx- is stable in natural waters unless processed at a hydrothermal vent.

Here, we show that NOx- is unstable in the reducing environment of early Earth. Sinks due to

ultraviolet photolysis and reactions with reduced iron (Fe2+) suppress [NOx-] by several orders of

magnitude relative to past predictions. For pH = 6.5–8 and T = 0–50 °C, we find that it is most probable that [NOx

-] <1μM in the prebiotic ocean. On the other hand, prebiotic ponds with favorable drainage characteristics may have sustained [ NOx

-] ≥1μM. As on modern Earth, most on prebiotic Earth should have been present as , due to its much greater stability. These findings inform the kind of prebiotic chemistries that would have been possible on early Earth. We discuss the implications for proposed prebiotic chemistries and highlight the need for further studies of kinetics to reduce the considerable uncertainties in predicting [NOx

-] on early Earth.

Raven, M.R., Fike, D.A., Gomes, M.L., Webb, S.M., 2019. Chemical and isotopic evidence for organic matter sulfurization in redox gradients around mangrove roots. Frontiers in Earth Science 7, 98. doi: 10.3389/feart.2019.00098.


Coastal environments like mangrove forests are increasingly recognized as potential hotspots for organic carbon burial, giving them a crucial and yet poorly constrained role in the global carbon cycle. Mangrove sediments are frequently anoxic, which facilitates elevated organic matter (OM) burial via several mechanisms, including sulfurization – abiotic reactions between dissolved (poly)sulfide and OM that decrease its lability. Although sulfurization was estimated to account for roughly half of OM preservation in a Bermuda mangrove forest, both its mechanisms and its global significance remain poorly understood. In this study, we investigate S cycling in mangrove forest sediments from Little Ambergris Cay, Turks and Caicos Islands, an environment with predominantly microbial OM inputs and no major source of terrestrial iron. We characterize the S- and C-isotope composition and organic S speciation of sedimentary OM fractions with varying degrees of resistance to acid hydrolysis, along with other inorganic S phases. Near the surface of a 3-mm-diameter, O2-releasing root, abundant organic and elemental S with a 34S-depleted composition indicates microbial sulfur cycling and OM sulfurization. A mixture of pyrite, elemental S, and organic S form a plaque within the outer 50 μm of the root, which also contains strongly 34S-depleted sulfate in its xylem. OM sulfurization products in the sediments include both the alkyl sulfides and disulfides associated with the root plaque and more oxidized forms, especially sulfonates. Hydrolysis-resistant organic S in the sediments is consistently 3–5‰ more 34S-enriched than coexisting elemental S, matching the reported kinetic isotope fractionation factor for OM sulfurization via reaction with polysulfides. These sediments also contain a substantial pool of solid-phase, hydrolyzable organic S with a seawater sulfate-like isotope composition, largely in the form of sulfate esters, which may represent excretions from abundant gastropods. The coexistance of sulfurized OM and aerobic macrofauna highlights how understanding spatial scales and/or temporal cycles in local redox state is critical for predicting net OM preservation, especially in dynamic, coastal environments. Future attempts to mechanistically predict changes in carbon storage in coastal systems will benefit from incorporating OM sulfurization as both a sink for microbially produced sulfide and a mechanism for enhanced carbon sequestration.incorporating OM sulfurization as both a sink for microbially produced sulfide and a mechanism for enhanced carbon sequestration.

Rea, M.A., Shuster, J., Hoffmann, V.E., Schade, M., Bissett, A., Reith, F., 2019. Does the primary deposit affect the biogeochemical transformation of placer gold and associated biofilms? Gondwana Research 73, 77-95.


Placer gold particles derived from epithermal deposits display distinct morphological and compositional features compared with particles from mesothermal systems. Here, it is hypothesized that the chemical composition of primary gold derived from different deposit types is a principle factor affecting the composition of resident biofilm communities as well as the transformation of placer particles. Gold particles were collected from placers originating from the epithermal system at the Eisenberg, Germany's largest primary gold deposit. For comparison, placer gold from mesothermal sources was studied. Morphological differences due to mechanical transport and physical reshaping were not observed. Biogeochemical gold/silver dissolution and gold re-precipitation were evident on epithermal particles and they accentuate the silver-fabrics and gold-rich clusters. In contrast, on mesothermally derived gold particles these processes led to the development of gold-rich rims via the formation of nano-porous secondary gold. Microprobe- and laser ablation mass spectrometric analyses of polished whole particle mounts confirmed differences in gold/silver content/distribution and trace metal content between particles from epi- and mesothermal sources, respectively. On particles from all sites nano- and micro-particulate gold is associated with polymorphic layers. These are composed of microbial cells, extracellular polymeric substances (EPS) and clay-sized minerals. Multivariate statistical analyses shows a significant difference between biofilm communities from epi- vs. mesothermally derived particles, which is linked to the chemical composition of the primary gold. While a number of key-species capable of gold transformation, e.g., Cupriavidus sp., Geobacter sp. and Rhodoferax sp., were detected on particles from both sources, higher numbers of organisms with the potential for gold solubilization, precipitation and detoxification were associated with particles from the epithermal sources. A range of species involved in gold transformation, i.e., Arthrobacter spp., Delftia sp., Shewanella sp., and Stenotrophomonas spp., were detected only on epithermally derived placer gold. This indicates the communities are sensitive to differences in gold/silver and possibly trace metal-cycling, resulting from differences in their content, distribution and mobilization behaviour in epi- vs. mesothermally derived particles. Ultimately, this study shows that the chemical composition of the primary deposit strongly influences the biogeochemical transformation of placer gold and the composition of associated biofilms, whereas physical transformations appear to be largely unaffected.

Reboul, G., Moreira, D., Bertolino, P., Hillebrand-Voiculescu, A.M., López-García, P., 2019. Microbial eukaryotes in the suboxic chemosynthetic ecosystem of Movile Cave, Romania. Environmental Microbiology Reports 11, 464-473.

https://doi.org/10.1111/1758-2229.12756

Movile Cave is a small system of partially inundated galleries in limestone settings close to the Black Sea in Southeast Romania. Isolated from the surface for 6 million years, its sulfidic, methane and ammonia‐rich waters harbour unique chemosynthetic prokaryotic communities that include sulphur and ammonium‐metabolizing chemolithotrophs, methanogens, methanotrophs and methylotrophs. The cave also harbours cave‐dwelling invertebrates and fungi, but the diversity of other microbial eukaryotes remained completely unknown. Here, we apply an 18S rRNA gene‐based metabarcoding approach to study the composition of protist communities in floating microbial mats and plankton from a well‐preserved oxygen‐depleted cave chamber. Our results reveal a wide protist diversity with, as dominant groups, ciliates (Alveolata), Stramenopiles, especially bicosoecids, and jakobids (Excavata). Ciliate sequences dominated both, microbial mats and plankton, followed by either Stramenopiles or excavates. Stramenopiles were more prominent in microbial mats, whereas jakobids dominated the plankton fraction of the oxygen‐depleted water column. Mats cultured in the laboratory were enriched in Cercozoa. Consistent with local low oxygen levels, Movile Cave protists are most likely anaerobic or microaerophilic. Several newly detected OTU clades were very divergent from

cultured species or environmental sequences in databases and represent phylogenetic novelty, notably within jakobids. Movile Cave protists likely cover a variety of ecological roles in this ecosystem including predation, parasitism, saprotrophy and possibly diverse prokaryote‐protist syntrophies.

Reichenbach, S.E., Zini, C.A., Nicolli, K.P., Welke, J.E., Cordero, C., Tao, Q., 2019. Benchmarking machine learning methods for comprehensive chemical fingerprinting and pattern recognition. Journal of Chromatography A 1595, 158-167.


Machine learning (ML) has been used previously to recognize particular patterns of constituent compounds. Here, ML is used with comprehensive chemical fingerprints that capture the distribution of all constituent compounds to flexibly perform various pattern recognition tasks. Such pattern recognition requires a sequence of chemical analysis, data analysis, and pattern analysis. Chemical analysis with comprehensive multidimensional chromatography is a maturing approach for highly effective separations of complex samples and so provides a solid foundation for undertaking comprehensive chemical fingerprinting. Data analysis with smart templates employs marker peaks and chemical logic for chromatographic alignment and peak-regions to delineate chromatographic windows in which analytes are quantified and matched consistently across chromatograms to create chemical profiles that serve as complete fingerprints. Pattern analysis uses ML techniques with the resulting fingerprints to recognize sample characteristics, e.g., for classification. Our experiments evaluated the effectiveness of seventeen different ML techniques for various classification problems with chemical fingerprints from a rich data set from 126 wine samples of different varieties, geographic regions, vintages, and wineries. Results of these experiments showed an accuracy range from 58% to 88% for different ML methods on the most difficult classification problems and 96% to 100% for different ML methods on the least difficult classification problems. Averaged over 14 classification problems, accuracy for the different methods ranged from 80% to 90%, with some relatively simple ML techniques among the top-performing methods.

Rezk, M.G., Foroozesh, J., 2019. Effect of CO2 mass transfer on rate of oil properties changes: Application to CO2-EOR projects. Journal of Petroleum Science and Engineering 180, 298-309.


The performance of any CO2-EOR project relies on the capability of CO2 to change the oil properties at a reasonable period of time. The rate of mass transfer of CO2 into a specific oil controls the rate of oil properties changes. Additionally, the rate of CO2 transfer into an oil sample is dependent on CO2 thermodynamic state which is a function of pressure and temperature. Hence, this study aims to investigate the mass transfer of CO2 into a crude oil at gas and also supercritical state to estimate the rate of resultant changes of the oil properties at these two different states. To do so, two mass transfer pressure decay tests were conducted to study the molecular diffusion of CO2 in a light crude oil at both supercritical and gas states. Later, a mathematical model was used to determine the mass transfer parameters, i.e. diffusion coefficient (D) and interface mass transfer coefficient (k), and the dynamic concentration distribution of CO2 within the oil phase. As a part of this study, the time-dependent changes of the crude oil properties due to the molecular diffusion process of CO2 were also obtained for both supercritical CO2 and CO2 at gas state. For this purpose, the results of pressure decay experiments were combined with the results of additional experiments carried out to measure PVT properties of the CO2-oil system including CO2 solubility, oil swelling, oil viscosity, and interfacial tension (IFT) at various pressures and a constant temperature. The measured mass transfer parameters, i.e. D and k, were found to be higher for CO2 at supercritical state than that at gas state.

The higher diffusivity of the supercritical CO2 in the oil resulted in faster changes of the oil properties as compared to the rate of properties changes by CO2 gas. For instance, it took 2 h for the oil to be swollen by 30% when it was in contact with CO2 at supercritical state as compared to 10 h at gas state. In the case of oil viscosity, for example, during 9 h, 58% reduction in oil viscosity was resulted by supercritical CO2 as compared to 25% reduction by CO2 gas. The results of this study can be used for better planning of CO2-EOR projects and particularly for CO2 Huff and Puff where the soaking time needs to be optimized properly.

Richiano, S., Gómez-Peral, L.E., Varela, A.N., Gómez Dacal, A.R., Cavarozzi, C.E., Poiré, D.G., 2019. Geochemical characterization of black shales from the Río Mayer Formation (Early Cretaceous), Austral-Magallanes Basin, Argentina: Provenance response during Gondwana break-up. Journal of South American Earth Sciences 93, 67-83.


During the Early Cretaceous important changes occurred in South-western Gondwana related to its fragmentation, and South Atlantic Ocean opening. Then, two basins developed in southernmost Patagonia: the Austral-Magallanes Basin and the Rocas Verdes-Magallanes Basin. The Río Mayer Formation corresponds to the initial sedimentary stages of the Austral Basin including black shales, marls and fine-grained sandstones deposited in an outer shelf environment. We studied and sampled three detailed sedimentary logs at Río Guanaco Locality (S 49° 57′ 11"; W 72° 04′ 56″), dividing this unit into three informal sections (lower, middle and upper). Whole rock geochemical analyses were carried out over the three sections with the focus on trace elements, in particular, rare earth elements (REE). While, the lower section of the unit shows an affinity to acid volcanic source areas, the middle and upper sections show an affinity to intermediate source areas. These changes through the Río Mayer Formation can be correlated with the initial magmatic activity hosted in the Southern Patagonian Batholith during the Neocomian. Considering the REE patterns, the lower section of the Río Mayer Formation shows an affinity to the felsic compositions of the Tobífera Formation, while the upper section would be related to the erosion of the Punta Barrosa/Cerro Toro formations of the Rocas Verdes-Magallanes Basin. The clear distinction between the REE patterns of the Río Mayer and Zapata formations is considered evidence of the compartmentalization of these basins during the Early Cretaceous. Finally, the absence of correlation between the geochemistry of the studied unit and the Jurassic volcanic rocks of the Deseado Massif indicates that the north-eastern sector of the basin was not a source area for the Austral Basin, at least during the deposition of the Río Mayer Formation in the study area.

Rijfkogel, L.S., Ghanbarian, B., Hu, Q., Liu, H.-H., 2019. Clarifying pore diameter, pore width, and their relationship through pressure measurements: A critical study. Marine and Petroleum Geology 107, 142-148.


Understanding geometrical and topological properties of the pore space in permeable media is of paramount importance, particularly in oil and gas production. Pore space characteristics such as pore sizes and their probability distributions, as well as pore's connectivity are main factors in the modeling of fluid flow and chemical transport in soils and rocks. A common method to determine the pore size is to convert an implemented pressure via either the Young-Laplace or Kelvin equation by assuming a specific pore shape. Simple geometries such as cylindrical and slit-shaped have been frequently used in the literature, particularly to represent pores and to derive theoretical models estimating permeability from pore-throat size distribution. In this study, we clarify the relationship

between pore diameter (d) and pore width (w), two terms interchangeably used in the literature. The former corresponds to a cylindrical pore, while the latter to a slit-shaped one. We emphasize that d = 2w, in contrast to previously published studies claiming that the diameter of a cylindrical pore is equal to the distance between sides of a slit-shaped pore (i.e., d = w). In addition, we discuss that comparing/combining pore size distribution derived from mercury intrusion porosimetry and that determined from nitrogen adsorption isotherm is not supported, unless the effect of hysteresis is trivial, as most probably the former represents pore-throat while the latter pore-body size distributions.



The stable 13C/12C isotope composition usually varies among different organic materials due to isotope fractionation during biochemical synthesis and degradation processes. Here, we introduce a novel laser ablation-isotope ratio mass spectrometry (LA-IRMS) methodology that allows highly resolved spatial analysis of carbon isotope signatures in solid samples down to a spatial resolution of 10 μm. The presented instrumental setup includes in-house-designed exchangeable ablation cells (3.8 and 0.4 mL, respectively) and an improved sample gas transfer, which allow accurate δ13C measurements of an acryl plate standard down to 0.6 and 0.4 ng of ablated carbon, respectively (standard deviation 0.25‰). Initial testing on plant and soil samples confirmed that microheterogeneity of their natural 13C/12C abundance can now be mapped at a spatial resolution down to 10 μm. The respective δ13C values in soils with C3/C4 crop sequence history varied by up to 14‰ across a distance of less than 100 μm in soil aggregates, while being partly sorted along rhizosphere gradients of <300 μm from Miscanthus plant roots into the surrounding soil. These very first demonstrations point to the appearance of very small metabolic hotspots originating from different natural isotope discrimination processes, now traceable via LA-IRMS.

Rodríguez, E., Elordi, G., Valecillos, J., Izaddoust, S., Bilbao, J., Arandes, J.M., Castaño, P., 2019. Coke deposition and product distribution in the co-cracking of waste polyolefin derived streams and vacuum gas oil under FCC unit conditions. Fuel Processing Technology 192, 130-139.


The effect of co-cracking of high-density polyethylene (HDPE) or its pyrolysis wax together with vacuum gasoil (VGO) has been studied. The aim is to determine the content, nature, and location of coke while analyzing the impact on product distribution in the process. Four different feeds were used (VGO, VGO + 5 wt% HDPE, VGO + 20 wt% of wax, and 100 wt% wax) in experiments performed in a laboratory-scaled riser simulator, with similar conditions to those of the fluid catalytic cracking (FCC) unit: equilibrium catalyst; 530 °C; catalyst/feed mass ratio, 5; contact time, 6 s. The results of the different characterization techniques of the deactivated catalyst and the coke indicate that the catalyst fouling decreases notably by incorporating these waste streams, changing its nature to a more aliphatic (olefinic) one and its location towards the zeolite micropores. On the contrary, the coke formed from the VGO is more evolved and mainly constituted by polyaromatic components deposited on the mesopores of the catalyst matrix. Product distribution is also affected, increasing the yield of light cycle oil and keeping a relatively similar gasoline yield, with greater olefinity and lower aromaticity. Thus, the FCC shows great perspectives to valorize polyolefins, present in waste plastics, at great scale.

Romero Yanes, J.F., Feitosa, F.X., do Carmo, F.R., de Sant’Ana, H.B., 2019. Addition of non-endogenous paraffins in Brazilian crude oils and their effects on emulsion stability and interfacial properties. Energy & Fuels 33, 3673-3680.


The formation of emulsions is recognized to be a challenging problem during crude oil production and processing. Emulsion stability and interfacial properties were investigated in this work for paraffinic modified Brazilian crude oils. Crude oil modifications were made by the addition of two different non-endogenous paraffins, n-hexadecane and a commercial paraffinic pool (melting point range of 53–57 °C), to a heavy crude oil, here, named P1, based on asphaltene destabilization results previously published (Romero Yanes, J. F.; Feitosa, F. X.; do Carmo, F. R.; de Sant’Ana, H. B. Paraffin Effects on the Stability and Precipitation of Crude Oil Asphaltenes: Experimental Onset Determination and Phase Behavior Approach. Fluid Phase Equilib. 2018, 474, 116−125, 10.1016/j.fluid.2018.07.017). Paraffinic modified oils were emulsified with synthetic brine (pH 7 and 60 g L–1 NaCl) to identify the phases of the emulsion formed when varying the water content from 10 to 90% (v/v) and temperature from 30 to 80 °C. From the phase diagrams of the emulsion, it was determined that all paraffinic modified oils allow for the inclusion of at least 10% (v/v) more water as the stable emulsified phase, also with a notable decrease in required energy to promote emulsification. It means that less stir velocity was needed in the emulsification process for paraffinic modified crude oils with a remarkable effect for the paraffinic pool modified sample. Interfacial tension measurements between brine and modified crude oils were evaluated, showing a reduction when compared to the unmodified oil in all of the temperatures tested. These results could be related to the asphaltene solubility variation in modified crude oils. Additionally, wax crystal formation, detected by the wax appearance temperature measurements and polarized light optical microscopy, also contributed to emulsion stability for the crude oil modified with the paraffinic pool.

Ross, M.O., MacMillan, F., Wang, J., Nisthal, A., Lawton, T.J., Olafson, B.D., Mayo, S.L., Rosenzweig, A.C., Hoffman, B.M., 2019. Particulate methane monooxygenase contains only mononuclear copper centers. Science 364, 566-570.


Abstract: Bacteria that oxidize methane to methanol are central to mitigating emissions of methane, a potent greenhouse gas. The nature of the copper active site in the primary metabolic enzyme of these bacteria, particulate methane monooxygenase (pMMO), has been controversial owing to seemingly contradictory biochemical, spectroscopic, and crystallographic results. We present biochemical and electron paramagnetic resonance spectroscopic characterization most consistent with two monocopper sites within pMMO: one in the soluble PmoB subunit at the previously assigned active site (CuB) and one ~2 nanometers away in the membrane-bound PmoC subunit (CuC). On the basis of these results, we propose that a monocopper site is able to catalyze methane oxidation in pMMO.

Editor's Summary: How many metals to oxidize methane? Methane is an important fuel, but there are few direct transformations to partially oxidized products. Bacteria use metalloenzymes to catalyze methane oxidation to methanol, a reaction of industrial interest. Understanding the metal sites that enable this reaction may inspire new biomimetic catalysts. Ross et al. used spectroscopic measurements to assign two monocopper sites in the enzyme particulate methane monooxygenase. These results differ in part from previous proposals for the location and nuclearity of the metal sites and will prompt rethinking about how this metalloenzyme catalyzes methane oxidation.

Rossmassler, K., Snow, C.D., Taggart, D., Brown, C., De Long, S.K., 2019. Advancing biomarkers for anaerobic o-xylene biodegradation via metagenomic analysis of a methanogenic consortium. Applied Microbiology and Biotechnology 103, 4177-4192.

https://doi.org/10.1007/s00253-019-09762-7

Quantifying functional biomarker genes and their transcripts provides critical lines of evidence for contaminant biodegradation; however, accurate quantification depends on qPCR primers that contain no, or minimal, mismatches with the target gene. Developing accurate assays has been particularly challenging for genes encoding fumarate-adding enzymes (FAE) due to the high level of genetic diversity in this gene family. In this study, metagenomics applied to a field-derived, o-xylene-degrading methanogenic consortium revealed genes encoding FAE that would not be accurately quantifiable by any previously available PCR assays. Sequencing indicated that a gene similar to the napthylmethylsuccinate synthase gene (nmsA) was most abundant, although benzylsuccinate synthase genes (bssA) also were present along with genes encoding alkylsuccinate synthase (assA). Upregulation of the nmsA-like gene was observed during o-xylene degradation. Protein homology modeling indicated that mutations in the active site, relative to a BssA that acts on toluene, increase binding site volume and accessibility, potentially to accommodate the relatively larger o-xylene. The new nmsA-like gene was also detected at substantial concentrations at field sites with a history of xylene contamination.

Roy, S., Senger, K., Hovland, M., Römer, M., Braathen, A., 2019. Geological controls on shallow gas distribution and seafloor seepage in an Arctic fjord of Spitsbergen, Norway. Marine and Petroleum Geology 107, 237-254.


This study integrates high-resolution shallow- and deep-geophysical datasets to study the seabed seepage systems linked to subsurface shallow gas and geological features influencing the fluid flow in Nordfjorden, central Spitsbergen (Arctic Norway). This is one of the tributary fjords of the Isfjorden fjord system in Spitsbergen which has the highest density of pockmarks ranging up to 20/km2. The 535 pockmarks identified manually in the 300 km2 large study area have diameters ranging from 10 m to 212 m, and depth varying between 1 m and 8 m. Sub-surface seep-related acoustic features such as, enhanced reflections, acoustic blanking and turbidity zones recorded on 55 km of new high-resolution sub-bottom acoustic data suggest shallow gas (free and/or dissolved) occurrences in the marine sediments beneath the pockmarks. Structural features (thrust faults and associated folds) belonging to the Palaeogene West Spitsbergen fold-and-thrust belt and Early Cretaceous igneous sills have been interpreted on 2D multichannel seismic data, in the Triassic and Permian successions. Some of these faults and igneous sills form seafloor ridges, where pockmark density is high, and they are typically aligned. Acoustic flares attributed to active gas seepage from the seafloor were imaged in the water column in the southern part of Nordfjorden, above the sub-surface shallow gas occurrences and thrust faults. The integrated analysis of these geophysical datasets suggests that the near-seafloor tectonically deformed stratum plays an important role in the up-dip propagation of fluids (liquids and/or gas), distribution of shallow gas in marine sediments, and seepage at the seafloor.



Coal bio-transformation technologies can convert the neglected low rank coal reserves to alternative fuels and non-fuel organic chemicals. Fungal mediated coal degradation can serve as biological beneficiation for alternative substances. For enhanced biodegradation, fungi can be isolated from coal environments and optimized for coal degradation processes. In this study, an indigenous fungal isolate AD-1, identified as Rhizopus oryzae by fungal ITS sequences, was isolated from a low rank coal sample collected from Darra Adam Khel, Frontier Region Kohat, Pakistan. The AD-1 mediated coal degradation was optimized and showed a substantial release of organics at 1.5% glucose and 0.5% coal loading ratio within 11 days. The GC–MS analysis of the black liquid from coal solubilization showed a variety of organic compounds including aromatic acids, fatty acids, alkanes, amines, and amides. The depolymerized liquid extract was analyzed by High-Performance Size-Exclusion Chromatography (HPSEC) for determining the molecular mass distribution of the released organics. The release of the organic fragments had molecular mass distribution ranging between 1.5 kDa and 26.7 kDa. In addition, the released fraction and residual coal sample after solubilization were analyzed with Fourier transform infrared spectroscopy (FT-IR) to explore the structural changes aroused by the AD-1 fungal treatment. The AD-1 fungal strain has the abilities of decarboxylation and deamination, as well as breaking the side chains of the aromatic rings. This demonstrates that indigenous fungi from coal environments can enhance the biodegradation and shows a potential for producing chemical feedstock or alternative fuels from low rank coal.

Saha, R., Uppaluri, R.V.S., Tiwari, P., 2019. Impact of natural surfactant (Reetha), polymer (xanthan gum), and silica nanoparticles to enhance heavy crude oil recovery. Energy & Fuels 33, 4225-4236.


The recovery of heavy crude oil is limited because of the high interfacial tension (IFT) between the crude oil and aqueous phase, which restricts the extent of emulsification and results in poor mobility. This study focuses on the potential of an extracted natural surfactant (Reetha) to recover heavy crude oil by examining various mechanisms accountable for improved oil recovery. The synergy of the natural surfactant, a polymer (xanthan gum), and silica nanoparticles toward the IFT behavior, emulsification, creaming index, rheology, wettability alteration, and core flooding experiments was investigated. The stability of the nanoparticles in the chemical solution was examined by the ζ potential values. Rheology studies were carried out to understand the complexities involved in the system. The core flooding experiments with natural surfactant–polymer chemical solutions resulted in an oil recovery of 18.5% which was enhanced to 27.3% for the nanofluid (natural surfactant–polymer–nanoparticles) system. Thus, the study successfully determines the application of the nanofluid solution to improve the recovery of heavy crude oil.

Sánchez-Quinto, F., Malmström, H., Fraser, M., Girdland-Flink, L., Svensson, E.M., Simões, L.G., George, R., Hollfelder, N., Burenhult, G., Noble, G., Britton, K., Talamo, S., Curtis, N., Brzobohata, H., Sumberova, R., Götherström, A., Storå, J., Jakobsson, M., 2019. Megalithic tombs in western and northern Neolithic Europe were linked to a kindred society. Proceedings of the National Academy of Sciences 116, 9469-9474.


Significance: A new phenomenon of constructing distinctive funerary monuments, collectively known as megalithic tombs, emerged around 4500 BCE along the Atlantic façade. The megalithic phenomenon has attracted interest and speculation since medieval times. In particular, the origin,

dispersal dynamics, and the role of these constructions within the societies that built them have been debated. We generate genome sequence data from 24 individuals buried in five megaliths and investigate the population history and social dynamics of the groups that buried their dead in megalithic monuments across northwestern Europe in the fourth millennium BCE. Our results show kin relations among the buried individuals and an overrepresentation of males, suggesting that at least some of these funerary monuments were used by patrilineal societies.

Abstract: Paleogenomic and archaeological studies show that Neolithic lifeways spread from the Fertile Crescent into Europe around 9000 BCE, reaching northwestern Europe by 4000 BCE. Starting around 4500 BCE, a new phenomenon of constructing megalithic monuments, particularly for funerary practices, emerged along the Atlantic façade. While it has been suggested that the emergence of megaliths was associated with the territories of farming communities, the origin and social structure of the groups that erected them has remained largely unknown. We generated genome sequence data from human remains, corresponding to 24 individuals from five megalithic burial sites, encompassing the widespread tradition of megalithic construction in northern and western Europe, and analyzed our results in relation to the existing European paleogenomic data. The various individuals buried in megaliths show genetic affinities with local farming groups within their different chronological contexts. Individuals buried in megaliths display (past) admixture with local hunter-gatherers, similar to that seen in other Neolithic individuals in Europe. In relation to the tomb populations, we find significantly more males than females buried in the megaliths of the British Isles. The genetic data show close kin relationships among the individuals buried within the megaliths, and for the Irish megaliths, we found a kin relation between individuals buried in different megaliths. We also see paternal continuity through time, including the same Y-chromosome haplotypes reoccurring. These observations suggest that the investigated funerary monuments were associated with patrilineal kindred groups. Our genomic investigation provides insight into the people associated with this long-standing megalith funerary tradition, including their social dynamics.

Sánchez-Sánchez, J., Cerca, M., Alcántara-Hernández, R.J., Lozano-Flores, C., Carreón-Freyre, D., Levresse, G., Vega, M., Varela-Echavarría, A., Aranda-Gómez, J.J., 2019. Extant microbial communities in the partially desiccated Rincon de Parangueo maar crater lake in Mexico. FEMS Microbiology Ecology 95, Article fiz051.

https://doi.org/10.1093/femsec/fiz051

Rincon de Parangueo is a maar where a perennial lake was present until the 1980s. A conspicuous feature of the lake’s sediments is the presence of bioherms and organo-sedimentary deposits produced by microbial communities. The gradual lake desiccation during the last 40 years has produced dramatic environmental changes inside the maar basin, which resulted in the formation of a highly saline-alkaline system with extant microorganisms. In this paper we succinctly describe the geologic setting where the microbial communities have developed inside of the maar crater and the results obtained from high-throughput sequencing methods to characterize the microbial component (Bacteria, Eukarya and Archaea) in endolithic mats of calcareous sediments, and microbial mats and free-living microorganisms in the soda ponds. The studied sites displayed different microbial communities with a diverse number of phylotypes belonging to Bacteria and Eukarya, contrasting with a much less diverse component in Archaea. The sequences here detected were related to environmental sequences from sites with extreme life conditions such as high alkalinity (alkaliphiles), high salinity (halophiles) and high temperature (thermophiles). Moreover, our results indicate an important unexplored endemic microbial biodiversity in the vestiges of the former lake that need to be studied.

Santos, D.C., Filipakis, S.D., Lima, E.R.A., Paredes, M.L.L., 2019. Solubility parameter of oils by several models and experimental oil compatibility data: implications for asphaltene stability. Petroleum Science and Technology 37, 1596-1602.

https://doi.org/10.1080/10916466.2019.1594288

In a previous study we obtained reference values of solubility parameter of two Brazilian crude oils based on asphaltene flocculation data. In this work, these reference values were compared to those obtained by nine models available in the literature and oil compatibility data were experimentally obtained to enhance the modeling evaluation. These evaluations allowed to select models to predict asphaltene stability and oil compatibility. As a result, only our method along with three other methods can accurately predict the experimental results of the compatibility between oil mixtures, and the conclusion is that usually recommended models are not the best choice.

Sanz-Robinson, J., Williams-Jones, A.E., 2019. Zinc solubility, speciation and deposition: A role for liquid hydrocarbons as ore fluids for Mississippi Valley Type Zn-Pb deposits. Chemical Geology 520, 60-68.


Although the ore fluid for Mississippi Valley Type (MVT) deposits is universally considered to be a basinal brine, the common occurrence of liquid hydrocarbons as inclusions in one of the ore minerals (sphalerite) raises the question of whether liquid hydrocarbons could play a role in metal transport. Here we explore the potential of liquid hydrocarbons to act as an ore fluid by determining the steady-state concentration of zinc in crude oil and evaluating the factors that promote its dissolution. To this end, zinc wires were reacted with a series of oils (labelled oils A, B and C) at 150, 200 and 250 °C, and the steady-state concentration of Zn was determined. Zinc concentrations were observed to increase with temperature and with the Total Acid Number (TAN) of the oils, the latter of which is strongly correlated to the carboxylic acid content of crude oil. Crude oil B, the highest TAN oil, dissolved 1700 ± 0.8 ppm at 250 °C, which is comparable to the highest Zn concentration inferred to have been dissolved in brines interpreted to represent MVT ore fluids. X-ray Photoelectron Spectroscopic (XPS) analyses performed on the residual oil coating the zinc wires after the reaction supported the conclusion that Zn has a strong chemical affinity for carboxylic acids in crude oil. Finally, an experiment designed to precipitate sphalerite crystals from a Zn-rich synthetic oil at room temperature showed that sphalerite precipitation from liquid hydrocarbons proceeds efficiently in a carbonate-buffered, H2S -rich environment.

Sarma, V.V.S.S., Sampath Kumar, G., Yadav, K., Dalabehera, H.B., Rao, D.N., Behera, S., Loganathan, J., 2019. Impact of eddies on dissolved inorganic carbon components in the Bay of Bengal. Deep Sea Research Part I: Oceanographic Research Papers 147, 111-120.


To examine the influence of anticyclonic (ACE) and cyclonic (CE) eddies on variations in hydrographic properties and total inorganic carbon system (CT), a study was conducted in the western Bay of Bengal (BoB). The depth of seasonal thermocline, defined as depth of 20 °C isotherm (D20), shoaled (∼80 m) in the CE but deepened to ∼180 m in the ACE relative to non-eddy (NE) conditions (∼110 m) due to convergence and divergence associated with ACE and CE, respectively. Both surface and depth integrated (0–100 m) chlorophyll-a concentrations were higher in CE than in ACE and NE regions suggesting higher primary production in the CE region. Upward displacement

of 2100 μM of CT and 800 μatm of pCO2 isosurfaces from a depth of 175 to 50 m was observed in the CE region resulting in an increase in mixed layer CT and pCO2 compared to that in NE region. Low CT (∼1850 μM) and high pH (∼8.15) isolines deepened to 150–175 m in ACE region. Strong positive relations were observed for CT and pCO2 with salinity whereas weak inverse correlations were found for chlorophyll-a and dissolved oxygen saturation with salinity normalized CT. This suggests that both biological and physical processes control CT in the BoB. Both biological and mixing effects contributed significantly to pCO2 variability in the CE region whereas mixing and thermal effects contributed in the ACE region. The sea-to-air fluxes of CO2 varied between −0.21 and 0.31 molC m−2 month−1. The CE and south ACE (ACEs) regions were found to act as sink for the atmospheric CO2 whereas northern ACE (ACEn) and NE regions were source. The mean CO2 flux suggests that the study region was a moderate source (0.05 ± 0.01 molC m−2 month−1) to the atmosphere. The mean sinking flux of CT to the deeper layer in ACEn and ACEs was ∼0.07 ± 0.02 molC m−2 month−1 whereas it was ∼0.02 ± 0.006 C m−2 month−1 in CE and NE regions. Assuming that the estimated flux at the eddies sampled here is applicable to all eddies in the Bay, the vertical DIC flux to the deep BoB by all eddies amounted to 3.29 ± 0.9 TgC y−1 (1 TgC = 1012 gC). Nevertheless this study suggests that ACEs transports CT to deeper waters, besides being source to the atmospheric CO2.



Asphaltene molecules play a pivotal role in reservoir fluid characterization. As a result of the high complexity of these molecules, there is still an active debate in the scientific community about their physicochemical properties and the structural elucidation, despite a myriad of published studies. It is commonly agreed that asphaltenes, a fraction of reservoir crude oils, exhibit strong interfacial activity and cause many production challenges. In this work, the structure and interfacial activity of 11 characterized asphaltene samples, extracted from 11 different reservoir crude oils from the Middle Eastern region, were analyzed using Raman spectroscopy and pendent drop tensiometry. Additionally, contact angle measurements and atomic force microscopy (AFM) were executed on selected samples. The Raman analysis revealed that the 11 asphaltene batches have similar structural characteristics with the annulated core ranging from 1.43 to 1.66 nm in diameter, which corresponds to 6–7 fused aromatic rings. Interfacial tension (IFT) was measured using the pendent drop technique, by creating a drop of deionized water in a bulk of the respective asphaltene solution in toluene. IFT 90 min values were in the range between 28.3 and 32.6 mN m–1. For one of the asphaltenes, aggregation in the toluene solution was visible by the naked eye. Interestingly, this asphaltene sample showed the weakest influence in terms of IFT reduction, indicating that aggregation reduces the interfacial activity. On the basis of the IFT results, three of the asphaltene samples, exercising different interfacial activity, were investigated for their adsorption tendency toward a carbonate surface using AFM. Topographic images show asphaltene adsorption. The contact angle for water on asphaltene-conditioned surfaces was higher than that for unconditioned surfaces, indicating that the calcite surface was rendered more oil-wet. Increasing the concentration of the asphaltenes in the conditioning solution did not alter the surface to more oil-wet.

Scarcelli, N., Cubry, P., Akakpo, R., Thuillet, A.-C., Obidiegwu, J., Baco, M.N., Otoo, E., Sonké, B., Dansi, A., Djedatin, G., Mariac, C., Couderc, M., Causse, S., Alix, K., Chaïr, H., François, O., Vigouroux, Y., 2019. Yam genomics supports West Africa as a major cradle of crop domestication. Science Advances 5, Article eaaw1947.

http://advances.sciencemag.org/content/5/5/eaaw1947.abstract

While there has been progress in our understanding of the origin and history of agriculture in sub-Saharan Africa, a unified perspective is still lacking on where and how major crops were domesticated in the region. Here, we investigated the domestication of African yam (Dioscorea rotundata), a key crop in early African agriculture. Using whole-genome resequencing and statistical models, we show that cultivated yam was domesticated from a forest species. We infer that the expansion of African yam agriculture started in the Niger River basin. This result, alongside with the origins of African rice and pearl millet, supports the hypothesis that the vicinity of the Niger River was a major cradle of African agriculture.

Scarlett, A.G., Holman, A.I., Georgiev, S.V., Stein, H.J., Summons, R.E., Grice, K., 2019. Multi-spectroscopic and elemental characterization of southern Australian asphaltites. Organic Geochemistry 133, 77-91.


Strandings of various types of bitumen along the coast of southern Australia are long known. Among these, brittle, angular lumps termed ‘asphaltites’ are possibly sourced from Cretaceous source rocks linked to an oceanic anoxic event (OAE), but the exact source remains unclear. The unusual chemical composition of these asphaltites and their survival during transport and shoreline stranding suggest that they formed by nearby submarine seepage of asphaltene-rich crude oils. Here, we provide a detailed organic and inorganic geochemical characterization of asphaltites to constrain their origin and age. High-pressure hydropyrolysis (HyPy) of asphaltene fractions from ten asphaltites released similar assemblages of macromolecularly bound compounds, suggesting a common source for all asphaltites. Comprehensive gas chromatography–time-of-flight mass spectrometry (GC×GC-TOFMS) was used to compare these asphaltene-derived compounds with the maltene fractions, while compound specific isotope analysis (CSIA) was used to compare δ13C and δ2H of n-alkanes and isoprenoids. A large offset between the δ2H of the n-alkanes and isoprenoids suggests oil generation and expulsion at low thermal maturity. The mean concentrations of isorenieratane and chlorobactane, carotenoid derivatives indicative of photic zone euxinia (PZE), in the asphaltites were 8.8 ± 0.8 SEMµgg−1 and 1.4 ± 0.1 SEMµgg−1, respectively. A mean Aryl Isoprenoid Ratio of 0.75 (SD = 0.17) is accompanied by Pr/Ph of ∼1.2. These features strongly support persistent PZE conditions at the level expected for an OAE. Trace metal contents of the asphaltites, including low selenium and high vanadium concentrations, also support anoxic conditions. Rhenium-osmium (Re-Os) analyses constrain the age of asphaltite generation to 103 ± 22 Ma, with a relatively low initial 187Os/188Os ratio of 0.44 ± 0.18. Integrating local geologic knowledge with organic and inorganic geochemistry and Re-Os isotopic results, we identify a Cretaceous unit associated with OAE1a (∼125 Ma) as the most likely source of the asphaltites. Alternative scenarios involving source rocks deposited during OAE1b (∼112 Ma) are possible, but require rapid burial of organic-rich sediments to reach required maturation levels in a shorter time.

Schlüter, R., Dallinger, A., Kabisch, J., Duldhardt, I., Schauer, F., 2019. Fungal biotransformation of short-chain n-alkylcycloalkanes. Applied Microbiology and Biotechnology 103, 4137-4151.

https://doi.org/10.1007/s00253-019-09749-4

The cycloalkanes, comprising up to 45% of the hydrocarbon fraction, occur in crude oil or refined oil products (e.g., gasoline) mainly as alkylated cyclohexane derivatives and have been increasingly found in environmental samples of soil and water. Furthermore, short-chain alkylated cycloalkanes

are components of the so-called volatile organic compounds (VOCs). This study highlights the biotransformation of methyl- and ethylcyclohexane by the alkane-assimilating yeast Candida maltosa and the phenol- and benzoate-utilizing yeast Trichosporon mucoides under laboratory conditions. In the course of this biotransformation, we detected 25 different metabolites, which were analyzed by HPLC and GC-MS. The biotransformation process of methylcyclohexane in both yeasts involve (A) ring hydroxylation at different positions (C2, C3, and C4) and subsequent oxidation to ketones as well as (B) oxidation of the alkyl side chain to hydroxylated and acid products. The yeast T. mucoides additionally performs ring hydroxylation at the C1-position and (C) oxidative decarboxylation and (D) aromatization of cyclohexanecarboxylic acid. Both yeasts also oxidized the saturated ring system and the side chain of ethylcyclohexane. However, the cyclohexylacetic acid, which was formed, seemed not to be substrate for aromatization. This is the first report of several new transformation reactions of alkylated cycloalkanes for eukaryotic microorganisms.

Schobben, M., van de Schootbrugge, B., 2019. Increased stability in carbon isotope records reflects emerging complexity of the biosphere. Frontiers in Earth Science 7, 87. doi: 10.3389/feart.2019.00087.


Preference for certain stable isotopes (isotope fractionation) during enzyme-mediated reactions is a universal aspect of life. For instance, carbon isotopes are fractionated during anabolic (e.g. photosynthate production) and catabolic (e.g. methanogenesis) reactions. These biological processes exert a major control on ambient micro-scale chemical conditions as well as the large-scale exogenic carbon reservoir. Combined with the ubiquity of bio-mediated carbonate mineral nucleation and obligate enzymatic skeletonization, these biochemical reactions and their control on the exogenic carbon pool are known to leave distinct imprints on carbonate minerals which accumulate as sediments throughout Earth’s history. Here, we study the evolution of the marine carbonate-carbon isotope record based on database compilations from the Precambrian and the Phanerozoic. By looking at the frequency distribution of the amplitude of stratigraphic variation at various temporal resolutions, we assess trends in the carbonate-carbon isotope variability. Part of this variation can only be explained by authigenic and diagenetic carbonate mineral additions, which carry metabolic carbon isotope signatures created in the vicinity of cells and secluded (sub-)seafloor micro-environments. It can be envisioned that compartmentalization (membrane enclosed regions), the accumulation of extracellular polymeric substances (biofilms), and restricted fluid exchange in the early diagenetic environment can create sharp isotope gradients that lead to a high-order of micro-scale carbon isotope variability being imprinted in carbonate rock. The frequency of the high-amplitude variation diminishes with the development of more complex life (metazoan-dominated biosphere); presumably through the dispersing action of bioturbation (eradicating these micro-environments), increased grazing pressure and the advent of obligate biomineralization. On the other hand, stark chemical gradients in a world dominated by unicellular life (prokaryotes and to a lesser extent eukaryotes) are thought to leave a distinctly more variable C isotope signature in carbonate rock. An enhanced understanding of the biogenicity of carbonate carbon isotope signatures at multiple spatial and temporal scales provides a baseline that is usable in the search for signs of (past) extraterrestrial life.

Scholz, F., Beil, S., Flögel, S., Lehmann, M.F., Holbourn, A., Wallmann, K., Kuhnt, W., 2019. Oxygen minimum zone-type biogeochemical cycling in the Cenomanian-Turonian Proto-North Atlantic across Oceanic Anoxic Event 2. Earth and Planetary Science Letters 517, 50-60.


Oceanic Anoxic Events (OAEs) in Earth's history are regarded as analogues for current and future ocean deoxygenation, potentially providing information on its pacing and internal dynamics. In order to predict the Earth system's response to changes in greenhouse gas concentrations and radiative forcing, a sound understanding of how biogeochemical cycling differs in modern and ancient marine environments is required. Here, we report proxy records for iron (Fe), sulfur and nitrogen cycling in the Tarfaya upwelling system in the Cretaceous Proto-North Atlantic before, during and after OAE2 (∼93 Ma). We apply a novel quantitative approach to sedimentary Fe speciation, which takes into account the influence of terrigenous weathering and sedimentation as well as authigenic Fe (non-terrigenous, precipitated onsite) rain rates on Fe-based paleo-redox proxies. Generally elevated ratios of reactive Fe (i.e., bound to oxide, carbonate and sulfide minerals) to total Fe (FeHR/FeT) throughout the 5 million year record are attributed to transport-limited chemical weathering under greenhouse climate conditions. Trace metal and nitrogen isotope systematics indicate a step-wise transition from oxic to nitrogenous to euxinic conditions over several million years prior to OAE2. Taking into consideration the low terrigenous sedimentation rates in the Tarfaya Basin, we demonstrate that highly elevated FeHR/FeT from the mid-Cenomanian through OAE2 were generated with a relatively small flux of additional authigenic Fe. Evaluation of mass accumulation rates of reactive Fe in conjunction with the extent of pyritization of reactive Fe reveals that authigenic Fe and sulfide precipitation rates in the Tarfaya Basin were similar to those in modern upwelling systems. Because of a smaller seawater nitrate inventory, however, chemolithoautotrophic sulfide oxidation with nitrate was less efficient in preventing hydrogen sulfide release into the water column. As terrigenous weathering and sediment flux determine how much authigenic Fe is required to generate an anoxic euxinic or ferruginous proxy signature, we emphasize that both have to be taken into account when interpreting Fe-based paleo-redox proxies.


https://doi.org/10.1093/femsec/fiz062

Cable bacteria belonging to the family Desulfobulbaceae couple sulfide oxidation and oxygen reduction by long-distance electron transfer over centimeter distances in marine and freshwater sediments. In such habitats, aquatic plants can release oxygen into the rhizosphere. Hence, the rhizosphere constitutes an ideal habitat for cable bacteria, which have been reported on seagrass roots recently. Here, we employ experimental approaches to investigate activity, abundance, and spatial orientation of cable bacteria next to the roots of the freshwater plant Littorella uniflora. Fluorescence in situ hybridization (FISH), in combination with oxygen-sensitive planar optodes, demonstrated that cable bacteria densities are enriched at the oxic–anoxic transition zone next to roots compared to the bulk sediment in the same depth. Scanning electron microscopy showed cable bacteria along root hairs. Electric potential measurements showed a lateral electric field over centimeters from the roots, indicating cable bacteria activity. In addition, FISH revealed that cable bacteria were present in the rhizosphere of Oryza sativa (rice), Lobelia cardinalis and Salicornia europaea. Hence, the interaction of cable bacteria with aquatic plants of different growth forms and habitats indicates that the plant root–cable bacteria interaction might be a common property of aquatic plant rhizospheres.


http://aem.asm.org/content/85/10/e00086-19.abstract

Abstract: Western Canada produces large amounts of bitumen, a heavy, highly weathered crude oil. Douglas Channel and Hecate Strait on the coast of British Columbia are two water bodies that may be impacted by a proposed pipeline and marine shipping route for diluted bitumen (dilbit). This study investigated the potential of microbial communities from these waters to mitigate the impacts of a potential dilbit spill. Microcosm experiments were set up with water samples representing different seasons, years, sampling stations, and dilbit blends. While the alkane fraction of the tested dilbit blends was almost completely degraded after 28 days, the majority of the polycyclic aromatic hydrocarbons (PAHs) remained. The addition of the dispersant Corexit 9500A most often had either no effect or an enhancing effect on dilbit degradation. Dilbit-degrading microbial communities were highly variable between seasons, years, and stations, with dilbit type having little impact on community trajectories. Potential oil-degrading genera showed a clear succession pattern and were for the most part recruited from the “rare biosphere.” At the community level, dispersant appeared to stimulate an accelerated enrichment of genera typically associated with hydrocarbon degradation, even in dilbit-free controls. This suggests that dispersant-induced growth of hydrocarbon degraders (and not only increased bioavailability of oil-associated hydrocarbons) contributes to the degradation-enhancing effect previously reported for Corexit 9500A.

Importance:Western Canada hosts large petroleum deposits, which ultimately enter the market in the form of dilbit. Tanker-based shipping represents the primary means to transport dilbit to international markets. With anticipated increases in production to meet global energy needs, the risk of a dilbit spill is expected to increase. This study investigated the potential of microbial communities naturally present in the waters of a potential dilbit shipping lane to mitigate the effects of a spill. Here we show that microbial degradation of dilbit was mostly limited to n-alkanes, while the overall concentration of polycyclic aromatic hydrocarbons, which represent the most toxic fraction of dilbit, decreased only slightly within the time frame of our experiments. We further investigated the effect of the oil dispersant Corexit 9500A on microbial dilbit degradation. Our results highlight the fact that dispersant-associated growth stimulation, and not only increased bioavailability of hydrocarbons and inhibition of specific genera, contributes to the overall effect of dispersant addition.addition.

Schreuder, L.T., Donders, T.H., Mets, A., Hopmans, E.C., Sinninghe Damsté, J.S., Schouten, S., 2019. Comparison of organic and palynological proxies for biomass burning and vegetation in a lacustrine sediment record (Lake Allom, Fraser Island, Australia). Organic Geochemistry 133, 10-19.


Continental fire and vegetation history have been studied in sedimentary archives using palynological proxies (i.e. charcoal abundance and the pollen assemblage) and organic proxies (i.e. the anhydrosugars levoglucosan and it isomers, and plant-wax n-alkanes), but rarely in concert. Here, we compared palynological and organic proxies to reconstruct fire and vegetation history in a sediment core from Lake Allom on Fraser Island, Australia, covering the last 5.4 kyrs. We found that anhydrosugar and microscopic charcoal accumulation rates had similar trends, while trends in macroscopic charcoal accumulation rates were different. This was attributed to the short distance over which macroscopic charcoal is transported compared to microscopic charcoal and anhydrosugars. Furthermore, differences in fire regime and combusted types of vegetation may also explain the differences in levoglucosan and charcoal accumulation rates in lacustrine sediments. Moreover, we found that the ratios between anhydrosugars seem to be governed by combustion conditions, or by type of burned vegetation. Long chain n-alkane accumulation rates and stable isotope compositions showed similar patterns to the pollen assemblage throughout the last 5.4 kyrs, with both representing the local vegetation history. Collectively, our results showed that in the period between 5.4 and 4 ka, biomass burning was low on Fraser Island, while at 4 ka, fire occurrence started to increase, slightly earlier than changes in vegetation and hydrology. Therefore, we suggest that increased fire activity on

Fraser Island around 4 ka might have been caused by human-lit biomass burning, since aboriginals settled on Fraser Island around this time.

Schroeder, H., Margaryan, A., Szmyt, M., Theulot, B., Włodarczak, P., Rasmussen, S., Gopalakrishnan, S., Szczepanek, A., Konopka, T., Jensen, T.Z.T., Witkowska, B., Wilk, S., Przybyła, M.M., Pospieszny, Ł., Sjögren, K.-G., Belka, Z., Olsen, J., Kristiansen, K., Willerslev, E., Frei, K.M., Sikora, M., Johannsen, N.N., Allentoft, M.E., 2019. Unraveling ancestry, kinship, and violence in a Late Neolithic mass grave. Proceedings of the National Academy of Sciences 116, 10705-10710.


Significance: We sequenced the genomes of 15 skeletons from a 5,000-y-old mass grave in Poland associated with the Globular Amphora culture. All individuals had been brutally killed by blows to the head, but buried with great care. Genome-wide analyses demonstrate that this was a large extended family and that the people who buried them knew them well: mothers are buried with their children, and siblings next to each other. From a population genetic viewpoint, the individuals are clearly distinct from neighboring Corded Ware groups because of their lack of steppe-related ancestry. Although the reason for the massacre is unknown, it is possible that it was connected with the expansion of Corded Ware groups, which may have resulted in violent conflict.

Abstract: The third millennium BCE was a period of major cultural and demographic changes in Europe that signaled the beginning of the Bronze Age. People from the Pontic steppe expanded westward, leading to the formation of the Corded Ware complex and transforming the genetic landscape of Europe. At the time, the Globular Amphora culture (3300–2700 BCE) existed over large parts of Central and Eastern Europe, but little is known about their interaction with neighboring Corded Ware groups and steppe societies. Here we present a detailed study of a Late Neolithic mass grave from southern Poland belonging to the Globular Amphora culture and containing the remains of 15 men, women, and children, all killed by blows to the head. We sequenced their genomes to between 1.1- and 3.9-fold coverage and performed kinship analyses that demonstrate that the individuals belonged to a large extended family. The bodies had been carefully laid out according to kin relationships by someone who evidently knew the deceased. From a population genetic viewpoint, the people from Koszyce are clearly distinct from neighboring Corded Ware groups because of their lack of steppe-related ancestry. Although the reason for the massacre is unknown, it is possible that it was connected with the expansion of Corded Ware groups, which may have resulted in competition for resources and violent conflict. Together with the archaeological evidence, these analyses provide an unprecedented level of insight into the kinship structure and social behavior of a Late Neolithic community.

Schwaiger-Haber, M., Hermann, G., El Abiead, Y., Rampler, E., Wernisch, S., Sas, K., Pennathur, S., Koellensperger, G., 2019. Proposing a validation scheme for 13C metabolite tracer studies in high-resolution mass spectrometry. Analytical and Bioanalytical Chemistry 411, 3103-3113.

https://doi.org/10.1007/s00216-019-01773-7

13C metabolite tracer and metabolic flux analyses require upfront experimental planning and validation tools. Here, we present a validation scheme including a comparison of different LC methods that allow for customization of analytical strategies for tracer studies with regard to the targeted metabolites. As the measurement of significant changes in labeling patterns depends on the spectral accuracy, we investigate this aspect comprehensively for high-resolution orbitrap mass spectrometry combined with reversed-phase chromatography, hydrophilic interaction liquid

chromatography, or anion-exchange chromatography. Moreover, we propose a quality control protocol based on (1) a metabolite containing selenium to assess the instrument performance and on (2) in vivo synthesized isotopically enriched Pichia pastoris to validate the accuracy of carbon isotopologue distributions (CIDs), in this case considering each isotopologue of a targeted metabolite panel. Finally, validation involved a thorough assessment of procedural blanks and matrix interferences. We compared the analytical figures of merit regarding CID determination for over 40 metabolites between the three methods. Excellent precisions of less than 1% and trueness bias as small as 0.01–1% were found for the majority of compounds, whereas the CID determination of a small fraction was affected by contaminants. For most compounds, changes of labeling pattern as low as 1% could be measured.

Schwanz, T.G., Bokowski, L.V.V., Marcelo, M.C.A., Jandrey, A.C., Dias, J.C., Maximiano, D.H., Canova, L.S., Pontes, O.F.S., Sabin, G.P., Kaiser, S., 2019. Analysis of chemosensory markers in cigarette smoke from different tobacco varieties by GC×GC-TOFMS and chemometrics. Talanta 202, 74-89.


Commercial cigarettes are made from a blend of different tobacco varieties, which in turn are the results of different agronomic practices and post-harvest curing processes. The highly complex mixture of smoke compounds reflects each tobacco variety and the levels of sensory-relevant markers. Therefore, the aim of this work was to identify potential relevant chemosensory markers in the mainstream smoke of four main types of commercial tobaccos and establish any possible relationship between them and the tobacco growing/curing practices. The tobacco samples were segregated into four segments: (1) three curing stages of flue-cured Virginia, (2) three curing stages of air-cured Burley, (3) three geo-regions of sun-cured Oriental and (4) three different process applied to tobacco. One hundred and twenty cigarettes (10 batches per flavour category) were produced and smoked under standard machine-smoking protocols. The mainstream smoke samples collected were extracted and analysed by GC × GC TOFMS. The processed data was analysed by partial least square discriminant analysis (PLS-DA) and the selectivity ratio was used to identify key chemosensory markers responsible for the four segments. All models had sensitivity and specificity equal to unity. Flue-cured Virginia (193 markers) and air-cured Burley (184 markers) showed a similar trend for O-heterocycles markers in the lighter leaf colours and N-heterocycles in the darker leaf colours post-processing, but they had compounds of different flavour descriptions, e. g. sweet and nutty. The three geo-regions of sun-cured Oriental (290 markers) also presented O-heterocycles markers in correlation with leaf sugar contents in addition of sucrose esters markers. The three unusually processed tobacco generated many chemical markers (436 markers), some derived from the so-called Cavendish fermentation process with sweet, spicy and peppery notes, whereas the dark fermented air-cured tobacco presented similar descriptors as air-cured Burley. In addition, some polycyclic aromatic hydrocarbons (PAH) were detected as markers from the fire-curing process. The PLS-DA with selectivity ratio evidenced total of 1098 chemosensory markers in cigarette smoke, in which 173 were tentatively identified.

Sedláček, I., Pantůček, R., Králová, S., Mašlaňová, I., Holochová, P., Staňková, E., Vrbovská, V., Švec, P., Busse, H.-J., 2019. Hymenobacter amundsenii sp. nov. resistant to ultraviolet radiation, isolated from regoliths in Antarctica. Systematic and Applied Microbiology 42, 284-290.


A group of thirteen bacterial strains was isolated from rock samples collected in a deglaciated northern part of James Ross Island, Antarctica. The cells were rod-shaped, Gram-stain-negative, non-motile, catalase positive, and produced moderately slimy, ultraviolet light (UVC)-irradiation-resistant and red–pink pigmented colonies on R2A agar. A polyphasic taxonomic approach based on 16S rRNA gene sequencing, extensive biotyping, fatty acid profile, chemotaxonomy analyses, and whole genome sequencing were applied in order to clarify the taxonomic position of these isolates. Phylogenetic analysis based on the 16S rRNA gene indicated that all isolates constituted a coherent group belonging to the genus Hymenobacter. The closest relatives to the representative isolate P5136T

were Hymenobacter psychrophilus BZ33rT and Hymenobacter rubripertinctus CCM 8852T, exhibiting 97.53% and 97.47% 16S rRNA pairwise similarity, respectively. Average nucleotide identity calculated from the whole-genome sequencing data supported the finding that P5136T represents a distinct Hymenobacter species. The major components in fatty acid profiles were Summed Feature 3 (C16:1 ω7c/C16:1 ω6c), C16:1 ω5c, C15:0 iso and C15:0 anteiso. The cellular quinone content contained unanimously menaquinone MK-6 and MK-7 (ratio 1:5.1). The predominant polar lipid was phosphatidylethanolamine, and moderate to minor amounts of two unknown polar lipids, two unknown aminolipids, one unknown glycolipid and two unknown glycophospholipids were present. The G+C content of genomic DNAs is 60.31mol%. Based on all the obtained results, we propose a novel species for which the name Hymenobacter amundsenii sp. nov. is suggested, with the type strain P5136T (=CCM 8682T=LMG 29687T).

Sermoud, V.M., Barbosa, G.D., Barreto, A.G., Tavares, F.W., 2019. Reconstruction of the pore size distribution of porous materials: The influence of uncertainties in the gaseous adsorption experimental data. Fluid Phase Equilibria 494, 93-102.


Considering the characterization of the pore size distribution, for mesoporous and microporous materials, the recommendation of IUPAC is the deconvolution of the integral adsorption equation, using a kernel calculated with the Non-Local Density Function Theory (NLDFT). However, we observed in the literature a lack of systematic studies about the impacts that experimental uncertainty has on the determination of the pore size distribution (PSD). Thus, in this paper, we study the influence of errors related to experimental gaseous adsorption data on the solid characterization, showing the importance of the statistical analysis on the PSD of two idealized materials. The result suggests that this methodology has a strong dependence on the experimental uncertainty of the data used, i.e. the fit of adsorption isotherm is not a self-sufficient hypothesis to reconstruct the pore size distribution.


https://doi.org/10.1134/S001670291903011X

The paper presents data on the transformations of oil from seeps in the caldera of Uzon volcano under the effect of hydrous pyrolysis at a temperature of 350°C in an argon and oxygen atmosphere. The carbon and hydrogen isotopic-fractionation characteristics (IFC) are proved to reflect processes occurring in the organic matter at its hydrous pyrolysis in oxidizing and neutral environments. Similarities in configuration are detected between the carbon IFC of Uzon oil seeps, Bogachevskoe field, and the biota of hydrothermal springs. The hydrogen IFC are of more complicated form,

perhaps, because of exchange processes in the hydrothermal water. It is hypothesized that oil seeps in the interiors of the Uzon caldera can provide material for the origin of oil at the Bogachevskoe field. At the same time, it cannot be ruled out that hydrothermal water circulating in the caldera of Uzon volcano brings the material of the Bogachevskoe oil to the surface.

Shah, V., Zhao, X., Lundeen, R.A., Ingalls, A.E., Nicastro, D., Morris, R.M., 2019. Morphological plasticity in a sulfur-oxidizing marine bacterium from the SUP05 clade enhances dark carbon fixation. mBio 10, Article e00216-19.

http://mbio.asm.org/content/10/3/e00216-19.abstract

Abstract: Sulfur-oxidizing bacteria from the SUP05 clade are abundant in anoxic and oxygenated marine waters that appear to lack reduced sources of sulfur for cell growth. This raises questions about how these chemosynthetic bacteria survive across oxygen and sulfur gradients and how their mode of survival impacts the environment. Here, we use growth experiments, proteomics, and cryo-electron tomography to show that a SUP05 isolate, “Candidatus Thioglobus autotrophicus,” is amorphous in shape and several times larger and stores considerably more intracellular sulfur when it respires oxygen. We also show that these cells can use diverse sources of reduced organic and inorganic sulfur at submicromolar concentrations. Enhanced cell size, carbon content, and metabolic activity of the aerobic phenotype are likely facilitated by a stabilizing surface-layer (S-layer) and an uncharacterized form of FtsZ-less cell division that supports morphological plasticity. The additional sulfur storage provides an energy source that allows cells to continue metabolic activity when exogenous sulfur sources are not available. This metabolic flexibility leads to the production of more organic carbon in the ocean than is estimated based solely on their anaerobic phenotype.

Importance: Identifying shifts in microbial metabolism across redox gradients will improve efforts to model marine oxygen minimum zone (OMZ) ecosystems. Here, we show that aerobic morphology and metabolism increase cell size, sulfur storage capacity, and carbon fixation rates in “Ca. Thioglobus autotrophicus,” a chemosynthetic bacterium from the SUP05 clade that crosses oxic-anoxic boundaries.

Shahar, A., Driscoll, P., Weinberger, A., Cody, G., 2019. What makes a planet habitable? Science 364, 434-435.


The Milky Way Galaxy teems with planetary systems, most of which are unlike our own (1). It is tempting to assume that life can only originate on a planet that is similar to Earth, but different kinds of planets may be able to sustain Earth-like features that could be important for habitability. To focus the search for extraterrestrial life, scientists must assess which features of Earth are essential to the development and sustenance of life for billions of years and whether the formation of such planets is common. External effects such as stellar variability and orbital stability can affect habitability, but internal planetary processes that sustain a clement surface are essential to life; these processes are, however, difficult to characterize remotely. A combination of observations, experiments, and modeling are needed to understand the role of planetary interiors on habitability and guide the search for extraterrestrial life.

As exoplanet detection techniques improve, Earth-sized planets are likely to be found in the radiative habitable zone, that is, at distances from their host stars where they could have temperate (about 0° to 100°C) surface temperatures (2). This is important because to be habitable, a planet must be able to

buffer life from extreme (globally sterilizing) variations in temperature. Launched in 2018, NASA's Transiting Exoplanet Survey Satellite has the capability to find small planets in the habitable zone of nearby stars and measure their radii (3). Ground-based telescopes are providing masses for such planets. Their densities provide a first-order constraint on composition, although it is likely that several different possible compositions can be inferred from the same density (4). Planets with compositions that differ from those of planets in our Solar System have been largely ignored, even though a wide range of stellar compositions and planetary densities have been discovered. The discovery of life elsewhere in the Solar System, for example on an icy satellite, would also radically expand the types of planets that need to be considered. The James Webb Space Telescope, due to launch in 2021, will attempt to detect atmospheres of the most favorable planets for life, but detailed measurements of atmospheric composition will require future extremely large telescopes on the ground and in space.

Atmospheric Signatures of Life

Atmospheric composition will be the primary observable that could imply the presence of life (5). However, identifying a biological signature in a planet's atmosphere requires an understanding of the possible compositions of abiotic atmospheres. The presence of free oxygen or an atmosphere out of chemical equilibrium could be signatures of life processes, but neither is definitive because atmospheres change over time and are open systems that are subject to complex sources and sinks. Volcanic eruptions release gases from the planetary interior that are the product of melting and magma migration. Atmospheric weathering can draw down noncondensable species, like carbon dioxide from Earth's atmosphere, to the seafloor, where they can be recycled back into the interior at subduction zones. All these processes are linked to the bulk composition of the planet and will evolve over time.

It remains unclear, therefore, what inferences can be made about the planet's habitability from its atmosphere before understanding more about how the atmosphere is tied to the interior dynamics and evolution of the solid planet. To advance this understanding, exoplanet atmospheres, which give a valuable snapshot of the surface composition, should be combined with experimental and modeling constraints on the interactions between the atmosphere and interior over long time scales.

Interior Processes Sustaining Life

On Earth, the environment needed for life to exist and be sustained is rooted in the presence of a stable hydrosphere and atmosphere, which are controlled by the planet's bulk composition, interior structure, and dynamics. Plate tectonics plays a crucial role in the long-term moderation of the climate by cycling material between the surface and interior, thereby helping to stabilize the long-term climate, and by cooling the deep interior as hot plumes well up to the surface and cold plates drop down to the core-mantle boundary (6). This cooling drives convection and dynamo action (conversion of mechanical to electrical energy) in the liquid-iron outer core, which in turn produces the geomagnetic field that shields the atmosphere and protects the surface from the solar wind (see the figure).

Thus, Earth's interior maintains a stabilizing feedback between the hydrosphere, mantle, and core that is important for long-term habitability (7). Climate can also be affected by many external forces, such as stellar variability and orbital fluctuations, but fundamentally, a planet's composition dictates how it responds to these external forces. This prompts the question: Can Earth-like features be produced by planets with alternative compositions?

The Role of Planetary Composition

The bulk composition of a planet is inherited from the constituents of the protoplanetary disk in which the planet forms, as well as on the planetary building blocks and the mechanisms by which they accumulate to form a planet. Planet-hosting stars are known to span a range of compositions, with considerable variations in the ratios of abundant rocky planet materials such as silicon, magnesium, oxygen, carbon, and iron to hydrogen (8). Although the elemental building blocks of planets (such as oxygen, silicon, and iron) are universal, the relative abundances of elements and their processing during planet formation can dramatically alter the ratios of metal, rock, and ice that will set the internal structure of solid bodies (9). Compositional variations between exoplanets can arise in a protoplanetary disk when solids coagulate into planetesimals, when the temperature structure of the disk (and therefore locations where ice condenses) change over time, and if the formation of giant planets alters the feeding zones of later-forming rocky planets (10).

These compositional variations will likely produce a range of outcomes for rocky planets. Composition determines the internal material properties associated with heat and mass transport, like melting temperature, thermal and electrical conductivity, viscosity, and the abundance and partitioning of radiogenic isotopes. These properties control the heat budget and thermal evolution of a planet. The amount of water accreted during formation will affect the ocean volume at the surface, which in turn is influenced by water cycling between the surface and the deep Earth. The composition and subsequent partitioning of elements in the interior will determine the oxidation state of the mantle and therefore whether the species that are outgassed to the atmosphere are enriched or reduced (11). The physical parameters of high-pressure phases of rock that might exist in deep exoplanetary mantles control their water capacity, rate of heat transfer, likelihood of global convection, and rate of core cooling.

Therefore, the bulk composition and evolution of a planet depend on its formation pathway, accretionary environment, and interior dynamics. However, the implications of planetary composition for the interaction between the surface and interior are almost entirely unexplored.

How to Search for Habitability

The physical and chemical changes that a planet undergoes over billions of years—from the composition of the protoplanetary disk, to the differentiation of the planet and the giant impacts it may endure, to the start of plate tectonics and the generation of a magnetic field, and finally to liquid water on a clement surface—are all crucial for understanding habitability. The research needed to coherently investigate these processes cannot be done by scientists in a single discipline in isolation. Observations of stellar, disk, and planetesimal compositions must be combined with experimental studies of mineral physics and melting behavior to serve as inputs to planet formation and geodynamic models. In turn, the results of those modeling efforts will provide feedbacks into the observations and experiments by making predictions and identifying the compositions and material properties that are most important for habitability.

A better understanding of how the bulk composition and the interior of a planet influence habitability is needed to guide the search for the planets and stellar environments where life can thrive and be remotely detected. In the next decade, new extremely large ground- and space-based telescopes will measure the atmospheric compositions of rocky exoplanets and search for biosignatures in the gases (12). Humanity will build a library of information about the gaseous envelopes that comprise only a millionth of an exoplanet's mass. To put those measurements in context and to assess which planets may harbor life and sustain it for billions of years, scientists must understand how the bulk of the planet controls the evolution of a stable and clement atmosphere and surface environment. The heart of habitability lies in the planetary interior.

References

1. J. N. Winn, in Handbook of Exoplanets, H. J. Deeg, J. A. Belmonte, Eds. (Springer, 2018), Volume 1, pp. 1949–1966.

2. G. Anglada-Escudé et al., Nature 539, 437 (2016).3. L. Kaltenegger, J. Pepper, K. Stassun, K. Oelkers, 2019, ApJL, 874:L8 DOI: 10.3847/2041-

8213/ab0e8d.4. Zeng, D. D. Sasselov, S. B. Jacobsen, Astrophys. J. 819, 127 (2016).S. Seager, Science 340, 577 (2013).6. J..C.G. Walker, P.B. Hays, J.F. Kasting, J. Geophys. Res. 86 (C10), 9776 (1981).7. B. J. Foley, P. E. Driscoll, Geochem. Geophys. Geosyst. 17, 1885 (2016).8. J. M. Brewer, D. A. Fischer, Astrophys. J. Suppl. Ser. 237, 38 (2018).9. S. Ida, T. Yamamura, S. Okuzumi, Astron. Astrophys. 624, A28 (2019).10. J. E. Chambers, ApJ 825, 63 (2016).11. R. D. Wordsworth, L. K. Schaefer, R. A. Fischer, Astrophys. J. 155, 195 (2018).12. D. Clery, Science 358, 578 (2017).



An extensive monitoring, verification, and accounting (MVA) program was carried out from 2011 to 2016 as part of the Illinois Basin – Decatur Project (IBDP), a large-scale carbon capture and storage (CCS) demonstration project in Decatur, Illinois, USA. As part of the monitoring program, a near-surface monitoring network for soil gas was used to characterize the natural variability of CO2 and identify anomalies that could be associated with CO2 leakage in the vadose zone. In the fall of 2011, 21 permanent soil gas sampling nests were installed on-site and three nests were installed off-site as reference locations. Soil gas was collected from three depth intervals (15–30, 47–61, 107–122 cm) at each nest. Fixed gas (CO2, N2, O2, and light hydrocarbon) concentrations, stable carbon isotopic composition (δ13C), and radiocarbon (14C) content of CO2 in soil gas were monitored during the pre-injection, injection, and post-injection phases from 2011 to 2016. Both CO2 concentrations and carbon isotopic compositions showed large spatial and temporal variations; however, the relationships among CO2, N2, and O2 concentrations in soil gas indicated that these variations should be attributed to natural processes and not CO2 leakage. Soil CO2 concentrations responded to temperature and precipitation variations and increased with increasing soil depth. While 14C cannot be used to determine the occurrence of CO2 leakage at IBDP site due to the indistinctive signature between injected CO2 and soil gas CO2 , experiences at IBDP validated that δ13C can serve as an effective natural tracer at this site. Results from this project have value for future industrial CCS projects that plan to use soil gas monitoring techniques for site characterization and leakage detection.


https://doi.org/10.1007/s12594-019-1208-7

Extended Abstract of Monthly Scientific Lecture on 13-2-19

Sharov, G.N., Khadzhiev, S.N., 2019. On the inexhaustibility of oil reserves (Belozerov–Sharov–Minin Hypothesis). Petroleum Chemistry 59, 129-134.

https://doi.org/10.1134/S0965544119020154

The importance of oil as the most important mineral necessary for the progress of the world economy sharply raises the question of the exhaustion or inexhaustibility of its resources. The answer to this question is closely related to ideas about the origin of oil and hydrocarbons in general. In this article, the question of the origin of hydrocarbons is considered in the light of the proposed hypothesis of the origin and evolution of the Earth as an open system genetically related to the origin of the Universe. According to this hypothesis, the processes of gravitational collapse and the opposite process expansion, including that by an explosion, coexist in unlimited space, prevailing in one or another of its areas. The original substance (core) of the Earth is a fragment of the “dark matter” of an exploding neutron star. The planet Earth has an age corresponding to that of the Big Bang (about 15 billion years). The evolution of the Earth has two stages: pregeological and geological. The beginning of the geological stage of the Earth evolution is determined by the age of the most ancient artifacts in Earth’s crust. The core of the Earth emits excess neutrons, some of which decay immediately after separation from the nucleus to form a proton–electron pair or a hydrogen atom. A mixture of neutrons, protons, electrons, and nascent chemical elements is the “broth” in which chemical elements and their isotopes, as well as the simplest gases and complex compounds, are formed as a result of chaotic collisions. Neutron–proton–hydrogen (NPH) transformation, first formulated by I.M. Belozerov is the main process determining the development of the Earth. The formation of chemical elements and their isotopes occurs initially though the combination of two hydrogen nuclei into an α-particle, which is the helium nucleus and an integral part of the nuclei of chemical elements, primarily having a multiple of four. Due to the special features of their structure, hydrogen, oxygen, and carbon are of particular importance for the formation of complex compounds. In the process of synthesis of the simplest gases and complex elements, water, methane, carbon dioxide, hydrogen sulfide, and nitrous oxide are formed. The Belozerov–Sharov– Minin hypothesis proposed and this paper are not intended to intensify the discussion between advocates of the organic and inorganic hypotheses of oil origin. The paper calls for enhancing research, both theoretical and practical, aimed at increasing the source base of oil and other hydrocarbons by discovering new fields at various depths, both on land and in water areas. Oil is inexhaustible as long as neutron fluxes are emitted by the Earth core. The physical basis of the hypothesis under consideration is set out in the monograph by I.M. Belozerov “Nature through the Physicist Eyes” and in joint publications of the authors of the hypothesis, including data reported by other researchers. The geological rationale and the geological implications of the hypothesis are based on the results of research of the authors of this paper using information published by other researchers. References to the studies discussed in the above publications are not duplicated. On the basis of the hypothesis in question, particular recommendations on the formulation of forecasting and prospecting works can be given.

Shen, Y., Thiel, V., Suarez-Gonzalez, P., Rampen, S.W., Reitner, J., 2019. Sterol preservation in hypersaline microbial mats. Biogeosciences Discussions 2019, 1-28.


Microbial mats are self-sustaining benthic ecosystems composed of highly diverse microbial communities. It has been proposed that microbial mats were widespread in Proterozoic marine environments, prior to the emergence of bioturbating organisms at the Precambrian-Cambrian transition. One characteristic feature of Precambrian biomarker records is that steranes are typically absent or occur in very low concentrations. This has been explained by low eukaryotic source inputs, or degradation of primary produced sterols in benthic microbial mats (mat-seal effect). To better understand the preservational pathways of sterols in microbial mats we analysed freely extractable and carbonate-bound sterols as well as decalcified extraction residues in different layers of a recent calcifying mat (~ 1500 years) from the hypersaline Lake 2 on the island of Kiritimati, Central Pacific.

A variety of C27–C29 sterols and distinctive C31 4α-methylsterols (4α-methylgorgosterol and 4α-methylgorgostanol, biomarkers for dinoflagellates) were detected in both lipid pools. These sterols most likely originated from organisms living in the water column and the upper mat layers. This autochthonous biomass experienced progressive microbial transformation and degradation in the microbial mat, as reflected by a significant drop in total sterols concentrations, up to 98 %, in the deeper layers, and a concomitant decrease in total organic carbon. Carbonate-bound sterols were generally low in abundance, suggesting that incorporation into the mineral matrix does not play a major role for the preservation of eukaryotic sterols in this mat. Likewise, pyrolysis revealed that steroids (i.e., including sterenes, steranes and sterols), in contrast to hopanoids, were not sequestered into insoluble organic matter which may give rise to a further bias in the preservation of steroids vs. hopanoids, particularly in the later stages of burial. While these findings argue for a strong 'mat-seal effect' in the mat studied, they markedly differ from recent findings made for another microbial mat growing in the near-by hypersaline Lake 22 on the same island, where sterols showed no systematic decrease with depth. The observed discrepancies in the taphonomic pathways of sterols in microbial mats from Kiritimati may be linked to multiple biotic and abiotic factors including salinity and periods of subaerial exposure, implying that caution has to be exercised in the interpretation of sterols distributions in modern and ancient microbial mat settings.

Shetty, P.P., Zhang, R., Haire, B.T., Smith, C.S., Kenny, L.M., Wu, T., Subramani, V., Morrison, J.J., Quayle, P., Yeates, S., Braun, P.V., Krogstad, J.A., 2019. Effect of surface chemistry and roughness on the high-temperature deposition of a model asphaltene. Energy & Fuels 33, 4104-4114.


Fouling of processing units because of asphaltene deposition is a common phenomenon that interrupts the operation of oil refineries. In this study, the deposition behavior of a model archipelago asphaltene in the temperature range of 150 to 350 °C was investigated. For a fixed surface chemistry, the differences in deposit chemistry with fouling temperature is a function of the thermochemical properties of the model asphaltene. Under static high-pressure and high-temperature fouling conditions, both surface roughness and chemistry play an important role in asphaltene deposition. Rough surfaces are shown to develop larger deposits because of less restrictive physical barriers to inhibit deposit growth. Passivating the surface with an alumina chemistry significantly reduces the impact of surface roughness, as well as the total amount of deposition. This beneficial effect of using a protective alumina chemistry is attributed to its high thermal stability and low diffusivity that inhibit the uncontrolled formation of thiolate and sulfide deposits that are found on unpassivated steels. Instead, alumina modifies the surface reaction to a self-limiting chemisorption and oxidation process that produces thin sulfate deposits at the surface. With further consideration to the reactive species present in solution, the findings of this study may be extended to determine suitable surface conditions that mitigate asphaltene fouling.

Shibini Mol, P.A., Sujatha, C.H., Krishnan, A., Deepak, K., Sruthy Mol, P.P., Priyanka, B.R., Dhanya, P.V., 2019. Spatial distribution of organic geochemical record in the core sediments along the prominent zones of Central Kerala, India. Environmental Forensics 20, 92-105.

https://doi.org/10.1080/15275922.2019.1566294

The study investigated the origin, quality, composition, and trophic state of sedimentary organic matter (SOM) in core samples collected from three zones (Munambam, Vypin, Chettuva) of Central Kerala, India. The SOM exhibited enhanced levels for carbohydrate (CHO) followed by protein (PRT) and lipid (LPD); and phytopigment in the sediment followed the trend: Pheophytin (Pheo) >

Carotenoid (carotend) > Chlorophyll-a (Chl-a) > Chlorophyll-b (Chl-b) > Chlorophyll-c (Chl-c). The low PRT: CHO ratio indicated a large amount of nonliving or aged organic matter in the sedimentary environment. Whereas the low Chl-a: Pheo ratio interprets the abundance of dead plant materials in the sediments. Correlation matrix showed strong association between organic matter and clay fraction of sediment. Furthermore, the strong interrelationships between biochemical components and chloropigments in all the zones suggested that SOM is strictly connected to phytodetritus deposition. Vypin zone near Vallarpadam Container Terminal revealed the presence of high biopolymeric carbon content. Besides, the PRT: CHO > 1 reflected the eutrophic condition at the same site but the low PRT: CHO ratio in the remaining stations displays the oligotrophic nature.

Sholes, S.F., Krissansen-Totton, J., Catling, D.C., 2019. A maximum subsurface biomass on Mars from untapped free energy: CO and H2 as potential antibiosignatures. Astrobiology 19, 655-668.


Whether extant life exists in the martian subsurface is an open question. High concentrations of photochemically produced CO and H2 in the otherwise oxidizing martian atmosphere represent untapped sources of biologically useful free energy. These out-of-equilibrium species diffuse into the regolith, so subsurface microbes could use them as a source of energy and carbon. Indeed, CO oxidation and methanogenesis are relatively simple and evolutionarily ancient metabolisms on Earth. Consequently, assuming CO- or H2-consuming metabolisms would evolve on Mars, the persistence of CO and H2 in the martian atmosphere sets limits on subsurface metabolic activity. In this study, we constrain such maximum subsurface metabolic activity on Mars using a one-dimensional photochemical model with a hypothetical global biological sink on atmospheric CO and H2. We increase the biological sink until the modeled atmospheric composition diverges from observed abundances. We find maximum biological downward subsurface sinks of 1.5 × 108 molecules/(cm2·s) for CO and 1.9 × 108 molecules/(cm2·s1) for H2. These convert to a maximum metabolizing biomass of ≲1027 cells or ≤2 × 1011 kg, equivalent to ≤10−4–10−5 of Earth's biomass, depending on the terrestrial estimate. Diffusion calculations suggest that this upper biomass limit applies to the top few kilometers of the martian crust in communication with the atmosphere at low to mid-latitudes. This biomass limit is more robust than previous estimates because we test multiple possible chemoautotrophic ecosystems over a broad parameter space of tunable model variables using an updated photochemical model with precise atmospheric concentrations and uncertainties from Curiosity. Our results of sparse or absent life in the martian subsurface also demonstrate how the atmospheric redox pairs of CO-O2 and H2-O2 may constitute antibiosignatures, which may be relevant to excluding life on exoplanets.

Silva, T.R., Tavares, R.S.N., Canela-Garayoa, R., Eras, J., Rodrigues, M.V.N., Neri-Numa, I.A., Pastore, G.M., Rosa, L.H., Schultz, J.A.A., Debonsi, H.M., Cordeiro, L.R.G., Oliveira, V.M., 2019. Chemical characterization and biotechnological applicability of pigments isolated from Antarctic bacteria. Marine Biotechnology 21, 416-429.

https://doi.org/10.1007/s10126-019-09892-z

Considering the global trend in the search for alternative natural compounds with antioxidant and sun protection factor (SPF) boosting properties, bacterial carotenoids represent an opportunity for exploring pigments of natural origin which possess high antioxidant activity, lower toxicity, no residues, and no environmental risk and are readily decomposable. In this work, three pigmented bacteria from the Antarctic continent, named Arthrobacter agilis 50cyt, Zobellia laminarie 465, and Arthrobacter psychrochitiniphilus 366, were able to withstand UV-B and UV-C radiation. The

pigments were extracted and tested for UV absorption, antioxidant capacity, photostability, and phototoxicity profile in murine fibroblasts (3T3 NRU PT–OECD TG 432) to evaluate their further potential use as UV filters. Furthermore, the pigments were identified by ultra-high-performance liquid chromatography–photodiode array detector–mass spectrometry (UPLC-PDA-MS/MS). The results showed that all pigments presented a very high antioxidant activity and good stability under exposure to UV light. However, except for a fraction of the A. agilis 50cyt pigment, they were shown to be phototoxic. A total of 18 different carotenoids were identified from 23 that were separated on a C18 column. The C50 carotenes bacterioruberin and decaprenoxanthin (including its variations) were confirmed for A. agilis 50cyt and A. psychrochitiniphilus 366, respectively. All-trans-bacterioruberin was identified as the pigment that did not express phototoxic activity in the 3T3 NRU PT assay (MPE < 0.1). Zeaxanthin, β-cryptoxanthin, β-carotene, and phytoene were detected in Z. laminarie 465. In conclusion, carotenoids identified in this work from Antarctic bacteria open perspectives for their further biotechnological application towards a more sustainable and environmentally friendly way of pigment exploitation.

Simon, J., Rédei, C., Felinger, A., 2019. The use of alteration analysis in supercritical fluid chromatography to monitor changes in a series of chromatograms. Journal of Chromatography A 1596, 217-225.


Two-dimensional correlation analysis (2DCOR) is a unique chemometric method introduced in spectroscopy which became successful in a wide range of analytical fields. It was applied in chromatography as well but has not gained wide-spread popularity. In our previous work, we introduced an alternative method, Alteration Analysis (ALA), which is built upon the basic properties of 2DCOR, but it is fine-tuned for chromatographic applications and can be used on higher dimensional data sets as well. We explored its merits through computer generated examples. In this study, we present the application of ALA to two various data-sets in chromatography. First, we used a series of samples where the concentrations of the compounds were adjusted according to the changes we studied in our previous in-silico experiments.

We compared the alteration maps from the computer generated and measured sources. The results demonstrated that ALA can provide the same properties from measured data as laid down in theory.

The second one is a test concerning the effect of sample solvent composition in supercritical fluid chromatography (SFC). ALA maps show the influence of increasing methanol concentration on the peak location and shape of compounds in the chromatogram.

With these two examples, we demonstrate that ALA can be used not only in theory, but it has also practical potentials and importance.

Sivaram, C., Arun, K., Kiren, O.V., 2019. Alternative standard frequencies for interstellar communication. International Journal of Astrobiology 18, 209-210.

https://doi.org/10.1017/S1473550417000350

The 21 cm hydrogen line is considered a favourable frequency by the SETI programme in their search for signals from potential extraterrestrial (ET) civilizations. The Pioneer plaque, attached to the Pioneer 10 and Pioneer 11 spacecraft, portrays the hyperfine transition of neutral hydrogen and used the wavelength as a standard scale of measurement. Although this line would be universally recognized and is a suitable wavelength to look for radio signals from ETs, the presence of ubiquitous

radiation from galactic hydrogen could make searches a little difficult. In this paper, we suggest several alternate standard frequencies, which are free of interference from atomic or molecular sources and is independent of any bias.

Sivaram, C., Arun, K., Kiren, O.V., 2019. Bioenergetics and stellar luminosities. International Journal of Astrobiology 18, 211-212.

https://doi.org/10.1017/S1473550417000386

We draw attention to a curious coincidence wherein the most (steadily emitting) luminous objects in the Universe from stellar X-ray sources to ultra-luminous quasars and Ultra Luminous Infrared Galaxies, steadily emit a power per unit mass, which is just the same value as the maximal metabolic rate in (warm-blooded) bio-organisms.

Smeaton, C., Cui, X., Bianchi, T.S., Cage, A.G., Howe, J.A., Austin, W.E.N., 2019. The Holocene evolution of a sedimentary carbon store in a mid latitude fjord. Biogeosciences Discussions 2019, 1-31.


Fjord sediments are recognized as hotspots for the burial and storage of organic carbon, yet little is known about what drives the formation of these coastal carbon stores and how this has altered over time. Here we show that fjords can act as sustained hotspots for carbon burial and storage over Holocene timescales. Further we investigate the role of North Atlantic climate and humans in the evolution of a coastal carbon store using sediment records from a temperate Scottish fjord. Our findings indicate that climate and anthropogenic activity have independently driven increases in terrestrial carbon to the marine environment. When both these drivers were coupled, the terrestrial response was pronounced and the relative proportion of terrestrial OC in the marine sediments increases from 5 % up to 70 %. We hypothesize that sustained human disturbance through the late Holocene sensitized the catchment to abrupt climate reorganizations. The results highlight the importance of fjords for carbon burial and the significance of terrestrial carbon subsidy to the long-term carbon store.

Smets, T., Verbeeck, N., Claesen, M., Asperger, A., Griffioen, G., Tousseyn, T., Waelput, W., Waelkens, E., De Moor, B., 2019. Evaluation of distance metrics and spatial autocorrelation in uniform manifold approximation and projection applied to mass spectrometry imaging data. Analytical Chemistry 91, 5706-5714.


In this work, uniform manifold approximation and projection (UMAP) is applied for nonlinear dimensionality reduction and visualization of mass spectrometry imaging (MSI) data. We evaluate the performance of the UMAP algorithm on MSI data sets acquired in mouse pancreas and human lymphoma samples and compare it to those of principal component analysis (PCA), t-distributed stochastic neighbor embedding (t-SNE), and the Barnes–Hut (BH) approximation of t-SNE. Furthermore, we compare different distance metrics in (BH) t-SNE and UMAP and propose the use of spatial autocorrelation as a means of comparing the resulting low-dimensional embeddings. The results indicate that UMAP is competitive with t-SNE in terms of visualization and is well-suited for the dimensionality reduction of large (>100 000 pixels) MSI data sets. With an almost fourfold decrease in runtime, it is more scalable in comparison with the current state-of-the-art: t-SNE or the

Barnes–Hut approximation of t-SNE. In what seems to be the first application of UMAP to MSI data, we assess the value of applying alternative distance metrics, such as the correlation, cosine, and the Chebyshev metric, in contrast to the traditionally used Euclidean distance metric. Furthermore, we propose “histomatch” as an additional custom distance metric for the analysis of MSI data.

Smirnov, M.B., Vanyukova, N.A., 2019. Distribution patterns of the main structural group parameters of crude oils from the Lena–Tunguska oil-and-gas basin by 1H NMR data. Petroleum Chemistry 59, 135-142.

https://doi.org/10.1134/S0965544119020178

The distribution of the 1H NMR-measurable characteristics of the structural-group composition of crude oils from the Lena–Tunguska basin has been revealed. It has been shown that some distributions are fairly close to the normal one, while others greatly differ from it and are asymmetric. These oils differ from Volga–Urals and Western Siberia oils by a significantly lower aromatics content and a high concentration of radiogenic unsaturated hydrocarbons. The average degree of substitution of aromatics in them is higher than in Western Siberia oils; the distribution maximum for the parameter characterizing this value falls in the region between the two distribution maxima for the Volga–Urals oil. The distribution of the Har,2+/Har,1 ratio is about the same as in the Volga–Urals and Western Siberia oils. A significant difference in the composition between the oils of the Baikit anteclise and the Nepa–Botuoba anteclise has been found.

Soares, A.R.A., Berggren, M., 2019. Indirect link between riverine dissolved organic matter and bacterioplankton respiration in a boreal estuary. Marine Environmental Research 148, 39-45.


Increasing loading of terrestrially derived dissolved organic matter tends to enhance bacterioplankton respiration (BR) in boreal estuaries, but knowledge on the mechanisms behind this effect is not complete. We determined the stable isotopic signature of the reactive estuarine dissolved organic carbon (DOC) in the Öre estuary (Baltic Sea) by using the Keeling plot method. The δ13C ratio of the estuarine labile DOC varied from −26.0‰ to −18.7‰ with most values resembling those typical for DOC of coastal phytoplanktonic origin (−18 to −24‰), while being distinctly higher than those of DOC from terrestrial sources (−28‰ to −27‰). Furthermore, the δ13C of the respired carbon was positively correlated to DOC concentrations, indicating that carbon of marine origin increasingly dominated the reactive substrates when input of organic matter into the estuary became higher. This suggests that riverine organic matter mainly affects BR indirectly, by providing nutrients that stimulate the production of phytoplankton-derived reactive DOC in the estuary. Thus, riverine derived DOC per se may not be as important for coastal CO2 emissions as previously thought.



Biodegradation is important for the fate of oil spilled in marine environments, yet parameterization of biodegradation varies across oil spill models, which usually apply constant first-order decay rates to multiple pseudo-components describing an oil. To understand the influence of model parameterization on the fate of subsurface oil droplets, we reviewed existing algorithms and rates and

conducted a model sensitivity study. Droplets were simulated from a blowout at 2000 m depth and were either treated with sub-surface dispersant injection (2% dispersant to oil ratio) or untreated. The most important factor affecting oil fate was the size of the droplets, with biodegradation contributing substantially to the fate of droplets ≤0.5 mm. Oil types, which were similar, had limited influence on simulated oil fate. Model results suggest that knowledge of droplet sizes and improved estimation of pseudo-component biodegradation rates and lag times would enhance prediction of the fate and transport of subsurface oil.

Song, B., Tang, J., Zhen, M., Liu, X., 2019. Effect of rhamnolipids on enhanced anaerobic degradation of petroleum hydrocarbons in nitrate and sulfate sediments. Science of The Total Environment 678, 438-447.


Anaerobic degradation of petroleum hydrocarbons (PH) is an important process in contaminated environment. The application of rhamnolipids in anaerobic degradation of PH was not extensively studied and inconclusive. This study explored the combined effect of rhamnolipids and electron acceptors on the anaerobic degradation process of total petroleum hydrocarbons (TPH) in sediment from an oil field. The results indicated that rhamnolipids decreased the surface tension of the medium and increased the desorption of TPH from the sediment. After 10-wk culture, the maximum degradation rate of TPH in nitrate and sulfate condition was found to be 32.2% and 24.0%, respectively, with rhamnolipids concentration of 150 mg/L. The addition of 45 and 150 mg/L rhamnolipids increased the degradation rate of TPH but the promotion effect was weakened in the treatment with 450 mg/L rhamnolipids. The copy number of two degradation genes (1-methylalkyl) succinate synthase gene (masD) and 6-oxocyclohex-1-ene-1-carbonyl-CoA hydrolase gene (bamA) increased with incubation time and showed higher copy numbers in treatments with 45 and 150 mg/L rhamnolipids. In the first week, with the increase of rhamnolipids concentration, the copy number of 16S rDNA increased rapidly and the concentration of electron receptors decreased correspondingly. Moreover, no nitrate was detected in treatments of nitrate with 450 mg/L rhamnolipids after the first week. Microbial community structure analysis result showed that Thiobacillus was the dominant bacteria in all treatments with nitrate as electron acceptor and its proportion gradually decreased with the increase of rhamnolipids concentration. The addition of rhamnolipids changed the subdominant bacteria in the treatments with nitrate as electron acceptor. Methanothrix was the dominant archaea in all treatments with rhamnolipids content of lower than 45 mg/L. When the rhamnolipids concentration increased, the dominant archaea changed to Methanogenium or Methanobacterium. In conclusion, suitable concentrations of rhamnolipids could promote the anaerobic degradation of PH in the sediment.



To precisely quantify pore space and organic matter (OM) from two-dimensional scanning electron microscope (SEM) images, an efficient and consistent workflow using adaptive local thresholding, Otsu thresholding and Image Calculator are presented. It can offer an automated segmentation of pore space and OM, then differentiates the porosity hosted by OM and minerals. The workflow is demonstrated on a widely distributed set of core samples from Mahantango and Marcellus shale units of the Appalachian basin. The vitrinite reflectance of these samples ranges from 1.36% to 2.89%,

covering a spectrum of thermal maturity. Organic matter abundance and mineralogy also vary significantly. The results are compared with routine rock property tests, such as helium porosimeter (Gas Research Institute method), and total OM. The proposed workflow improves quantitative determination of porosity above a certain pore size and OM in shale samples. Advantages of this workflow include improved consistency and speed of analysis of SEM images of shale samples at the nanoscale.



The pore structure of coal reservoirs determines the reserves of coalbed methane, and the gas permeability determines the level of the production capacity. In this study, the SEM images of coal samples were analyzed by various means. First, the grayscale threshold of binarization of the coal sample image is determined by a suitable algorithm. Comparing several different algorithms, the porosity based on Yen algorithm is closer to the results of vacuum saturation method and nuclear magnetic resonance (NMR) (8.35% vs. 7.51% vs. 8.92%). Further, the pore size distribution (PSD) of the coal sample is obtained according to discrete and continuous algorithms. By comparing the SEM results with the NMR results, it is found that the calculation results based on the continuous algorithm (CPSD) are better than the discrete algorithm (DPSD) and closer to the NMR results. For the effect of scale, we found that the image resolution has a certain influence on the minimum pore size characterized, such as sample C1: 0.29 μm ( × 1000) vs 0.58um ( × 500). At high resolution, more micro-pores are observed. Further, we predict the permeability of coal samples based on SEM images. It is found that the calculation results based on the continuous algorithm and the Hagen–Poiseuille equation are closer to the measured values (e.g., 16.97 (DPSD) vs. 0.45(CPSD) vs. 0.59 mD (Lab), sample C2, magnification of × 1000). In general, this method can effectively evaluate the pore structure characteristics and permeability of coal samples.

Sørensen, L., Hansen, B.H., Farkas, J., Donald, C.E., Robson, W.J., Tonkin, A., Meier, S., Rowland, S.J., 2019. Accumulation and toxicity of monoaromatic petroleum hydrocarbons in early life stages of cod and haddock. Environmental Pollution 251, 212-220.


A multitude of recent studies have documented the detrimental effects of crude oil exposure on early life stages of fish, including larvae and embryos. While polycyclic aromatic hydrocarbons (PAHs), particularly alkyl PAHs, are often considered the main cause of observed toxic effects, other crude oil derived organic compounds are usually overlooked. In the current study, comprehensive two-dimensional gas chromatography coupled to mass spectrometry was applied to investigate the body burden of a wide range of petrogenic compounds in Atlantic haddock (Melanogrammus aeglefinus) and cod (Gadus morhua) embryos that had been exposed to sublethal doses of dispersed crude oil. Several groups of alkylated monoaromatic compounds (e.g. alkyl tetralins, indanes and alkyl benzenes), as well as highly alkylated PAHs, were found to accumulate in the fish embryos upon crude oil exposure. To investigate the toxicity of the monoaromatic compounds, two models (1-isopropyl-4-methyltetralin and 1-isopropyl-4-methylindane) were synthesized and shown to bioaccumulate and cause delayed hatching in developing embryos. Minor developmental effects, including craniofacial and jaw deformations and pericardial edemas, were also observed at the highest studied concentrations of the alkylindane.

Sovová, K., Spesyvyi, A., Bursová, M., Pásztor, P., Kubišta, J., Shestivska, V., Španěl, P., 2019. Time-integrated thermal desorption for quantitative SIFT-MS analyses of atmospheric monoterpenes. Analytical and Bioanalytical Chemistry 411, 2997-3007.

https://doi.org/10.1007/s00216-019-01782-6

A new time-integrated thermal desorption technique has been developed that can be used with selected ion flow tube mass spectrometry, TI-TD/SIFT-MS, for off-line quantitative analyses of VOCs accumulated onto sorbents. Using a slow desorption temperature ramp, the absolute amounts of desorbed compounds can be quantified in real time by SIFT-MS and constitutional isomers can be separated. To facilitate application of this technique to environmental atmospheric monitoring, method parameters were optimised for quantification of the three common atmospheric monoterpenes: β-pinene, R-limonene and 3-carene. Three sorbent types, Tenax TA, Tenax GR and Porapak Q, were tested under 26 different desorption conditions determined by the “design of experiment”, DOE, systematic approach. The optimal combination of type of sorbent, bed length, sampling flow rate, sample volume and the initial desorption temperature was determined from the experimental results by ANOVA. It was found that Porapak Q exhibited better efficiency of sample collection and further extraction for total monoterpene concentration measurements. On the other hand, Tenax GR or TA enabled separation of all three monoterpenes. The results of this laboratory study were tested with the sample accumulated from a branch of a Pinus nigra tree.

Spencer, C.J., Partin, C.A., Kirkland, C.L., Raub, T.D., Liebmann, J., Stern, R.A., 2019. Paleoproterozoic increase in zircon δ18O driven by rapid emergence of continental crust. Geochimica et Cosmochimica Acta 257, 16-25.


Numerous geologic proxies for Earth system processes track dramatic changes at the atmosphere-lithosphere or atmosphere-ocean interface during the early Paleoproterozoic Era. The presence of a geodynamic driver for these changes and how this might have affected the deeper lithosphere is more cryptic. Here we present temporally constrained δ18O and εHf in detrital zircon from Paleoproterozoic sedimentary successions in Western Australia and Canada that chart a rapid change in the oxygen isotopic composition from <7.5‰ prior to Great Oxidation Event (GOE) to 9–11‰ by ∼2.3 Ga. Intriguingly, we show that the timing of this zircon δ18O isotopic shift directly coincides with the GOE and the rapid development of continental freeboard evidenced by the shift from predominantly subaqueous to subaerial large igneous provinces and a rapid decrease in Δ17O in shale. Importantly, no correlation exists between zircon δ18O and εHf or to known periods of enhanced tectonic reworking of sedimentary material (e.g. ∼2.3–2.2 Ga tectono-magmatic lull). We propose that the development of continental freeboard led to the appearance of an isotopically distinct sedimentary reservoir with high δ18O that was incorporated into subduction zone magmas. The sedimentary contamination of subduction zone magmas led to a globally rapid change in average continental composition as recorded by δ18O in zircon grains.

Stal, L.J., Bolhuis, H., Cretoiu, M.S., 2019. Phototrophic marine benthic microbiomes: the ecophysiology of these biological entities. Environmental Microbiology 21, 1529-1551.

https://doi.org/10.1111/1462-2920.14494

Phototrophic biofilms are multispecies, self-sustaining and largely closed microbial ecosystems. They form macroscopic structures such as microbial mats and stromatolites. These sunlight-driven consortia consist of a number of functional groups of microorganisms that recycle the elements internally. Particularly, the sulfur cycle is discussed in more detail as this is fundamental to marine benthic microbial communities and because recently exciting new insights have been obtained. The cycling of elements demands a tight tuning of the various metabolic processes and require cooperation between the different groups of microorganisms. This is likely achieved through cell-to-cell communication and a biological clock. Biofilms may be considered as a macroscopic biological entity with its own physiology. We review the various components of some marine phototrophic biofilms and discuss their roles in the system. The importance of extracellular polymeric substances (EPS) as the matrix for biofilm metabolism and as substrate for biofilm microorganisms is discussed. We particularly assess the importance of extracellular DNA, horizontal gene transfer and viruses for the generation of genetic diversity and innovation, and for rendering resilience to external forcing to these biological entities.



Phenolic compounds occur in a variety of plants and can be used as model compounds for investigating the fate of organic wastewater, lignin, or soil organic matter in the environment. The aim of this study was to better understand and differentiate mechanisms associated with photo- and biodegradation of tyrosol, vanillin, vanillic acid, and coumaric acid in soil. In a 29 d incubation experiment, soil spiked with these phenolic compounds was either subjected to UV irradiation under sterile conditions or to the native soil microbial community in the dark. Changes in the isotopic composition (δ13C) of phenolic compounds were determined by gas chromatography–isotope ratio mass spectrometry and complemented by concentration measurements. Phospholipid-derived fatty acid and ergosterol biomarkers together with soil water repellency measurements provided information on soil microbial and physical properties. Biodegradation followed pseudo-first-order dissipation kinetics, enriched remaining phenolic compounds in 13C, and was associated with increased fungal rather than bacterial biomarkers. Growing mycelia rendered the soil slightly water repellent. High sample variation limited the reliable estimation of apparent kinetic isotope effects (AKIEs) to tyrosol. The AKIE of tyrosol biodegradation was 1.007 ± 0.002. Photooxidation kinetics were of pseudo-zero- or first-order with an AKIE of 1.02 ± 0.01 for tyrosol, suggesting a hydroxyl-radical mediated degradation process. Further research needs to address δ13C variation among sample replicates potentially originating from heterogeneous reaction spaces in soil. Here, nuclear magnetic resonance or nanoscopic imaging could help to better understand the distribution of organic compounds and their transformation in the soil matrix.

Steinmuller, H.E., Chambers, L.G., 2019. Characterization of coastal wetland soil organic matter: Implications for wetland submergence. Science of The Total Environment 677, 648-659.


High rates of relative sea level rise can cause coastal wetland submergence, jeopardizing the stability of soil organic matter (SOM) sequestered within wetlands. Following submergence, SOM can be lost through mineralization, exported into the coastal ocean, or reburied within adjacent subtidal sediments. By combining measures of soil physicochemical properties, microbial community

abundance, organic carbon fractionation, and stable isotope signatures, this study characterized subsurface SOM within a coastal wetland to inform its potential fate under altered environmental conditions. Nine soil cores were collected to a depth of 150 cm from a wetland currently experiencing rapid erosion and submergence within Barataria Bay, LA (USA), and were sectioned into 10 cm intervals. Each soil segment was analyzed to determine total carbon (C), nitrogen (N), phosphorus (P), and stable isotope (δ13C and δ15N) content, as well as extractable ammonium (NH4

+), nitrate (NO3

−), and soluble reactive phosphorus (SRP). Extractable NH4+ and SRP concentrations increased 7× and 11×, respectively, between 0–10 cm and 130–140 cm. Through quantitative PCR, number of gene copies of bacteria and sulfate reduction genes were found to decrease with depth while there was no change in number of gene copies of archaea. This study also demonstrated only small decreases in labile: refractory C ratios with depth; by combining δ15N data with labile:refractory C ratios and no observed change in C:N ratios with depth, we inferred the presence of minimally processed organic material within deep soils and high nutrient availability, challenging the applicability of the traditional theory of selective preservation and decreased soil quality with depth. As wetland submergence progresses and soils are exposed to oxygenated seawater, this relatively labile SOM and bioavailable N and P stored at depth has the potential for rapid mineralization and/or export into the coastal zone.

Stevenson, D.S., Large, S., 2019. Evolutionary exobiology: towards the qualitative assessment of biological potential on exoplanets. International Journal of Astrobiology 18, 204-208.

https://doi.org/10.1017/S1473550417000349

A planet may be defined as habitable if it has an atmosphere and is warm enough to support the existence of liquid water on its surface. Such a world has the basic set of conditions that allow it to develop life similar to ours, which is carbon-based and has water as its universal solvent. While this definition is suitably vague to allow a fairly broad range of possibilities, it does not address the question as to whether any life that does form will become either complex or intelligent. In this paper, we seek to synthesize a qualitative definition of which subset of these ‘habitable worlds’ might develop more complex and interesting life forms. We identify two key principles in determining the capacity of life to breach certain transitions on route to developing intelligence. The first is the number of potential niches a planet provides. Secondly, the complexity of life will reflect the information density of its environment, which in turn can be approximated by the number of available niches. We seek to use these criteria to begin the process of placing the evolution of terrestrial life in a mathematical framework based on environmental information content. This is currently testable on Earth and will have clear application to the worlds that we are only beginning to discover. Our model links the development of complex life to the physical properties of the planet, something which is currently lacking in all evolutionary theory.

Stevenson, M.A., Abbott, G.D., 2019. Exploring the composition of macromolecular organic matter in Arctic Ocean sediments under a changing sea ice gradient. Journal of Analytical and Applied Pyrolysis 140, 102-111.


Arctic sea ice has been affected by climate change, leading to reductions in summer sea ice extent over the past few decades, impacting nutrient dynamics, ocean temperature fluxes and the biological communities present in the ocean. Marine organic matter is a complex mixture of differentially degraded terrestrial and marine organisms from a range of sources and time periods. In this study pyrolysis-gas chromatography-mass spectrometry (Py-GC–MS) has been used to quantify the

solvent-insoluble component of marine organic matter in surface sediments to gain a more holistic understanding of the macromolecular composition at five stations along a south to north transect in the Arctic Barents Sea, east of Svalbard (depths 288–334 m.b.s.l). Two methods were compared to identify the effectiveness of rapid screening, in contrast to grouping similar pyrolysis products. There were changes in macromolecular composition of marine surface sediments across the S-N transect using both methods, highlighting the varying benthic and pelagic communities north of the Polar Front and across the variable sea ice margin, corresponding to differing biological communities (e.g. fish, phytoplankton, ice algae, zooplankton). All five stations across the changing sea ice transect were interpreted as having primarily marine surface sediment macromolecular signatures, given their locations far from major terrestrial inputs and the more subtle changes when compared with previous investigations on the East Siberian Artic shelf. Fluctuations in macromolecular compositions across the transect included increasing N-containing compounds (including pyridines) and n-alkene/n-alkane doublet pyrolysis products from sediments collected in stations with the greatest average ice cover. If the future position of the Polar Front moves northwards then deposition of labile organic matter which appears to be efficiently processed will move further north, meaning greater deposition of organic carbon under areas of open ocean. Future research needs to understand how this OC will be buried and if it is regionally significant, given anticipated weakening stratification and a more Atlantic influenced northern Barents Sea.

Steyer, D.J., Kennedy, R.T., 2019. High-throughput nanoelectrospray ionization-mass spectrometry analysis of microfluidic droplet samples. Analytical Chemistry 91, 6645-6651.


Droplet microfluidics enables high-throughput manipulation of fL−μL volume samples. Methods implemented for the chemical analysis of microfluidic droplets have been limited in scope, leaving some applications of droplet microfluidics difficult to perform or out of reach entirely. Nanoelectrospray ionization-mass spectrometry (nESI-MS) is an attractive approach for droplet analysis, because it allows rapid, label-free, information-rich analysis with high mass sensitivity and resistance to matrix effects. Previous proof-of-concept systems for the nESI-MS analysis of droplets have been limited by the microfluidics used so that stable, long-term operation needed for high-throughput applications has not been demonstrated. We describe a platform for the stable analysis of microfluidic droplet samples by nESI-MS. Continuous infusion of droplets to an nESI emitter was demonstrated for as long as 2.5 h, corresponding to analysis of over 20 000 samples. Stable signal was observed for droplets as small as 65 pL and for throughputs as high as 10 droplets/s. A linear-concentration-based response and sample-to-sample carryover of <3% were also shown. The system is demonstrated for measuring products of in-droplet enzymatic reactions.

Stolper, D.A., Bucholz, C.E., 2019. Neoproterozoic to early Phanerozoic rise in island arc redox state due to deep ocean oxygenation and increased marine sulfate levels. Proceedings of the National Academy of Sciences 116, 8746-8755.


Significance: Igneous island arc rocks are more oxidized than midocean-ridge basalts. Whether this originates from an oxidized mantle source or during differentiation or eruption is debated. Newly compiled Fe3+/ΣFe and V/Sc ratios presented here indicate that island arc rocks became more oxidized 800–400 Ma. We attribute this increase in the redox state of island arc rocks to the oxidation of their mantle source from subduction of oxidized oceanic crust following deep-ocean oxygenation and increased marine sulfate concentrations over the same time interval. This provides evidence that

the oxidized nature of modern island arc magmas is due to an oxidized mantle source and represents a rare example of a change in the surface biogeochemistry influencing the igneous rock record.

Abstract: A rise in atmospheric O2 levels between 800 and 400 Ma is thought to have oxygenated the deep oceans, ushered in modern biogeochemical cycles, and led to the diversification of animals. Over the same time interval, marine sulfate concentrations are also thought to have increased to near-modern levels. We present compiled data that indicate Phanerozoic island arc igneous rocks are more oxidized (Fe3+/ΣFe ratios are elevated by 0.12) vs. Precambrian equivalents. We propose this elevation is due to increases in deep-ocean O2 and marine sulfate concentrations between 800 and 400 Ma, which oxidized oceanic crust on the seafloor. Once subducted, this material oxidized the subarc mantle, increasing the redox state of island arc parental melts, and thus igneous island arc rocks. We test this using independently compiled V/Sc ratios, which are also an igneous oxybarometer. Average V/Sc ratios of Phanerozoic island arc rocks are elevated (by +1.1) compared with Precambrian equivalents, consistent with our proposal for an increase in the redox state of the subarc mantle between 800 and 400 Ma based on Fe3+/ΣFe ratios. This work provides evidence that the more oxidized nature of island arc vs. midocean-ridge basalts is related to the subduction of material oxidized at the Earth’s surface to the subarc mantle. It also indicates that the rise of atmospheric O2 and marine sulfate to near-modern levels by the late Paleozoic influenced not only surface biogeochemical cycles and animal diversification but also influenced the redox state of island arc rocks, which are building blocks of continental crust.

Stukel, M.R., Kelly, T.B., Aluwihare, L.I., Barbeau, K.A., Goericke, R., Krause, J.W., Landry, M.R., Ohman, M.D., 2019. The Carbon:234Thorium ratios of sinking particles in the California current ecosystem 1: relationships with plankton ecosystem dynamics. Marine Chemistry 212, 1-15.


We investigated variability in the C:234Th ratio of sinking particles and its relationship to changing water column characteristics and plankton ecological dynamics during 29 Lagrangian experiments conducted on six cruises of the California Current Ecosystem Long-Term Ecological Research (CCE-LTER) Program. C:234Th ratios of sinking particles collected by a surface-tethered sediment trap (C:234ThST) varied from 2.3 to 20.5 μmol C dpm−1 over a depth range of 47–150 m. C:2234ThST was significantly greater (by a factor of 1.8) than C:234Th ratios of suspended >51-μm particles collected in the same water parcels with in situ pumps. C:234Th ratios of large (>200-μm) sinking particles also exceeded those of smaller sinking particles. C:2234ThST decreased with depth from the base of the euphotic zone through the upper twilight zone. C:2234ThST was positively correlated with several indices of ecosystem productivity including particulate organic carbon (POC) and chlorophyll (Chl) concentrations, mesozooplankton biomass, and the fraction of Chl >20-μm. Principal component analysis and multiple linear regression suggested that decaying phytoplankton blooms exhibited higher C:2234ThST than actively growing blooms at similar biomass levels. C:2234ThST was positively correlated with indices of the fractional contribution of fecal pellets in sediment traps when the proportion of fecal pellets was low in the traps, likely because of a correlation between mesozooplankton biomass and other indices of ecosystem productivity. However, when fecal pellets were a more important component of sinking material, C:2234ThST decreased with increasing fecal pellet content. C:2234ThST was also positively correlated with the Si:C ratio of sinking particles. Across the dataset (and across depths) a strong correlation was found between C:2234ThST and the ratio of vertically-integrated POC to vertically-integrated total water column 234Th (vC:234Thtot). A mechanistic one-layer, two-box model of thorium sorption and desorption was invoked to explain this correlation. Two empirical models (one using vC:234Thtot; one using depth and vertically-integrated Chl) were developed to predict C:234Th ratios in this coastal upwelling biome. The former regression (log10(C:2234ThST) = 0.43 × log10(vC:234Thtot) + 0.53) was found to also be a reasonable predictor for

C:2234ThST from diverse regions including the Southern Ocean, Sargasso Sea, Subarctic North Pacific, and Eastern Tropical North Pacific.

Sudirjo, E., Buisman, C.J.N., Strik, D.P.B.T.B., 2019. Marine sediment mixed with activated carbon allows electricity production and storage from internal and external energy sources: A new rechargeable bio-battery with bi-directional electron transfer properties. Frontiers in Microbiology 10, 934. doi: 10.3389/fmicb.2019.00934.


Marine sediment has a great potential to generate electricity using a bioelectrochemical system (BES) like the microbial fuel cell (MFC). In this study, we investigated the potential of marine sediment and activated carbon to generate and store electricity. Both internal and external energy supply was validated for storage behavior. Four types of anode electrode compositions were investigated. Two were mixture of different volumes of activated carbon (AC) and mixed with Dutch Eastern Scheldt marine sediment (67% AC, 33% AC) and the others were 100% AC or 100% marine sediment based. Each composition was duplicated. Operating these BES’s under MFC mode with solely marine sediment as the anode electron donor resulted in the creation of a bio-battery system. The recharge time of such bio-battery does depend on the fuel content and its usage. The results showed that marine sediment and activated carbon (AC) were able to generate and store electricity. The 100% AC and the 67% AC mixed with marine sediment electrode were over long term potentiostatic controlled at -100mV vs Ag/AGCl which resulted in a cathodic current and a negative applied voltage. After switching back to MFC operation mode with an external load, the electrode turned into an anode and electricity was generated. This supports our hypothesis that external supply electrical energy was recovered via bi-directional electron transfer. With open cell voltage experiments these AC marine bioanodes showed internal supplied electric charge storage up to 100 mC at short self-charging times (10 and 60 seconds) and up to 2.4 C (3,666 C/m3 anode) when the charging time was increased up to 1 hour. Using a hypothetical cell voltage of 0.2V, this value represents an internal electrical storage density of 0.3 mWh/kg AC marine anode. Furthermore it was remarkable that the BES with 100% marine sediment based electrode also acted like a capacitor similar to the charge storage behaviors of the AC based bioanodes with a maximum volumetric storage of 1,373 C/m3 anode. These insights give opportunities to apply such BES systems as e.g. ex-situ bio-battery to store and use electricity for off-grid purpose in remote areas.

Suh, Y.J., Diefendorf, A.F., Bowen, G.J., Cotton, J.M., Ju, S.-J., 2019. Plant wax integration and transport from the Mississippi River Basin to the Gulf of Mexico inferred from GIS-enabled isoscapes and mixing models. Geochimica et Cosmochimica Acta 257, 131-149.


Understanding the fate of terrestrial plant waxes from source to sink is critical for improving paleoclimate interpretations from sedimentary plant waxes. However, there is limited knowledge about the controls on plant wax integration and transport in large catchments with multiple biomes and climates. To address this lack of understanding, we investigated the vegetation and climatic controls on plant wax integration and transport from the Mississippi River Basin (MRB), the largest river in the U.S., to the Gulf of Mexico (GOM). We first estimated the geographic distribution of n-alkane carbon (δ13Calk) and hydrogen (δ2Halk) isotopic compositions (i.e. isoscapes) in the MRB using plant isotope fractionation calibrations from North America and similar climate regions for the pre-industrial. We utilized two different vegetation maps (i.e. biome map and %C4 map) and two plant isotope fractionation estimation approaches, and discussed advantages and disadvantages of each

method. Then, we developed mixing models weighting the isotope values by biological and climatic parameters (i.e. vegetation area, n-alkane concentration by chain lengths, net primary productivity (NPP), and runoff) and their combinations to test the sensitivity of basin-integrated plant wax isotopic compositions to these variables. Our approach does not factor in soil stocks of plant wax nor degradation in transit, as future work will need to constrain these factors for the MRB for the period of interest. Vegetation area weighting alone predicted relatively high C4 plant contributions to the pool of waxes exported from the basin. When n-alkane concentration in leaves, NPP, or runoff was considered, the contribution of forest-derived plant waxes increased. Sensitivity of plant wax isotopic compositions to productivity and transport efficiency varied among models and chain lengths. For example, n-C29 alkanes were sensitive to plant wax contribution increases from forests whereas n-C33 alkanes were more sensitive to increases in C4 grassland productivity. The plant wax concentration and NPP were combined as an estimate for total wax productivity, and a combination of this total wax productivity and runoff were used to simulate both production and transport. These multi-parameter models estimated the highest plant wax contribution from C3 forests because these areas were calculated to have the highest productivity and greatest runoff. Despite large differences in δ13Calk and δ2Halk values across the MRB, variation in the predicted δ13C and δ2H of exported n-alkanes is small across all models. This small range is consistent with a calculated predominance of plant wax export from wet and tree-dominated biomes and suggests that drier and C4 grass-dominated biomes may be under-represented in the sedimentary plant wax record.

Sun, L., Tuo, J., Zhang, M., Wu, C., Chai, S., 2019. Pore structures and fractal characteristics of nano-pores in shale of Lucaogou Formation from Junggar Basin during water pressure-controlled artificial pyrolysis. Journal of Analytical and Applied Pyrolysis 140, 404-412.


To analyse the pore structures and fractal characteristics of nano-pores during OM evolution, a series artificial hydrous pyrolysis experiments were conducted on shale samples at 250℃∼500 under 50 ℃MPa water pressure. Low-pressure N2 adsorption was performed to investigate the pore structure and fractal dimension of pores on pyrolysis residues. Based on the model by Frenkel-Halsey-Hill, the fractal dimensions of D (relative pressure P/Po from 0 to 1), D1 (before P/Po = 0.5) and D2 (after P/Po = 0.5) were calculated. With the simulation temperature increasing, the pyrolysis products presented three stages that corresponded with the lower maturity (< 350 ), maturity (350℃ ℃∼400 ) and ℃higher maturity (400℃∼500 ) stages. For pore structures, Type IV isotherms and Type H3 ℃hysteresis loops occurred in the shale samples, and the adsorbed nitrogen quantity presented an increasing tendency. By analysing the relationship between the pore volume, surface area, and average diameter with OM evolution, pores also occurred during a stage of no change and increased and increased sharply, all of which corresponded to the thermal evolution stages. In the fractal dimension, the relationships between D, D1, D2 and the simulation temperature showed that shale heterogeneity was associated with the OM evolution stage. The rand-size relatio hip between D1 and D2 at different thermocatalytic stages suggested that the main influencing factors on the adsorption of shale gas were the micro-, meso-pores and the quantities of micropores. Therefore, through the research on pore structure and the fractal dimension of pyrolysis residues, we could determine the developmental characteristics of pores and the changing situation of shale heterogeneity based on the migration, preservation, and accumulation of generated hydrocarbons during OM evolution. This research provides a theoretical foundation for the exploration and exploitation of shale gas.



Surfactant enhanced oil recovery is promising in tight formations by altering the wettability, reducing the interfacial tension, and promoting the counter-current imbibition process. In this paper, surfactant Huff-n-Puff in Bakken tight reservoir was studied based on modelling and simulation of a Middle Bakken well using actual field data. The effects of wettability alteration and interfacial reduction by surfactant solution were modeled based on laboratory data. The Embedded Discrete Fracture Model (EDFM) method was used to efficiently handle hydraulic fractures in the model in a fast way using non-neighboring connections as a new technique in this simulation study. We used a sector model with the EDFM method to conduct the surfactant Huff-n-Puff sensitivity simulation after the grid size optimization. We considered six sensitivity factors and each simulation case was conducted after history matching. Based on the simulation results, we found that the number of Huff-n-Puff cycles and the surfactant concentration are the most important factors, followed by surfactant adsorption, soaking time, injection time and injection rate. The percentage of oil recovery increase over the primary oil recovery ranges from 1.1% to 25.2%. This study can provide critical insights of key parameters affecting the surfactant flooding efficiency in Middle Bakken tight oil reservoir.

Sun, T., Bake, K.D., Craddock, P.R., Gunawan, B., Darnell, L.M., Bissada, K.K., Pomerantz, A.E., 2019. Acid demineralization with pyrite removal and critical point drying for kerogen microstructural analysis. Fuel 253, 266-272.


Hydrocarbon storage and transport in unconventional shale resources occurs predominantly within pores hosted by kerogen (solid and insoluble organic matter in sedimentary rocks). Kerogen-hosted pores are small, so physiochemical interactions between pore fluids and pore surfaces (e.g., adsorption) are particularly important in shale. The understanding and prediction of hydrocarbon storage and transport in shale is dependent, therefore, upon the correct understanding of both chemical composition and pore geometry of kerogen. Several recent studies have attempted to construct molecular models of kerogen physical and/or chemical structure. Developing these models is challenging, in part because of the lack of laboratory samples of kerogen for experimental characterization that preserve both its chemical and microstructural properties representative of those in the subsurface.

This study presents an integrated kerogen-isolation procedure that combines closed-system chemical demineralization with pyrite removal and critical point drying. The method produces a kerogen that is not only high in chemical purity but more representative of kerogen microstructure that occurs in the subsurface. Characterization of kerogen microstructure, which can be performed by direct measurement of the isolate obtained by this procedure, is essential to better understand and predict the storage, transport, and production hydrocarbons from unconventional resources.

Sun, Y., Liu, Z., Li, Q., Deng, S., Guo, W., 2019. Controlling groundwater infiltration by gas flooding for oil shale in situ pyrolysis exploitation. Journal of Petroleum Science and Engineering 179, 444-454.


An inrush of groundwater will absorb the heat injected in oil shale in situ pyrolysis exploitation, which will reduce the pyrolysis efficiency and generate a large amount of oil-containing water. This paper proposed a novel method of water-stopping by gas flooding to solve the problem of groundwater infiltration into the in situ pyrolysis zone of oil shale. In this paper, numerical simulation by TOUGH2/EOS3 and field experiment studies were conducted, with the general aim of this study focused on the establishment of the inflatable area and the long-term water-stopping mechanism. The simulation results showed that the resistance of gas to groundwater flow and the pressure balance of the gas-water interface at the inflatable area front were the main mechanisms of water-stopping. The water yield in the pyrolysis zone decreased significantly from 6 m3/h to nearly 0 m3/h after the inflatable area was established, and the effective water-stopping radius exceeded 50 m around a single well. Furthermore, a field-scale water-stopping by gas flooding experiment was carried out in the National Pilot Project for Oil Shale in situ Exploitation of China (NPOSE), with the results demonstrating that the water yield could be reduced from 6 m3/h to 0.5 m3/h after gas injection, which was basically consistent with the numerical simulation results. Cracked oil (2.85 tons) was successfully obtained at high energy efficiency of approximately 6.1. Consequently, it is verified that the method proposed in this paper has the desired effect of water-stopping and practical application value, which provides technical support for large-scale oil shale in situ pyrolysis exploitation around the world.

Sun, Y.D., Zulla, M.J., Joachimski, M.M., Bond, D.P.G., Wignall, P.B., Zhang, Z.T., Zhang, M.H., 2019. Ammonium ocean following the end-Permian mass extinction. Earth and Planetary Science Letters 518, 211-222.


The aftermath of end-Permian mass extinction was marked by a ∼5 million year interval of poorly-understood, extreme environments that likely hindered biotic recovery. Contemporary nitrogen isotope variations are considered, using a new conceptual model, to support a scenario that shows intensive nitrate-removal processes gradually depleted the global oceanic nitrate inventory during long-lasting oceanic anoxia. Enhanced nitrogen fixation shifted the oceanic nitrogenous nutrient (nutrient-N) inventory to an ammonium-dominated state. Ammonium is toxic to animals and higher plants but fertilizes algae and bacteria. This change in ocean chemistry could account for the intense and unexplained losses of nektonic taxa and the proliferation of microbial blooms in the Early Triassic. The transition from a nitrate ocean to an ammonium ocean was accompanied by a decrease in respiration efficiency of organisms and a shrinking oceanic nutrient-N inventory, ultimately leading to generally low productivity in the Early Triassic oceans. These unappreciated nutrient changes during episodes of prolonged ocean anoxia may be the key life-limiting factor at such times.

Suneel, V., Saha, M., Rathore, C., Sequeira, J., Mohan, P.M.N., Ray, D., Veerasingam, S., Rao, V.T., Vethamony, P., 2019. Assessing the source of oil deposited in the surface sediment of Mormugao Port, Goa - A case study of MV Qing incident. Marine Pollution Bulletin 145, 88-95.


In June 2016, a cruise vessel was grounded in the Mormugao Port, resulting in unnoticed oil spill. The surface water and sediment samples were collected from the vicinity of the ship, and also an oil sample from the ship (OIL). These samples were subject to petroleum biomarker such as pentacyclic triterpenes (hopanes) and compound specific carbon isotopic (δ13C) analyses to assess the source of hydrocarbon pollution in the Mormugao Port. While no clear trend was observed in water samples, the bottom surface sediments did show an identical pattern of hopanes with the oil. The chemometric

analyses of hopane Diagnostic Ratios (DRs) and δ13C ratios confirmed the ship oil as the source of oil pollution in sediments. Whereas the water is comparatively more dynamic than the sediment, the physical processes arising out of winds, waves, tides and currents might have dispersed the oil away from the grounded ship.

Takeya, M., Shimokawara, M., Elakneswaran, Y., Okano, H., Nawa, T., 2019. Effect of acid number on the electrokinetic properties of crude oil during low-salinity waterflooding. Energy & Fuels 33, 4211-4218.


Understanding crude oil/brine interface chemistry is essential to elucidating the effect of low-salinity waterflooding (LSWF) on enhanced oil recovery (EOR). The acid and base functional groups in crude oil result in an electrostatic interaction with the rock’s surface, thereby affecting wettability conditions. Moreover, the content of carboxyl acid components is a key factor influencing electrostatic interaction during LSWF. In this study, the number of carboxyl groups in four different crude oils with varying acid number (AN) was estimated using a combination of zeta potential experiments and a triple-layer surface complexation model. In addition, the surface complexation modeling parameters for the dissociation of carboxyl groups and the adsorption of calcium and magnesium ions were also determined. The experimentally determined parameters and carboxyl groups sufficiently predicted the crude oil/brine interface at high and low salinities of seawater and formation water. The density of carboxyl groups (expressed in sites/nm2) is logarithmically related to the AN of crude oil, and it is revealed that the effect of AN on the density is lower for high-AN crude oil. Further, for crude oils with high AN, divalent cations exhibit higher adsorption ability than those with low-AN crude oil. The percentage of resin components in crude oil has a linear relationship with the number of carboxyl sites, thus indicating the importance of resin components in crude oil/brine interface chemistry. The study discusses the influence of AN on potential distribution and possible wettability alteration by LSWF in sandstone and carbonate reservoirs.

Tamara, S., Hoek, M., Scheltema, R.A., Leney, A.C., Heck, A.J.R., 2019. A colorful pallet of B-phycoerythrin proteoforms exposed by a multimodal mass spectrometry approach. Chem 5, 1302-1317.

https://doi.org/10.1016/j.chempr.2019.03.006

Cyanobacteria and red algae represent some of the oldest lifeforms on the planet. During billions of years of evolution, they have fine-tuned the structural details of their light-harvesting antenna, called phycobilisomes, which represents one of the most efficient systems for light harvesting and energy transfer. Yet, the exact details of phycobilisome assembly and energy transfer are still under investigation. Here, we employed a multi-modal mass spectrometric approach to unravel the molecular heterogeneity within B-phycoerythrin, the major phycobiliprotein in the red algae P. cruentum. B-phycoerythrin consists of 12 subunits (αβ) 12 arranged in a ring with the central cavity housing a linker (γ) subunit, which is crucial for stabilizing B-phycoerythrin within the phycobilisome. Using top-down MS, we unravel the heterogeneity in the γ proteoforms, characterizing the distinct γ chains and multiple isobaric chromophores they harbor. Our data highlight the key role γ plays in phycobilisome organization that enables optimal light transmission.

Tamayo-Figueroa, D.P., Castillo, E., Brandão, P.F.B., 2019. Metal and metalloid immobilization by microbiologically induced carbonates precipitation. World Journal of Microbiology and Biotechnology 35, Article 58.

https://doi.org/10.1007/s11274-019-2626-9

The industrialization and growth of human population has increased the release and accumulation of metals and metalloids in the environment. Bioaccumulation and exposure to these elements have been associated with different types of diseases and cancer, thus looking for alternatives that decrease their bioavailability in the environment is crucial. Microbiologically induced carbonates precipitation (MICP) has been proposed as a potential bioremediation method to immobilize contaminating metals and metalloids. Studies published to date have mainly used ureolytic bacteria, reporting metal(loid)s removal percentages up to 100% for some toxic elements, thus demonstrating the effectiveness of this treatment. Various genera of bacteria, particularly Gram-positive, have been reported with MICP abilities. More recently, fungi have also been proposed as a viable alternative for the removal of these toxic elements by carbonate precipitation. This mini-review presents updated information about the main studies carried out to date using different types of microorganisms that perform MICP to decrease the environmental bioavailability of toxic metals and metalloids through the formation of metallic carbonates.

Tamborrino, L., Himmler, T., Elvert, M., Conti, S., Gualtieri, A.F., Fontana, D., Bohrmann, G., 2019. Formation of tubular carbonate conduits at Athina mud volcano, eastern Mediterranean Sea. Marine and Petroleum Geology 107, 20-31.


Tubular carbonate conduits (TCC) represent the termination of fluid plumbing systems in environments of hydrocarbon seepage and play a relevant role in the discharge of methane from sub-seafloor sediments to the water column. However, the biogeochemical reactions and biological activities involved in their formation are not fully understood. To address this, TCC samples were collected with a remotely operated vehicle from the seabed on the SW flank of the Athina mud volcano in the eastern Mediterranean Sea. Petrographic, mineralogical, stable carbon and oxygen isotope and lipid biomarker analyses were performed to elucidate the formation processes of the tubular carbonates. Clotted and fibrous aragonite form the internal lining of the cavities, while the outer portion of the tubes is formed by micritic Mg-calcite cementing hemipelagic sediment. 13C-depleted Mg-calcite and aragonite (as low as −14.4‰ V-PDB) and lipid biomarkers (archaeol, −89.8‰ V-PDB) indicate that carbonate precipitation was influenced by sulfate-dependent anaerobic oxidation of methane (AOM). AOM locally enhances aragonite precipitation, thereby facilitating early lithification of the conduits within the mud volcano sediments. The size and morphology of the TCC comparable with the buried portion of tubeworm colonies found in the proximity of the sampling site. However, our results suggest that TCC likely formed by the action of burrowing organism rather than being mineralizations of the tubeworm colonies. This study provides new insights into the interpretation and understanding of TCC, highlighting the role of macrofaunal activity in the formation of migration pathways for hydrocarbon-rich fluids on the flank of a mud volcano.

Tang, X., Zhou, X., Peng, Y., 2019. Molecular simulation of methane adsorption within illite minerals in the Longmaxi Formation shale based on a grand canonical Monte Carlo method and the pore size distribution in southeastern Chongqing, China. Journal of Natural Gas Geoscience 4, 111-119.


In order to investigate the pore structure and the adsorption capacity of illite with respect to the methane in the Longmaxi Formation, isothermal adsorption experiments utilizing mercury intrusion, liquid nitrogen, and low-temperature carbon dioxide techniques were applied to the shale samples from southeastern Chongqing. The adsorption characteristics of illite slit pores varying in diameters were simulated using a Monte Carlo method. The results reveal that the pore volume and the specific surface area of the shale are primarily supplied by pore diameters measuring less than 2 nm. Illite is one of the primary components of the clay mineralogy within the shale that forms parallel or nearly-parallel plate pores. For pore sizes ranging from 0.5 nm to 0.9 nm (at conditions of 303.15 K and 8 MPa), the methane molecules are affected by van der Waals and electrostatic forces that leads to a large excess in the adsorption capacity of methane. Once the pore size becomes less than 0.9 nm, the methane adsorption becomes primarily affected by van der Waals forces. At the said size, the excess adsorption capacity of methane initially decreases, after which it remains constant with an increase in the pore size. The free gas content surges with the growing pore diameters. The average equivalent adsorption heat reflects that the adsorption of methane onto illite is characterized by physical adsorption. During the adsorption process, when the pore size is between 0.5 nm and 1.2 nm, the average equivalent adsorption heat decreases rapidly with an increase in the pore diameter. In pore size that exceeds 1.2 nm, the adsorption intensity between the methane molecules and the illite slit becomes stable. In this case, the average adsorption heat is measured to be 6.72 kJ/mol. Meanwhile, the monolayer of methane is adsorbed onto the pore wall and the local density of methane exhibits the characteristics evident of that of a single peak when the pore size is between 0.5 nm and 0.8 nm. The adsorption mode changes from single-layer adsorption to double-layer adsorption when the pore size is between 0.8 nm and 1.2 nm. In addition, the local density curve changes from unimodal to bimodal. In pores sized larger than 1.2 nm, the free volume of methane adsorption can be larger, wherein the local density curve is bimodal.



Anaerobic ammonium-oxidizing (anammox) bacteria convert ammonium and nitrite into N2 in a chemolithoautotrophic way, meaning that they utilize CO2/HCO3 solely as their carbon sources. Such autotrophic behavior limits their competitiveness with heterotrophic microorganisms in both natural environments and engineered systems. Recently, environmental metagenomic results have indicated the capability of anammox bacteria to metabolize short-chain fatty acids, further confirmed by limited experimental evidence based on highly enriched cultures. However, clear evidence is difficult to get because of the limits of traditional methodologies which rely on the availability of a pure anammox culture. In this study, we identified and quantified the uptake of acetate and propionate, on a single-cell level, by an anammox consortium that was dominated by Candidatus Jettenia asiatica (relative abundance of 96%). The consortium, growing in granular form with an average relative abundance of anammox bacteria of 96.0%, was firstly incubated in a13C-labelled acetate or propionate medium; then microtome sections were scanned by a nanometer-scale secondary ion mass spectrometer (NanoSIMS). The NanoSIMS scannings revealed that the consortium enriched acetate and propionate at a >10 times higher efficiency than bicarbonate incorporation. Our results also suggest that acetate or propionate was likely not assimilated by J. asiatica directly, but firstly oxidized to CO2, which then served as carbon sources for the follow-up autotrophy in J. asiatica cells. Furthermore, more [15N]ammonium was enriched by the propionate-fed consortium than the acetate-fed consortium despite that exactly the same amount of 13C atoms were supplied. Our study strongly indicates an

alternative lifestyle, namely organotrophy, in addition to chemolithoautotrophy of anammox bacteria, making it more versatile than often expected. It suggests that the niche of anammox bacteria in both natural and engineered ecosystems can be much broader than usual assumed. Recognising this is important for their role in wastewater treatment and the global nitrogen turn-over rates.

Tavakkoli, M., Sung, C.-A., Kuang, J., Chen, A., Hu, J., Vargas, F.M., 2019. Effect of carbon steel corrosion on asphaltene deposition. Energy & Fuels 33, 3808-3815.


In this work, the effect of carbon steel corrosion on asphaltene deposition tendency was investigated. A new experimental setup, consisting of a multi-section column made of polytetrafluoroethylene (PTFE), was built and packed with carbon steel spheres, which was then used to quantify the deposition of asphaltenes under different conditions. It was found that, in the presence of iron ions in a brine-in-oil emulsion, the amount of deposited material upon the addition of an asphaltene precipitant, such as n-heptane, was significantly higher than in the case of iron-free brine. In addition, it was observed that asphaltenes have a higher tendency to deposit on the rust-covered metallic surfaces compared to the clean and smooth carbon steel spheres. Also, increasing the surface roughness can lead to a higher asphaltene deposition rate. To reduce the extent of asphaltene deposition induced by the tube corrosion, a chelating agent, ethylenediaminetetraacetic acid (EDTA), was added to sequestrate the iron ions. The results obtained showed that EDTA is able to mitigate the extent of corrosion-induced asphaltene deposition on metallic surfaces. Consequently, when the corrosion problem is addressed, asphaltene deposition may actually subside. The deposition tests also revealed a surprising result: even though EDTA reduced the amount of asphaltene deposition on carbon steel spheres, it significantly increased the amount of deposit collected on the PTFE surface. With these results, we conclude that corrosion and asphaltene deposition are two problems that must be concurrently investigated and that strategies for their mitigation should account for the interactions between chemicals in the bulk phase and also with the exposed surfaces.

Theiling, B.P., Coleman, M., 2019. The relationship of diagenesis with a complex microbial ecosystem in the phosphatic interval of the Miocene Monterey Formation: evidence from stable isotopes and mineralogy. Marine Geology 413, 112-128.


A combination of evidence from mineralogy, sulfur and oxygen stable isotope ratios from early diagenetic carbonate associated sulfate (CAS) and structurally substituted sulfate in phosphate (both termed CAS here), and carbon and oxygen stable isotope ratios from carbonate, describe a complex redox system and complex microbial ecosystem within the phosphate-rich interval of the Monterey Formation. δ34S and δ18O of CAS are lower than Miocene seawater sulfate, as reconstructed from marine evaporite and barite minerals. Combined with mineralogical speciation modeling and mineralogical observations, isotopically low CAS isotope values suggest mixing from three isotopically characterized sulfate pools: two isotopically higher sulfate pools, one with the composition of Miocene seawater sulfate and a second isotopically evolved porewater modified by sulfate reducing microbes (SRM), and a third isotopically lower porewater sulfate pool resulting from the oxidation of H2S (produced by SRM) by sulfide oxidizing bacteria (SOB). High carbonate δ13C and diagenetic dolomite validates prior claims of methanogenesis. Differences in mineralogy are consistent with differences in isotope ratios (e.g. higher δ13C in dolomites), suggesting products from a vertical distribution of oxic to anoxic redox environments and associated ecosystems are preserved. These mineralogical and isotopic fluctuations repeat in various facies changes, suggesting that redox

environments fluctuated over time. This interpretation is supported by prior sedimentologic analysis which interpreted that deposition of the phosphatic interval of the Monterey Formation was influenced by gravity-deposition processes promoted by tectonic activity. Gravity-deposition would serve to transport more oxygenated waters to the deep-water depositional environment and support microbially-mediated sulfide oxidation at depth, whereby H2S generated by SRM in the absence of sufficient iron could diffuse upward to a more oxygenated zone. Near the suboxic-oxic boundary, H2S oxidation would decrease porewater pH slightly and inhibit the preservation of carbonate minerals and promote precipitation of phosphate. Increasing depth in sediments generates successively more reducing conditions, promoting sulfate reduction, which may have been coupled with the anaerobic oxidation of methane and carbonate mineral precipitation. The most reducing conditions would support methanogenesis and dolomite production after consumption of the majority of sulfate.

Thibault, A., Derenne, S., Parlanti, E., Anquetil, C., Sourzac, M., Budzinski, H., Fuster, L., Laverman, A., Roose-Amsaleg, C., Viollier, E., Huguet, A., 2019. Dynamics of organic matter in the Seine Estuary (France): Bulk and structural approaches. Marine Chemistry 212, 108-119.


Estuaries are important ecosystems from environmental and economical point of views and are the place of numerous transformations of organic matter (OM) during the transfer from land to the ocean. The dynamics of OM in estuarine systems is complex and was only rarely investigated at the structural or molecular level, even though OM transformation in the estuarine aquatic and sediment compartments involves processes taking place at this level. The aim of this study was to constrain the sources and fate of the OM in the Seine Estuary, one of the largest estuaries in France. The spatiotemporal dynamics of the OM along the estuary was investigated by comparing the bulk (elemental and isotopic composition) and structural (solid state 13C nuclear magnetic resonance) features of the different pools of OM – dissolved OM (DOM), particulate OM (POM) and sediment OM collected during five sampling campaigns. Reverse osmosis coupled with electrodialysis (RO/ED) was used to concentrate and isolate DOM, yielding an average organic carbon recovery of 59% (± 15%). RO/ED had a limited effect on DOM properties, DOM showing >75% of similarity with initial estuarine samples based on 3D fluorescence measurements. Bulk and structural analyses of DOM, POM and sedimentary OM showed that OM is mainly of aquatic origin in the Seine Estuary, regardless the OM pool. Nevertheless, significant differences in chemical composition between the three OM pools were observed: higher C/N ratios, carbohydrate, lipid and protein content as well as lower char and lignin contents in DOM than in the other two compartments. Spatial variations of OM properties, for POM and to a lesser extent DOM, were observed along the Seine Estuary based on δ13C and Δ14C analyses and 13C NMR-derived protein and lipid contents, showing the transition from a riverine to a marine-dominated system. In the mixing zone of the estuary, the Δ14C composition of the sediment OM was related to the tidal strength, with strong tides leading to the resuspension of recent sediment OM and weak tides allowing the deposition of recent aquatic OM. Altogether, the combination of bulk and structural techniques showed that the Seine Estuary OM quality is mainly related to the compartment (DOM/POM/sediment) and to a lesser extent to the sampling zone (upstream/maximum turbidity zone/downstream). The approach proposed for the characterization of the Seine Estuary OM could be applied to other estuaries, allowing a better understanding of the complex OM dynamics in such ecosystems.

Thoby, M., Konhauser, K.O., Fralick, P.W., Altermann, W., Visscher, P.T., Lalonde, S.V., 2019. Global importance of oxic molybdenum sinks prior to 2.6 Ga revealed by the Mo isotope composition of Precambrian carbonates. Geology 47, 559-562.

https://doi.org/10.1130/G45706.1

Sedimentary molybdenum (Mo) isotope compositions are a promising paleoredox indicator because the Mo isotope composition of seawater reflects the balance between anoxic and oxic sinks. Most available data are from shales; however, the Mo isotope composition of carbonates also reflects the composition of ancient seawater. Here, we provide an expanded data set of carbonate Mo isotope compositions, including the first data for carbonates older than 2.64 Ga, which we evaluate against a compilation of published data for carbonates, shales, and iron formations spanning geological time. Archean carbonate samples reveal maximum δ98Mo values that are generally above 1‰. These heavy values indicate that Mn(IV)-oxide or Fe(III)-oxide sinks were sufficiently important to influence the Mo isotope composition of seawater as far back as 2.93 Ga. Comparison of Mo isotope and rare earth element data, as well as residence time considerations, indicates that this metal-oxide influence was likely global. Available Mo isotope data for shales over the same time period generally show crustal values, which we attribute to negligible authigenic enrichment of Mo from seawater due to low ambient concentrations and a paucity of euxinic conditions. Our work demonstrates that the carbonate record provides important new insights into marine paleoredox conditions, especially when shale records are absent or unsuitable, and reinforces the emerging paradigm that oxic Mo sinks were important in the marine realm prior to 2.7 Ga.

Tian, T., Zhou, S., Fu, D., Yang, F., Li, J., 2019. Calculation of the original abundance of organic matter at high-over maturity: A case study of the Lower Cambrian Niutitang shale in the Micangshan-Hannan Uplift, SW China. Journal of Petroleum Science and Engineering 179, 645-654.


The evaluation of shale source rocks is one of the most basic and important processes during shale gas exploration to estimate the hydrocarbon genetic potential, especially for shale source rocks at high-over maturity. This study focuses on the geochemistry of Niutitang shale at high-over maturity to identify the practicability of organic matter abundance calculation. Ninety-eight Niutitang shale samples from outcrops in the Micangshan-Hannan Uplift were selected and tested. The geochemical characteristics of the Niutitang shale source rocks including the total organic carbon (TOC), pyrolysis data, thermal maturity, kerogen types and clay mineral composition, were investigated using tests of C/N elemental analysis, Rock-Eval, bitumen reflectance (Rb), organic carbon isotope (δ13Corg) and X-ray diffraction (XRD). Then, the formulas for calculating the coefficient of original TOC (Kc) and original genetic potential S1+S2 (Ks) were deduced using the pyrolysis data and the results before and after calculation were analyzed. The result of the present work imply that it is necessary and reasonable to calculate the original abundance of organic matter in marine shale source rocks at high-over maturity and that a TOC of at least 1.0% may be appropriate to predict favorable zones of marine shale at high-over maturity in China.

Toggweiler, J.R., Druffel, E.R.M., Key, R.M., Galbraith, E.D., 2019. Upwelling in the ocean basins north of the ACC: 1. On the upwelling exposed by the surface distribution of Δ14C. Journal of Geophysical Research: Oceans 124, 2591-2608.

https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/2018JC014794

Abstract: The upwelling associated with the ocean's overturning circulation is hard to observe directly. Here, a large data set of surface Δ14C measurements is compiled in order to show where deep water is brought back up to the surface in the ocean basins north of the Antarctic Circumpolar Current (ACC). Maps constructed from the data set show that low-Δ14C deep water from the ACC is drawn

up to the surface in or near the upwelling zones off Northwest Africa and Namibia in the Atlantic, off Costa Rica and Peru in the Pacific, and in the northern Arabian Sea in the Indian Ocean. Deep water also seems to be reaching the surface in the subarctic Pacific gyre near the Kamchatka Peninsula. The low-Δ14C water drawn up to the surface in the upwelling zones is also shown to spread across the ocean basins. It is easily seen, for example, in the western Atlantic off Florida and in the western Pacific off New Guinea and Palau. The spreading allows one to estimate the volumes of upwelling, which, it turns out, are similar to the volumes of large-scale upwelling derived from inverse box models. This means that very large volumes of cool subsurface water are reaching the surface in and near the upwelling zones—much larger volumes than would be expected from the local winds.

Plain Language Summary: The deep layers of the ocean are filled with cold dense water that sinks from the surface near Antarctica and in the northern North Atlantic. This process is understood reasonably well. The countervailing process—the way that the dense water is brought back up to the surface—is not as well understood. Oceanographers now agree that the ocean's deep water is drawn back up to the surface (“upwelled”) mainly around Antarctica as part of the wind‐driven overturning in the Antarctic Circumpolar Current (ACC). But cool water is also known to reach the surface in upwelling zones around the ocean's margins. Here we map the upwelling north of the ACC with the radioactive isotope carbon‐14 and show that the deep water upwelled to the surface around Antarctica seems to be drawn up to the surface a second time in the upwelling zones. The water drawn up to the surface in the upwelling zones then flows back to the North Atlantic and sinks again to complete the cycle.



Dolomite rarely occurs in modern marine environments, while it is ubiquitous in the geological record. This apparent contradiction made the formation mechanism of dolomite a long-standing problem haunting sedimentologists. However, dolomite is a constituent of many modern seep carbonates, providing an opportunity to investigate the conditions favoring dolomite formation at low temperatures in the shallow subseafloor. This study reports the petrology, mineralogy, carbon and oxygen stable isotopic compositions, as well as sulfur isotopic compositions of both carbonate-associated sulfate (CAS) and chromium reducible sulfur (CRS) of a set of dolomite-bearing carbonates from two seep sites (GC140 and GB382) on the northern slope of the Gulf of Mexico. The δ13C values of carbonates vary from −50.0‰ to 3.2‰ (V-PDB), confirming that carbonate minerals mostly resulted from methane oxidation. The corresponding δ18O values range from 2.6‰ to 5.9‰ (V-PDB), reflecting formation close to equilibrium with seawater composition. All carbonate samples with dolomite show similar petrologies and lack skeletal remains of seep-dwelling metazoans. The homogenous texture of microcrystalline dolomite agrees with its formation in the shallow subseafloor. Dolomite-bearing samples reveal δ18OCAS/δ34SCAS slopes of 0.425 and 0.435 for the two study sites, respectively. Such high slopes are significantly different from the smaller slopes of seep carbonates consisting of calcite from Gulf of Mexico seeps, suggesting low overall sulfate reduction rates during dolomite formation. This explanation is also supported by relatively high δ34SCRS values ranging from −29.4‰ to 19.0‰ (V-CDT) and the positive correlation of these values with dolomite contents. Interestingly, an approximately stoichiometric dolomite sample yielded the most positive δ34SCRS value, indicating a formation environment typified by low replenishment of seawater sulfate at a supposedly relatively deep sulfate methane transition zone (SMTZ). Overall, these results confirm that dolomite formation is facilitated where the SMTZ is situated at relatively great depth,

where sulfate reduction rates are slowed down due to the buildup of high contents of dissolved sulfide and low seawater sulfate replenishment.

Trimpin, S., Inutan, E.D., Karki, S., Elia, E.A., Zhang, W.-J., Weidner, S.M., Marshall, D.D., Hoang, K., Lee, C., Davis, E.T.J., Smith, V., Meher, A.K., Cornejo, M.A., Auner, G.W., McEwen, C.N., 2019. Fundamental studies of new ionization technologies and insights from IMS-MS. Journal of The American Society for Mass Spectrometry 30, 1133-1147.

https://doi.org/10.1007/s13361-019-02194-7

Exceptional ion mobility spectrometry mass spectrometry (IMS-MS) developments by von Helden, Jarrold, and Clemmer provided technology that gives a view of chemical/biological compositions previously not achievable. The ionization method of choice used with IMS-MS has been electrospray ionization (ESI). In this special issue contribution, we focus on fundamentals of heretofore unprecedented means for transferring volatile and nonvolatile compounds into gas-phase ions singly and multiply charged. These newer ionization processes frequently lead to different selectivity relative to ESI and, together with IMS-MS, may provide a more comprehensive view of chemical compositions directly from their original environment such as surfaces, e.g., tissue. Similarities of results using solvent- and matrix-assisted ionization are highlighted, as are differences between ESI and the inlet ionization methods, especially with mixtures such as bacterial extracts. Selectivity using different matrices is discussed, as are results which add to our fundamental knowledge of inlet ionization as well as pose additional avenues for inquiry. IMS-MS provides an opportunity for comparison studies relative to ESI and will prove valuable using the new ionization technologies for direct analyses. Our hypothesis is that some ESI-IMS-MS applications will be replaced by the new ionization processes and by understanding mechanistic aspects to aid enhanced source and method developments this will be hastened.

Tserolas, P., Maravelis, A.G., Tsochandaris, N., Pasadakis, N., Zelilidis, A., 2019. Organic geochemistry of the Upper Miocene-Lower Pliocene sedimentary rocks in the Hellenic Fold and Thrust Belt, NW Corfu island, Ionian sea, NW Greece. Marine and Petroleum Geology 106, 17-29.


The northwestern margin of the Hellenic Fold and Thrust Belt situated along the southern edge of the Dinarides – Albanides - Hellenides continental convergent zone, has been studied in terms of its hydrocarbon generating potential. More than a hundred (100) samples of the Upper Miocene-Lower Pliocene sedimentary rocks from several sites in Corfu Island were analyzed using Rock-Eval VI pyrolysis, while a selected representative group was further analyzed using bitumen extraction, open column chromatography and gas chromatography-mass spectrometry. Results of this investigation revealed units with sufficient organic material of good enough quality and quantity to be considered as potential source rocks. A general Type III kerogen was identified, indicating terrestrial origin of the organic matter. Tmax and Production Index values further indicate that the most promising parts of the sediments are immature with respect to oil generation and have not experienced high temperature during burial. n-alkanes distribution for selected samples of the Northern Miocene to Pliocene mudstones present dominance of the long-chain components. Immaturity of the organic matter is also evident by the low Pr/Ph and 20S/(20S + 20R) steranes ratios.

Tuerena, R.E., Ganeshram, R.S., Humphreys, M.P., Browning, T.J., Bouman, H., Piotrowski, A.P., 2019. Isotopic fractionation of carbon during uptake by phytoplankton across the South Atlantic subtropical convergence. Biogeosciences Discussions 2019, 1-29.


The stable isotopic composition of particulate organic carbon (δ13CPOC) in the surface waters of the global ocean can vary with the aqueous CO2 concentration ([CO2(aq)]) and affects the trophic transfer of carbon isotopes in the marine food web. Other factors such as cell size, growth rate and carbon concentrating mechanisms decouple this observed correlation. Here, the variability in δ13CPOC is investigated in surface waters across the south subtropical convergence (SSTC) in the Atlantic Ocean, to determine carbon isotope fractionation (εp) by phytoplankton and the contrasting mechanisms of carbon uptake in the subantarctic and subtropical water masses. Our results indicate that cell size is the primary determinant of δ13CPOC across the Atlantic SSTC in summer. Combining cell size estimates with CO2 concentrations, we can accurately estimate εp within the varying surface water masses in this region. We further utilize these results to investigate future changes in εp with increased anthropogenic carbon availability. Our results suggest that smaller cells, which are prevalent in the subtropical ocean, will respond less to increased [CO2(aq)] than the larger cells found south of the SSTC and in the wider Southern Ocean. In the subantarctic water masses, isotopic fractionation during carbon uptake will likely increase, both with increasing CO2 availability to the cell, but also if increased stratification leads to decreases in average community cell size. Coupled with decreasing δ13C of [CO2(aq)] due to anthropogenic CO2 emissions, this change in isotopic fractionation and lowering of δ13CPOC may propagate through the marine food web, with implications for the use of δ13CPOC as a tracer of dietary sources in the marine environment.

Turetsky, M.R., Abbott, B.W., Jones, M.C., Anthony, K.W., Olefeldt, D., Schuur, E.A.G., Koven, C., McGuire, A.D., Grosse, G., Kuhry, P., Hugelius, G., Lawrence, D.M., Gibson, C., Sannel , A.B.K., 2019. Permafrost collapse is accelerating carbon release. Nature Astronomy 569, 32-34.


The sudden collapse of thawing soils in the Arctic might double the warming from greenhouse gases released from tundra, warn Merritt R. Turetsky and colleagues.

This much is clear: the Arctic is warming fast, and frozen soils are starting to thaw, often for the first time in thousands of years. But how this happens is as murky as the mud that oozes from permafrost when ice melts.

As the temperature of the ground rises above freezing, microorganisms break down organic matter in the soil. Greenhouse gases — including carbon dioxide, methane and nitrous oxide — are released into the atmosphere, accelerating global warming. Soils in the permafrost region hold twice as much carbon as the atmosphere does — almost 1,600 billion tonnes1.

What fraction of that will decompose? Will it be released suddenly, or seep out slowly? We need to find out.

Current models of greenhouse-gas release and climate assume that permafrost thaws gradually from the surface downwards. Deeper layers of organic matter are exposed over decades or even centuries, and some models are beginning to track these slow changes.

But models are ignoring an even more troubling problem. Frozen soil doesn’t just lock up carbon — it physically holds the landscape together. Across the Arctic and Boreal regions, permafrost is

collapsing suddenly as pockets of ice within it melt. Instead of a few centimetres of soil thawing each year, several metres of soil can become destabilized within days or weeks. The land can sink and be inundated by swelling lakes and wetlands.

Abrupt thawing of permafrost is dramatic to watch. Returning to field sites in Alaska, for example, we often find that lands that were forested a year ago are now covered with lakes2. Rivers that once ran clear are thick with sediment. Hillsides can liquefy, sometimes taking sensitive scientific equipment with them.

This type of thawing is a serious problem for communities living around the Arctic (see ‘Arctic permafrost’). Roads buckle, houses become unstable. Access to traditional foods is changing, because it is becoming dangerous to travel across the land to hunt. Families cannot reach lines of game traps that have supported them for generations.

In short, permafrost is thawing much more quickly than models have predicted, with unknown consequences for greenhouse-gas release. Researchers urgently need to learn more about it. Here we outline how.

Twice the problem

Permafrost is perennially frozen ground. It is composed of soil, rock or sediment, often with large chunks of ice mixed in. About one-quarter of the land in the Northern Hemisphere is frozen in this way. Carbon has built up in these frozen soils over millennia because organic material from dead plants, animals and microbes has not broken down.

Modellers attempt to project how much of this carbon will be released when the permafrost thaws. It is complicated: for example, they need to understand how much of the carbon in the air will be taken up by plants and returned to the soil, replenishing some of what was lost. Predictions suggest that slow and steady thawing will release around 200 billion tonnes of carbon over the next 300 years under a business-as-usual warming scenario3. That’s equivalent to about 15% of all the soil carbon currently stockpiled in the frozen north.

But that could be a vast underestimate. Around 20% of frozen lands have features that increase the likelihood of abrupt thawing, such as large quantities of ice in the ground or unstable slopes2. Here permafrost thaws quickly and erratically, triggering landslides and rapid erosion. Forests can be flooded, killing large areas of trees. Lakes that have existed for generations can disappear, or their waters can be diverted.

Worse, the most unstable regions also tend to be the most carbon-rich2. For example, 1 million square kilometres of Siberia, Canada and Alaska contain pockets of Yedoma — thick deposits of permafrost from the last ice age4. These deposits are often 90% ice, making them extremely vulnerable to warming. Moreover, because of the glacial dust and grasslands that were folded in when the deposits formed, Yedoma contains 130 billion tonnes of organic carbon — the equivalent of more than a decade of global human greenhouse-gas emissions.

How much permafrost carbon might be released with abrupt thawing? As a first step, this year we synthesized results from published studies of abrupt thawing across the permafrost zone. We asked how this type of thawing influences plants, soils and moisture in the ground. The studies revealed patterns of collapse and recovery. This international project was supported by the Permafrost Carbon Network (www.permafrostcarbon.org), part of the multimillion-dollar global Study of Environmental Arctic Change (SEARCH).

Lakes and wetlands are a big part of the problem because they release large amounts of methane, a greenhouse gas that is much more potent than CO25. Erosion from hills and mountains is also problematic: when hillsides thaw and break up, much CO2 is released as material is destabilized, decomposed or washed into streams or rivers6.

We estimate that abrupt permafrost thawing in lowland lakes and wetlands, together with that in upland hills, could release between 60 billion and 100 billion tonnes of carbon by 2300. This is in addition to the 200 billion tonnes of carbon expected to be released in other regions that will thaw gradually. Although abrupt permafrost thawing will occur in less than 20% of frozen land, it increases permafrost carbon release projections by about 50%. Gradual thawing affects the surface of frozen ground and slowly penetrates downwards. Sudden collapse releases more carbon per square metre because it disrupts stockpiles deep in frozen layers.

Furthermore, because abrupt thawing releases more methane than gradual thawing does, the climate impacts of the two processes will be similar7. So, together, the impacts of thawing permafrost on Earth’s climate could be twice that expected from current models.

Stabilizing the climate at 1.5 °C of warming8 requires massive cuts in carbon emissions from human activities; extra carbon emissions from a thawing Arctic make that even more urgent.

Research gaps

Our estimates are rough and need refining. However, they show that understanding abrupt thawing must be a research priority.

First, climate and soil scientists need to find out where the greatest emissions of methane and CO2 will come from. Although we have a good idea of current numbers of thaw lakes and wetlands9, and how many existed in the past10, we need to be able to project where new ones will appear. We also need to know how quickly they will drain as the climate warms.

Second, the erosion of thawed soils on hillsides is poorly understood. Because collapsing slopes are hard to detect using satellites, only a few large-scale studies have been done, often using data from oil exploration or road surveys. Researchers need to establish how much permafrost carbon is displaced and what happens after it has thawed. For example, it is not known how much will stay in the ground or be buried, and how much will enter the atmosphere as a greenhouse gas11,12. And what happens to this material if it flows into rivers, lakes and estuaries?

Third, we need to identify the extent to which plant growth will offset the carbon that is released by permafrost3. Over time, lakes are invaded by wetland plants, and eventually drain and convert back to tundra. Eroded areas are colonized by plants, which helps to stabilize soils and speed their recovery. Researchers need to monitor how thawed ecosystems evolve, the rate at which vegetation stabilizes, and how these plants accumulate biomass. Vegetation also responds to rising CO2 and nutrients, longer growing seasons and changing levels of soil moisture. Modellers will need to predict changing feedbacks between ecological communities and geomorphology as permafrost landscapes transform.

Fourth, the distribution of ice in the ground is the main factor influencing the fate of permafrost carbon. Yet observations of ground ice are sparse. More-widespread geophysical measurements could map pockets of ice below the surface, revealing where it concentrates and how quickly it melts. Machine-learning techniques might even be developed to predict where most ice is buried, by analysing soils and topography at the surface.

Next steps

To plug these knowledge gaps, we have five recommendations.

Extend measurement technology. There should be better tracking of permafrost and carbon across the Arctic, especially in regions undergoing abrupt thawing. It is important to establish baselines of permafrost and ecosystem change against which future measures can be compared. This will require aircraft-based lidar (light detection and ranging, a surveying technique that uses pulsed laser light), drone-based surveys and better algorithms for image analysis.

Fund monitoring sites. River chemistry can be a sensitive indicator of abrupt thawing, but many monitoring stations are being abandoned13. Instead, there should be increased national and international investment in long-term sites that link land-based observations with aquatic and marine measurements. Better recordings of organic matter and nutrients in rivers would shed light on how permafrost plant and microbial communities respond to abrupt and gradual thawing.

Gather more data. Regions that are vulnerable to abrupt thawing need more boreholes, long-term observatories and experiments. Field measurements should quantify how much CO2 and methane is released to the atmosphere as frozen soils are disturbed and recover. Importantly, permafrost researchers and industry groups must deposit all ground-ice data — even if the information is qualitative — in public archives.

Build holistic models. Earth-system models should include the key processes affecting carbon release from permafrost — including how temperature and moisture influence carbon release for a range of climate and vegetation scenarios. Because abrupt thawing occurs at fine spatial scales, detailed process models of these dynamics could be impractical to run directly within Earth-system models. Frameworks must be developed to understand and quantify the effect of these fine-scale processes at the global level.

Improve reports. Policymakers need the best current estimates of the implications of abrupt thawing on climate change. It needs to be considered within the set of unresolved climate feedbacks, as the Intergovernmental Panel on Climate Change (IPCC) did for gradual thawing in its 2018 special report8. The Permafrost Carbon Network is contributing to such efforts, for example by ensuring that abrupt thawing is characterized in the IPCC’s Special Report on the Ocean and Cryosphere in a Changing Climate, which will be released later this year.

We can’t prevent abrupt thawing of permafrost. But we can try to forecast where and when it is likely to happen, to enable decision makers and communities to protect people and resources. Reducing global emissions might be the surest way to slow further release of permafrost carbon into the atmosphere3. Let’s keep that carbon where it belongs — safely frozen in the stunning soils of the north.

References1. Schuur, E. A. G. et al. Nature 520, 171–179 (2015).2. Olefeldt, D. et al. Nature Commun. 7, 13043 (2016).3. McGuire, A. D. et al. Proc. Natl Acad. Sci. USA 115, 3882–3887 (2018).4. Strauss, J. et al. Earth-Sci. Rev. 172, 75–86 (2017).5. Walter Anthony, K. M. et al. Nature Commun. 9, 3262 (2018).6. Abbott, B. W. & Jones, J. B. Glob. Change Biol. 21, 4570–4587 (2015).7. Koven, C. D. et al. Phil. Trans. R. Soc. A 373, 20140423 (2015).8. Rogelj, J. et al. in Global Warming of 1.5 °C (eds Masson-Delmotte, V. et al.) Ch. 2 (IPCC,

2018).9. Nitze, I., Grosse, G., Jones, B. M., Romanovsky, V. E. & Boike, J. Nature Commun. 9, 5423

(2018).

10. Treat, C. C. et al. Proc. Natl Acad. Sci. USA 116, 4822–4827 (2019).11. Vonk, J. E. et al. Geophys. Res. Lett. 40, 2689–2693 (2013).12. Abbott, B. W., Jones, J. B., Godsey, S. E., Larouche, J. R. & Bowden, W. B. Biogeosciences 12,

3725–3740 (2015).13. Laudon, H. et al. Nature Geosci. 10, 324–325 (2017).

Uzhel, A.S., Gorbovskaya, A.V., Zatirakha, A.V., Smolenkov, A.D., Shpigun, O.A., 2019. Manipulating selectivity of covalently-bonded hyperbranched anion exchangers toward organic acids. Part II: Effect of mono- and dicarboxylic amino acids in the internal part of the functional layer. Journal of Chromatography A 1596, 117-123.


Four covalently-bonded hyperbranched anion exchangers based on poly(styrene-divinylbenzene) (PS-DVB) substrate with different structure of the functional layer were prepared using mono- and dianionic amino acids such as glycine, β-alanine, aspartic acid, and glutamic acid in the internal part of the functional layer. Selectivity of all anion exchangers toward weakly retained organic acids was investigated at different temperatures in order to evaluate the effect of the number of carboxylic groups in the functional layer and its hydrophilicity on the separation. It was found that dianionic amino acids used in the first modification cycle of hyperbranching provide the best resolution for mono- and divalent organic acids, which makes the number of carboxylic groups in the structure of amino acid a key factor in the separation of such analytes with covalently-bonded hyperbranched anion exchangers, while the role of amino acid hydrophilicity is not that significant. Stationary phases prepared using aspartic and glutamic acids provided baseline resolution for quinic, glycolic, acetic, lactic, formic, and galacturonic acids, which are not resolved to baseline with modern commercially available anion exchangers; the increase of temperature was found to be favorable for improving the resolution even further.

Valle, B., Dal' Bó, P.F., Mendes, M., Favoreto, J., Rigueti, A.L., Borghi, L., de Oliveira Mendonça, J., Silva, R., 2019. The expression of the Oceanic Anoxic Event 2 (OAE2) in the northeast of Brazil (Sergipe-Alagoas Basin). Palaeogeography, Palaeoclimatology, Palaeoecology 529, 12-23.


Global oceanic anoxic events occurred throughout the Cretaceous and changed the sedimentation patterns in many sedimentary basins around the world. There is still a lack of data and the need to identify new sections affected by these events in the Southern Hemisphere in order to provide insights on the extent of low-oxygen oceanic conditions. This study presents sedimentological, petrographic, and geochemical data from a continuous 439-m-thick well core drilled in the Sergipe-Alagoas Basin. The analytical data suggest that anoxic conditions prevailed at the end of Cenomanian and the beginning of Turonian, being globally correlatable to the Oceanic Anoxic Event 2 (OAE2). The results on the delimitation and extent of the OAE2 in the Sergipe-Alagoas Basin aid to better define the paleoceanographic changes that occurred in the South Atlantic Ocean during OAE2 and provide a new set of data that enables further studies and correlation to other sections distributed worldwide.

van de Kamp, J., Hook, S.E., Williams, A., Tanner, J.E., Bodrossy, L., 2019. Baseline characterization of aerobic hydrocarbon degrading microbial communities in deep-sea sediments of the Great Australian Bight, Australia. Environmental Microbiology 21, 1782-1797.

https://doi.org/10.1111/1462-2920.14559

Exploratory drilling for deep‐sea oil and gas resources is planned for the Great Australian Bight (GAB). There is scant knowledge of the region's benthic ecosystems and no baseline information of the region's indigenous oil degrading bacteria. To address this knowledge gap, we used next generation sequencing (NGS) of three marker genes (alkB, c23o and pmoA) to detect and characterize the microbial communities capable of aerobic hydrocarbon degradation. Unique, highly novel microbial communities capable of degrading hydrocarbons occur in surface sediments at depths between 200 and 2800 m. Clustering at 97% demonstrated differences in community structure with depth, changing most markedly between 400 and 1000 m depth on the continental slope, and identified putative functional ‘ecotypes’ related to depth. Observed differences in community structure showed strong correlations with temperature, other physicochemical properties of the overlying water column and are further modulated by differences in sediment grain size. This study provides important baseline data on hydrocarbon degrading microbial communities prior to the start of petroleum resource extraction. Our data will inform future ecological monitoring of the GAB deep‐sea ecosystem.

van der Sluis, L.G., Reimer, P.J., Ogle, N., 2019. Adding hydrogen to the isotopic inventory—Combining δ13C, δ15N and δ2H stable isotope analysis for palaeodietary purposes on archaeological bone. Archaeometry 61, 720-749.

https://doi.org/10.1111/arcm.12441

Few papers using hydrogen stable isotope analysis for human palaeodietary reconstruction purposes have been published and the usefulness of this additional dietary indicator is highlighted here. The hydrogen stable isotope results provide evidence for the continued exploitation of aquatic resources throughout the prehistory of the Limfjord area in Denmark, which is supported by FRUITS estimates using three (CNH) isotopic proxies. While aquatic dietary input has been identified in Mesolithic and Viking Age individuals before, our results show that, in fact, this continued throughout the periods in between (Neolithic, Bronze and Iron Age), albeit on a small scale.

Vance, S.D., Barge, L.M., Cardoso, S.S.S., Cartwright, J.H.E., 2019. Self-assembling ice membranes on Europa: Brinicle properties, field examples, and possible energetic systems in icy ocean worlds. Astrobiology 19, 685-695.


Brinicles are self-assembling tubular ice membrane structures, centimeters to meters in length, found beneath sea ice in the polar regions of Earth. We discuss how the properties of brinicles make them of possible importance for chemistry in cold environments—including that of life's emergence—and we consider their formation in icy ocean worlds. We argue that the non-ice composition of the ice on Europa and Enceladus will vary spatially due to thermodynamic and mechanical properties that serve to separate and fractionate brines and solid materials. The specifics of the composition and dynamics of both the ice and the ocean in these worlds remain poorly constrained. We demonstrate through calculations using FREZCHEM that sulfate likely fractionates out of accreting ice in Europa and Enceladus, and thus that an exogenous origin of sulfate observed on Europa's surface need not preclude additional endogenous sulfate in Europa's ocean. We suggest that, like hydrothermal vents on Earth, brinicles in icy ocean worlds constitute ideal places where ecosystems of organisms might be found.



Long-chain mid-chain-keto-1-ol positional isomers in sediments provide important information on past environments. Unfortunately, we are unable to assess their full potential since conventional GC–MS analysis of sediment extracts is unable to reliably qualify and quantify long-chain mid-chain-keto-1-ol positional isomers, especially if these are of minor abundance. Here, we use NP-HPLC–APCI-MS to separate these isomers at baseline resolution for a given chain-length, providing a reliable alternative method to detect and quantify these molecules. We detected unknown saturated and unsaturated long-chain mid-chain-keto-1-ols and suggest that the C32:1 keto-ol has the keto-group at the C14 position on the basis of the patterns of abundance and retention times. Based on dissimilarities in isomer composition with that of the long-chain mid-chain diols, obtained from the same analysis, we reject the hypothesis that diagenetic oxidation of the mid-chain diol functionality is the major source of the long-chain mid-chain-keto-1-ols. We rather favor the hypothesis that the keto-ols are predominantly produced by currently uncharacterized source organisms.

Vidal, C., 2019. Pulsar positioning system: a quest for evidence of extraterrestrial engineering. International Journal of Astrobiology 18, 213-234.

https://doi.org/10.1017/S147355041700043X

Pulsars have at least two impressive applications. First, they can be used as highly accurate clocks, comparable in stability to atomic clocks; secondly, a small subset of pulsars, millisecond X-ray pulsars, provide all the necessary ingredients for a passive galactic positioning system. This is known in astronautics as X-ray pulsar-based navigation (XNAV). XNAV is comparable to GPS, except that it operates on a galactic scale. I propose a SETI-XNAV research program to test the hypothesis that this pulsar positioning system might be an instance of galactic-scale engineering by extraterrestrial beings. The paper starts by exposing the basics of pulsar navigation, continues with a critique of the rejection of the extraterrestrial hypothesis when pulsars were first discovered. The core section of the paper proposes lines of inquiry for SETI-XNAV, related to the pulsar distribution and power in the galaxy; their population; their evolution; possible pulse synchronizations; pulsar usability when navigating near the speed of light; decoding galactic coordinates; directed panspermia; and information content in pulses. Even if pulsars are natural, they are likely to be used as standards by ETIs in the galaxy. I discuss possible objections and potential benefits for humanity, whether the research program succeeds or not.

Vieira, A.P., Portela, N.A., Neto, Á.C., Lacerda, V., Romão, W., Castro, E.V.R., Filgueiras, P.R., 2019. Determination of physicochemical properties of petroleum using 1H NMR spectroscopy combined with multivariate calibration. Fuel 253, 320-326.


This paper proposes a methodology to characterize the following petroleum properties: UOP characterization factor (K), nitrogen content, solubility parameter, sulfur content, maximum and minimum pour point, and kinematic viscosity (at 20 °C, 30 °C, 40 °C and 50 °C), in petroleum within a single 1H NMR (proton nuclear magnetic resonance) spectra. Multivariate calibration tools, such as partial least squares (PLS), orthogonal projections to latent structures (OPLS) (with variable

selection), interval PLS (iPLS), synergy interval PLS (siPLS) and model population analysis (MPA), were applied to 138 samples. The models were evaluated by coefficient of determination (R2), root mean square error of prediction (RMSEP), and residuals. In general, model population analysis had better results in the determination of petroleum's physicochemical properties than PLS and OPS. Thus, MPA provided models with better accuracy in the determination of the following properties: UOP characterization factor (0.06), nitrogen content (0.048 wt%), kinematic viscosity at 40 °C (relative error of 21.9%) and pour point (14.58 °C and 19.2 °C, respectively). The sulfur content was estimated with a 0.09 wt% mean error of prediction, using the PLS model, and the solubility parameter with a 1.06 (MPa)1/2 mean error of prediction, using the OPLS model.

Vongsvivut, J., Pérez-Guaita, D., Wood, B.R., Heraud, P., Khambatta, K., Hartnell, D., Hackett, M.J., Tobin, M.J., 2019. Synchrotron macro ATR-FTIR microspectroscopy for high-resolution chemical mapping of single cells. Analyst 144, 3226-3238.

http://dx.doi.org/10.1039/C8AN01543K

Attenuated total reflection Fourier transform infrared (ATR-FTIR) spectroscopy has been used widely for probing the molecular properties of materials. Coupling a synchrotron infrared (IR) beam to an ATR element using a high numerical aperture (NA) microscope objective enhances the spatial resolution, relative to transmission or transflectance microspectroscopy, by a factor proportional to the refractive index (n) of the ATR element. This work presents the development of the synchrotron macro ATR-FTIR microspectroscopy at Australian Synchrotron Infrared Microspectroscopy (IRM) Beamline, and demonstrates that high quality FTIR chemical maps of single cells and tissues can be achieved at an enhanced spatial resolution. The so-called “hybrid” macro ATR-FTIR device was developed by modifying the cantilever arm of a standard Bruker macro ATR-FTIR unit to accept germanium (Ge) ATR elements with different facet sizes (i.e. 1 mm, 250 μm and 100 μm in diameter) suitable for different types of sample surfaces. We demonstrated the capability of the technique for high-resolution single cell analysis of malaria-infected red blood cells, individual neurons in a brain tissue and cellular structures of a Eucalyptus leaf. The ability to measure a range of samples from soft membranes to hard cell wall structures demonstrates the potential of the technique for high-resolution chemical mapping across a broad range of applications in biology, medicine and environmental science.

Voosen, P., 2019. Project traces 500 million years of roller-coaster climate. Science 364, 716-717.


When it opens in June, the revamped fossil hall of the Smithsonian Institution's National Museum of Natural History in Washington, D.C., will be more than a vault of dinosaur bones. It will show how Earth's climate has shifted over the eons, driving radical changes in life, and how, in the modern age, one form of life—humans—is in turn transforming the climate. To tell this story, several Smithsonian scientists initiated an effort to chart Earth's average surface temperature over the past 500 million years or so. But making the chart was unexpectedly challenging, and it has triggered a major research effort to reconstruct the record.

Wagner, S., Fair, J.H., Matt, S., Hosen, J.D., Raymond, P., Saiers, J., Shanley, J.B., Dittmar, T., Stubbins, A., 2019. Molecular hysteresis: Hydrologically driven changes in riverine dissolved organic matter chemistry during a storm event. Journal of Geophysical Research: Biogeosciences 124, 759-774.


Abstract: Hydrological events, driven by rainfall, control the amount and composition of dissolved organic matter (DOM) mobilized through river networks. In forested watersheds, the concentration, composition, and reactivity of DOM exported changes as baseflow transitions to storm flow, with major implications to downstream biogeochemistry. Hysteresis describes an observed difference between in‐stream solute concentration/signal and discharge. By studying the relationship between DOM and stream discharge, we refine our understanding of the environmental and hydrological factors that influence the quantity and quality of stream DOM. The main objective of this study was to track hysteretic changes in riverine DOM molecular composition during storm events. Samples were collected from nested sites within the Passumpsic River catchment (Vermont, USA), a tributary of the Connecticut River. High‐resolution monitoring of fluorescent DOM (via in situ sensors) and automated collection of discrete samples captured short‐term, hydrologically driven variations in DOM concentration and composition. Ultrahigh‐resolution mass spectrometry revealed an enrichment in aliphatic compounds at storm onset, while aromatic and polyphenolic compounds were more enriched at peak discharge. Molecular hysteresis patterns were similar across stream orders, indicating that fresh, terrigenous DOM is quickly shunted downstream, through the river network, during pulses of high discharge.

Plain Language Summary: During storm events, rainfall‐runoff processes mobilize large amounts of dissolved organic matter from the land and through river networks. The relationship between stream discharge and dissolved organic matter quantity and composition can vary over the course of a storm event; this variation is termed hysteresis. We examined hysteresis in a forested New England watershed (Vermont, USA) to better understand the location and timing of dissolved organic matter reactivity in river systems. In‐stream sensors captured high‐frequency, storm‐driven changes in dissolved organic matter quantity. Discrete water samples were collected across the storm event for molecular analysis of dissolved organic matter. Molecular analyses revealed differences in dissolved organic matter composition between storm onset and peak discharge. Storm events shunt molecularly diverse organic material further downstream, potentially shifting reactivity hotspots from upper to lower reaches of the watershed.

Wakeham, S.G., Lee, C., 2019. Limits of our knowledge, part 2: Selected frontiers in marine organic biogeochemistry. Marine Chemistry 212, 16-46.


The advent of new sampling tools, analytical methods, and data handling capabilities that have been applied to marine chemistry since the 1970s along with coordinated, international and interdisciplinary research programs has led to explosive growth of marine organic biogeochemistry. Here we briefly summarize the history of stepwise growth as illustrated by community-wide workshop reports and symposia, highlighting evolving recommendations for future research put forth in those reports. Following that, we present examples of four frontiers that have been explored recently, focusing as much as possible at the molecular level and on marine water columns: (i) how analytical advances and informatics tools provide new insight into the chemical nature and cycling of dissolved organic matter; (ii) how evolving studies of suspended and sinking particles play an important role in understanding ocean biogeochemistry; (iii) the new symbiosis between marine microbiology, analytical chemistry and organic geochemistry as illustrated by the archaea, their habitats, lipid biomarkers, and influence on geochemical cycles; and (iv) how advances in compound-specific measurements of carbon, nitrogen, hydrogen, and sulfur isotopes shed new light on sources and behavior of marine organic matter. We cite selected recent (primarily the past two decades) research examples as a basis for further reading and to project into the future some aspects of these

research areas that could be further developed. Throughout, we highlight how new analytical and sampling methods allowed these fields to progress.

Walker, S.I., 2019. The new physics needed to probe the origins of life. Nature Astronomy 569, 36-38.

https://www.nature.com/articles/d41586-019-01318-z

Stuart Kauffman’s provocative take on emergence and evolution energizes .

A World Beyond Physics: The Emergence and Evolution of Life Stuart A. Kauffman Oxford University Press (2019)

Among the great scientific puzzles of our time is how life emerged from inorganic matter. Scientists have probed it since the 1920s, when biochemists Alexsandr Oparin and J. B. S. Haldane (separately) investigated the properties of droplets rich in organic molecules that existed in a ‘prebiotic soup’ on the primitive Earth (see T. Hyman and C. Brangwynne Nature 491, 524–525; 2012). Each hypothesized that organic compounds underwent reactions leading to more complex molecules, and eventually to the first life forms.

What was missing then, as now, is a concrete theory for the physics of what life is, testable against experiment — which is likely to be more universal than the chemistry of life on Earth. Decades after Oparin and Haldane, Erwin Schrödinger’s 1944 book What Is Life? (see P. Ball Nature 560, 548–550; 2018) attempted to lay conceptual foundations for such a theory. Yet, more than 70 years and two generations of physicists later, researchers still ponder whether the answers lie in unknown physics. No one has led the charge on these questions quite like Stuart Kauffman.

In the 1980s and 1990s, Kauffman — a complex-systems researcher — developed a highly influential theory for life’s origins, based on molecules that reproduce only collectively, called autocatalytic sets. He posited that if a chemical soup of polymers was sufficiently diverse, these sets would emerge spontaneously as a phase transition — that is, a significant change in state or function, akin to the shift from solid to liquid. The sets function holistically, mutually catalysing the formation of all their molecular members. (His inspiration was advances in the mathematics of networks by Paul Erdős and Alfréd Rényi, who had demonstrated how phase transitions occur in random networks as connectivity is increased.) Now, in A World Beyond Physics, Kauffman elaborates.

His key insight is motivated by what he calls “the nonergodic world” — that of objects more complex than atoms. Most atoms are simple, so all their possible states can exist over a reasonable period of time. Once they start interacting to form molecules, the number of possible states becomes mind-bogglingly massive. Only a tiny number of proteins that are modestly complex — say, 200 amino acids long — have emerged over the entire history of the Universe. Generating all 20020 of the possibilities would take aeons. Given such limitations, how does what does exist ever come into being?

This is where Kauffman expands on his autocatalytic-sets theory, introducing concepts such as closure, in which processes are linked so that each drives the next in a closed cycle. He posits that autocatalysing sets (of RNA, peptides or both) encapsulated in a sphere of lipid molecules could form self-reproducing protocells. And he speculates that these protocells could evolve. Thus, each new biological innovation begets a new functional niche fostering yet more innovation. You cannot predict what will exist, he argues, because the function of everything biology generates will depend on what came before, and what other things exist now, with an ever-expanding set of what is possible next.

Because of this, Kauffman provocatively concludes, there is no mathematical law that could describe the evolving diversity and abundance of life in the biosphere. He writes: “we do not know the relevant variables prior to their emergence in evolution.” At best, he argues, any ‘laws of life’ that do exist will describe statistical distributions of aspects of that evolution. For instance, they might predict the distribution of extinctions. Life’s emergence might rest on the foundations of physics, “but it is not derivable from them”, Kauffman argues.

If biology cannot be reduced to physics, however, is it “beyond physics”, as Kauffman claims? This is an interesting time to work on life’s origins: there is intensive debate in the field about whether current physics is adequate, or whether new principles are necessary. Will a deep understanding of life ultimately come from comprehending how form and function arise from flows of information? Will life be understood only as a planetary-scale process, fundamentally linked to exoplanet sciences? Or will merging theory and experiment lead to new approaches to creating artificial life? Those approaches are being developed as an international effort, which coalesced in the 2015 conference Re-Conceptualizing the Origins of Life, drawing researchers from institutions including the Santa Fe Institute in New Mexico, the Earth-Life Science Institute at the Tokyo Institute of Technology and Arizona State University in Tempe.

Within, not beyond

I agree with Kauffman that life cannot be explained by our current laws of physics, but dispute his argument that the explanation is ‘beyond’ physics. The distinction might be semantic, but it is important.

Physics has already grown far beyond simply describing aspects of reality, such as the very big (astronomy, cosmology), the very small (quantum systems, particle physics) or the human-sized (mechanics, as studied by Galileo Galilei and Isaac Newton). Interesting work is emerging from the study of complexity in areas such as economics, electronics, climate physics, the science of societies and non-equilibrium thermodynamics.

Such cross-disciplinary advances suggest that physics itself should not be defined merely by systems it has described in the past. It is a way to view the world, one that values the most abstract, fundamental and unifying descriptions of reality, from atoms to the Universe.

Within that span is biological and technological complexity in phenomena from humans to cities. So far, this has been the hardest area in which to gain traction from first-principles approaches, because of the density of interactions across components and scales. The question of whether there is a physics of life demands that we consider that all examples of life might at their core be part of the same fundamental phenomenon; otherwise, ‘life’ is not an objective property, but a collection of special cases. This unified view seems to be in line with what Kauffman is after. But it suggests that an explanation might demand new physics.

Statistical power

The unifying thread that explains life could be something statistical, as Kauffman proposes, and still have ‘law-like’ properties. After all, some physical laws are statistical by nature, such as the second law of thermodynamics.

But conventional approaches to life’s origins — such as the ‘RNA world’ and other genetics-first models — cannot yet be formulated in this way. That is because they make many assumptions on the basis of properties that might be unique to the chemistry of life on Earth, such as that RNA is necessary to life’s origins.

The emerging areas of ‘messy chemistry’ and artificial-life approaches to origins research start from bottom-up chemical mixtures with minimal assumptions about what emerging life might look like. (The chemist Lee Cronin, for example, experiments on self-assembly and self-organization in large molecules such as metal oxides.) In this sense, the field is attempting to take an ensemble approach, and could provide new paths for developing theories on the universal principles bridging non-organic matter and life. It might inspire the next conceptual leap.

In a way that only he can, Kauffman has asked the questions we need to solve the mystery of life and its origins. But there is much work for the next generation to do to answer them.



Trichloroethene (TCE) is extensively used as metal degreaser and causes a serious impact on the soil and groundwater environment due to improper disposal and control. Aerobic co-metabolism strategy relying on methane-oxidizing bacteria is quite attractive to bioremediate TCE contaminated site because no toxic intermediates are produced. Methane monooxygenase (MMO) produced by these methanotrophs can transform TCE into unstable TCE epoxides to accelerate the TCE removal rate. To investigate the potential of applying TCE aerobic co-metabolism strategy in Taiwan, methanotrophic consortia from chloroethenes contaminated groundwater were enriched in this study. Their bacterial communities and MMO genes were analyzed. The selected enriched methanotrophic consortia were then used to evaluate the feasibility of TCE aerobic co-metabolism in batch experiments. The bacterial community diversities significantly declined and methane-oxidizing bacteria became dominant after acclimation. Methane was consumed by all methanotrophic consortia during acclimation and, at the same time, the functional genes mxaF, mmoX and pmoA were successfully amplified from all consortia, except for gene mmoX of consortium C, after enrichment. The TCE removal efficiencies of consortium A were between 69.6 and 90.4% which was superior to those of consortium C (64.3–75.1%). It is possible to apply the aerobic co-metabolism strategy to bioremediate TCE contaminated sites in Taiwan.

Wang, J., Ryan, D., Szabries, M., Jaeger, P., 2019. A study for using CO2 to enhance natural gas recovery from tight reservoirs. Energy & Fuels 33, 3821-3827.


A comprehensive study is presented on the interfacial behavior of all participating phases in a scenario of using carbon dioxide (CO2) to enhance the recovery of natural gas in tight sandstone reservoirs. Natural gas condensate is contacted with CO2 at an increasing pressure to determine the minimum miscibility pressure (MMP) by the vanishing interfacial tension method. Close to the MMP at a higher temperature, some compounds of the mixture are extracted, leaving a heavy oil fraction that remains immiscible. As the second reservoir liquid, formation water is extracted by CO2 from a tight sandstone sample and subsequently applied as a sessile drop for assessment of the wetting behavior inside the reservoir in the presence of injected CO2. The contact angle has been observed to increase with increasing CO2 pressure. It has been further observed that the water contact angle on a gas shale increased with increasing CO2 pressure more rapidly. The results suggest that CO2 could clear the gas flow path blocked by water and gas condensate. As a consequence, the recovery of

natural gas would increase. This could also create greater potential for CO2 storage in gas-depleted reservoirs.

Wang, K., Zhang, H., Han, X., Qiu, W., 2019. Sources and burial fluxes of sedimentary organic carbon in the northern Bering Sea and the northern Chukchi Sea in response to global warming. Science of The Total Environment 679, 97-105.


The Arctic and subarctic seas are the major CO2 sink areas on earth. In this study, the vertical variation characteristics of organic carbon, total nitrogen and their ratio (Corg/Nt), stable isotopes δ13C and δ15N, and BIT (branched and isoprenoid tetraether) index of GDGTs (glycerol dialkyl glycerol tetraethers) in combination with 210Pb-dating were used to analyze the changes in the marine and terrestrial sources of organic carbon in the northern Bering Sea (site 1), western Beaufort Sea slope (site 2) and northern Chukchi Sea (site 3). Organic carbon burial fluxes (OCBF) in the context of global warming were also explored at sites 1 and 3. The results showed that organic matter in these sediments were a mixed input of marine and terrestrial sources, and the BIT index and δ13C of site 2 suggested that the terrestrial soil organic matter was dominant. Based on a combination of 210Pb dating and Corg, the sedimentary OCBF at site 1 was 2.29–3.65 mg cm−2 y−1, and at site 3 was 0.00–0.41 mg cm−2 y−1. The temperature anomalies and sea ice changes in the Arctic in the past 100 years were compared with the burial fluxes of the terrestrial organic carbon. At site 1, the results indicated that fast melting of seasonal sea ice led to earlier arrival of ice algae bloom, enhanced zooplankton feeding and reduced carbon burial from 1947 to 2010, and the sudden increase in carbon burial after 2010 was attributed to an increase in primary productivity and terrestrial organic matter input due to an accelerated melting of sea ice. There was a smaller change in marine organic carbon content in site 3, but OCBF increased after a pre-1965 decrease, mainly controlled by terrestrial organic matter input associated with temperature rising and sea ice melting during recent decades.

Wang, L., Longo, W.M., Dillon, J.T., Zhao, J., Zheng, Y., Moros, M., Huang, Y., 2019. An efficient approach to eliminate steryl ethers and miscellaneous esters/ketones for gas chromatographic analysis of alkenones and alkenoates. Journal of Chromatography A 1596, 175-182.


Long-chain alkenones (LCAs) and alkenoates (LCEs) are highly valuable biomarkers for paleotemperature reconstructions. A major problem, however, for accurate quantification of these compounds using gas chromatography (GC) is co-elution with steryl ethers, wax esters, saturated ketones and other numerous mid-polarity compounds frequently encountered in marginal marine and lake sediments. Co-elution during GC separation is prevalent, particularly if the full homologous series of alkenones and alkenoates are to be analyzed. Taking advantage of the presence of two or more double bonds in LCAs and LCEs, the conventional silica gel impregnated with silver nitrate has previously been used to remove co-eluting compounds for LCAs. However, this conventional argentation chromatography is hampered by the extreme instability of silver nitrate, poor reproducibility, low recovery and short lifetime. Here we demonstrate a highly efficient flash chromatographic approach based on silver thiolate chromatographic material (AgTCM) that overcomes the shortcomings of the traditional argentation chromatography and allows repeated sample preparation (up to 62 samples in one test) with little loss in separation efficiency. AgTCM selectively extracts LCAs and LCEs and effectively eliminates co-eluting compounds including steryl ethers and wax esters for the subsequent gas chromatography (GC) analysis. This new method,

therefore, allows low-cost and high-throughput sample preparation for comprehensive quantification of the full homologous series of LCAs and LCEs in marine and lake sediments.

Wang, M., O’Connor, J.K., Xu, X., Zhou, Z., 2019. A new Jurassic scansoriopterygid and the loss of membranous wings in theropod dinosaurs. Nature 569, 256-259.

https://doi.org/10.1038/s41586-019-1137-z

Powered flight evolved independently in vertebrates in the pterosaurs, birds and bats, each of which has a different configuration of the bony elements and epidermal structures that form the wings. Whereas the early fossil records of pterosaurs and bats are sparse, mounting evidence (primarily from China) of feathered non-avian dinosaurs and stemward avians that derive primarily from the Middle–Upper Jurassic and Lower Cretaceous periods has enabled the slow piecing together of the origins of avian flight. These fossils demonstrate that, close to the origin of flight, dinosaurs closely related to birds were experimenting with a diversity of wing structures. One of the most surprising of these is that of the scansoriopterygid (Theropoda, Maniraptora) Yi qi, which has membranous wings—a flight apparatus that was previously unknown among theropods but that is used by both the pterosaur and bat lineages. This observation was not universally accepted. Here we describe a newly identified scansoriopterygid—which we name Ambopteryx longibrachium, gen. et sp. nov.—from the Upper Jurassic period. This specimen provides support for the widespread existence of membranous wings and the styliform element in the Scansoriopterygidae, as well as evidence for the diet of this enigmatic theropod clade. Our analyses show that marked changes in wing architecture evolved near the split between the Scansoriopterygidae and the avian lineage, as the two clades travelled along very different paths to becoming volant. The membranous wings supported by elongate forelimbs that are present in scansoriopterygids probably represent a short-lived experimentation with volant behaviour, and feathered wings were ultimately favoured during the later evolution of Paraves.

Wang, S., Chen, C., Li, K., Shiau, B., Harwell, J.H., 2019. In situ CO2 enhanced oil recovery: Parameters affecting reaction kinetics and recovery performance. Energy & Fuels 33, 3844-3854.


In situ CO2 enhanced oil recovery (ICE) shows great potential for increasing oil field tertiary recovery. Instead of injecting liquid CO2 directly into the oil reservoir, a solution of a CO2-generating agent is injected to deliver CO2 to the targeted zone. Urea is an attractive gas-generating agent for ICE because it has both low price and exceptional stability in brine with elevated divalent cation concentrations. Besides CO2 , urea thermal hydrolysis releases NH3(aq). Both molecules have positive impacts on the tertiary recovery, such as oil swelling, oil viscosity reduction, brine alkalinity increase, and sand surface wettability reversal. Thermal hydrolysis of urea is rapid at 120 °C, but the reaction rate decreases exponentially at lower temperatures. This work compares tertiary recovery from urea hydrolysis at 120 and 80 °C with and without a homogeneous catalyst (NaOH) for the purpose of examining the feasibility of urea-ICE for low-temperature reservoirs. The tertiary recovery was studied and optimized with data from 11 one-dimensional sand pack tests at varying conditions. Since urea hydrolysis produces a reaction intermediate, ammonium carbamate, which is known to precipitate in the presence of divalent cations, brines with elevated calcium concentrations were studied to examine the divalent cation stability of the proposed system. The optimization work included tests with urea concentrations varying from 1 to 35 wt % and different injection strategies and flow rates (0.03–0.3 mL/min). Tertiary oil recovery results of this study show that there are two different optimal concentrations of urea, one that maximizes the volume of tertiary oil produced and another that minimizes the cost per barrel of tertiary oil produced. The urea consumption of the

proposed ICE can be as low as 34 kg/barrel with 2.5 wt % chemical slug, and the tertiary recovery can be as high as 48.3% with 10 wt % chemical injection. The optimal injection strategy was strongly dependent on chemical residence time because the tertiary recovery mechanisms vary with the injected concentrations. The aqueous effluent showed increasing solution pH, approaching pH 10. Based on an high-performance liquid chromatography analysis of the aqueous effluent, the mass balance of different tests was calculated. No adverse effect on tertiary recovery was observed in simulated seawater brines, with up to 1 wt % dissolved divalent salts. At higher levels of divalent ions (Ca2+ 7000 ppm) in a so-called API brine, lower tertiary recovery was observed but there was no evidence of formation damage and tubing blockage. In this work, the proposed ICE system showed superior tertiary recovery performance (48.3%) compared to the most recent efforts by our group (29.5%) as well as similar ICE systems (2.4–18.8%) proposed by others. Results illustrate the economic feasibility and the divalent cation tolerance of the urea-ICE process.

Wang, T., Tian, Z., Tunlid, A., Persson, P., 2019. Influence of ammonium on formation of mineral-associated organic carbon by an ectomycorrhizal fungus. Applied and Environmental Microbiology 85, Article e03007-18.

http://aem.asm.org/content/85/10/e03007-18.abstract

Abstract: The interactions between dissolved organic matter (DOM) and mineral particles are critical for the stabilization of soil organic matter (SOM) in terrestrial ecosystems. The processing of DOM by ectomycorrhizal fungi contributes to the formation of mineral-stabilized SOM by two contrasting pathways: the extracellular transformation of DOM (ex vivo pathway) and the secretion of mineral-surface-reactive metabolites (in vivo pathway). In this study, we examined how changes in nitrogen (N) availability affected the formation of mineral-associated carbon (C) from these two pathways. DOM was extracted from forest soils. The processing of this DOM by the ectomycorrhizal fungus Paxillus involutus was examined in laboratory-scale studies with different levels of ammonium. At low levels of ammonium (i.e., under N-limited conditions), the DOM components were slightly oxidized, and fungal C metabolites with iron-reducing activity were secreted. Ammonium amendments decreased the amount of C metabolites, and no additional oxidation of the organic matter was detected. In contrast, the hydrolytic activity and the secretion of N-containing compounds increased, particularly when high levels of ammonium were added. Under these conditions, C, but not N, limited fungal growth. Although the overall production of mineral-associated organic C was not affected by ammonium concentrations, the observed shifts in the activities of the ex vivo and in vivo pathways affected the composition of organic matter adsorbed onto the mineral particles. Such changes will affect the properties of organic matter-mineral associations and, thus, ultimately, the stabilization of SOM.

Importance: Nitrogen (N) availability plays a critical role in the cycling and storage of soil organic matter (SOM). However, large uncertainties remain in predicting the net effect of N addition on soil organic carbon (C) storage due to the complex interactions between organic matter, microbial activity, and mineral particles that determine the formation of stable SOM. Here, we attempted to disentangle the effects of ammonium on these interactions in controlled microcosm experiments including the ectomycorrhizal fungus P.involutus and dissolved organic matter extracted from forest soils. Increased ammonium levels affected the fungal processing of the organic material as well as the secretion of extracellular metabolites. Although ammonium additions did not increase the net production of mineral-adsorbed C, changes in the decomposition and secretion pathways altered the composition of the adsorbed organic matter. These changes may influence the properties of the organic matter-mineral associations and, thus, the stabilization of SOM.

Wang, T., Xiu, J., Huang, L., Cui, Q., Ma, Y., Miao, J., Yu, L., 2019. A mathematical model for microbial enhanced oil recovery considering reservoir environment and microbial factor. Acta Petrolei Sinica 40, 448-456.


In this study, a 3D three-phase six-component mathematical model is established to fully reflect the microbial flooding process. The components of this model involve oil, gas, water, microbes, nutrients and metabolites. The model comprehensively involves such properties as microbial growth/death, nutrient consumption, metabolite production, chemotaxis, convection-diffusion, oil viscosity reduction, adsorption, desorption and oil-water interfacial tension change. Considering the effect of reservoir environmental factors on the microbial growth model and inconsistent growth rate of microbes on the ground and underground, the microbial growth kinetics equation is improved on a basis of Monod model. Meanwhile, in order to reflect the effect of bacteria on microbial flooding, a microbial factor is introduced into the mechanism of microbial flooding. Based on case studies, this paper conducts an analysis of the microbial growth model, microbe-nutrient mixed solution injection, environmental inhibition coefficient, maximum specific growth rate and microbial factors. The results show that the metabolite concentration calculated by the improved microbial growth kinetics equation is lower than that of Monod model, but the difference in metabolite concentration obtained using the two microbial growth equations has less effect on final oil recovery. With an increase in the injection amount of microbe-nutrient mixed solution, the difference in metabolite concentration and oil recovery in these two microbial growth equations will be improved. The microbial factor has a great impact on microbial flooding, and the absolute error under different microbial factors in oil recovery can reach up to 24.53 %.

Wang, W., Pang, X., Chen, Z., Chen, D., Yu, R., Luo, B., Zheng, T., Li, H., 2019. Statistical evaluation and calibration of model predictions of the oil and gas field distributions in superimposed basins: A case study of the Cambrian Longwangmiao Formation in the Sichuan Basin, China. Marine and Petroleum Geology 106, 42-61.


Superimposed basins are commonly characterized by a complex distribution of oil and gas accumulations. Because they have generally experienced multistage hydrocarbon accumulation and tectonic movement, it is challenging to predict favorable exploration zones in these basins. The exploration of the deep strata of the Sichuan Basin (i.e., a typical superimposed basin), West China, has been unsatisfactory for petroleum prospectors. Therefore, we chose the Cambrian Longwangmiao Formation in the Sichuan Basin as an example to demonstrate the method, i.e., combination of petroleum system elements to quantitatively predict the petroleum favorable exploration zones. Based on the detailed analysis of the hydrocarbon accumulation process, the source rock (S), migration (M), reservoir depositional facies (D), and regional cap rock (C) are the most important elements controlling the formation and distribution of oil and gas accumulations in the studied basin. By studying the functional relationships among these four elements and the distribution of the petroleum accumulations, we determined the accumulation probability related to each element and quantitatively predicted the probability of a favorable hydrocarbon accumulation zone. We built a quantitative model of the reservoir preservation probability based on the statistical relationship between the intensity of the tectonic movement and subsequent destruction of existing oil and gas accumulations. Favorable exploration zones can be determined by overlaying favorable accumulation zones with disturbances associated with the tectonic evolution. The results suggest that the most favorable exploration zones of the Longwangmiao Formation in the Sichuan Basin are distributed in the regions west of Weiyuan and east of Gaoshiti–Moxi, Pengxi–Yilong, and Dazhou–Kaijiang. The production

data for existing fields in the Sichuan Basin show that 87% of the successful wells are in the predicted favorable exploration zones and that the success rate with respect to the prediction of failure wells is 67%. This approach highlights the most prospective exploration areas in superimposed basins, which, in general, is challenging and complex for traditional basin modeling tools.

Wang, W., Wan, T., Becher, H., Kuderova, A., Leitch, I.J., Garcia, S., Leitch, A.R., Kovařík, A., 2019. Remarkable variation of ribosomal DNA organization and copy number in gnetophytes, a distinct lineage of gymnosperms. Annals of Botany 123, 767-781.

https://doi.org/10.1093/aob/mcy172

Introduction: Gnetophytes, comprising the genera Ephedra, Gnetum and Welwitschia, are an understudied, enigmatic lineage of gymnosperms with a controversial phylogenetic relationship to other seed plants. Here we examined the organization of ribosomal DNA (rDNA) across representative species.

Methods: We applied high-throughput sequencing approaches to isolate and reconstruct rDNA units and to determine their intragenomic homogeneity. In addition, fluorescent in situ hybridization and Southern blot hybridization techniques were used to reveal the chromosome and genomic organization of rDNA.

Key results: The 5S and 35S rRNA genes were separate (S-type) in Gnetum montanum, Gnetum gnemon and Welwitschia mirabilis and linked (L-type) in Ephedra altissima. There was considerable variability in 5S rDNA abundance, ranging from as few as ~4000 (W. mirabilis) to >100 000 (G. montanum) copies. A similar large variation was also observed in 5S rDNA locus numbers (two to 16 sites per diploid cell). 5S rRNA pseudogenes were interspersed between functional genes forming a single unit in E. altissima and G. montanum. Their copy number was comparable or even higher than that of functional 5S rRNA genes. In E. altissima internal transcribed spacers of 35S rDNA were long and intrinsically repetitive while in G. montanum and W. mirabilis they were short without the subrepeats.

Conclusions: Gnetophytes are distinct from other gymnosperms and angiosperms as they display surprisingly large variability in rDNA organization and rDNA copy and locus numbers between genera, with no relationship between copy numbers and genome sizes apparent. Concerted evolution of 5S rDNA units seems to have led to the amplification of 5S pseudogenes in both G. montanum and E. altissima. Evolutionary patterns of rDNA show both gymnosperm and angiosperm features underlining the diversity of the group.

Wang, X., Xu, P., 2019. Microbial degradation of nitrogen heterocycles. International Biodeterioration & Biodegradation 142, 170-171.


Nitrogen heterocycles are pollutants that are widely prevalent in various environments and have carcinogenic, mutagenic, and genotoxic properties, making them very hazardous to human health. Biodegradation of heterocycles, especially compounds of the pyrrole type, has been an ongoing focal point of research for decades. This perspective mainly focuses on biodegradation of the recalcitrant tricyclic pyrrole heterocycles of carbazole. The metabolic pathway and degradative molecular mechanism of carbazole degradation have been illustrated in depth. Future research will address the fate of pollutants and the behavior of degradative bacteria in polluted environments. Advances in

synthetic biology will aid in achieving highly efficient degradation of persistent and toxic substances by highly adaptable microbes, and will assist in recovering resource from wastes.

Wang, Y., Liu H., Song, G., Xiong, W., Zhu, D., Zhu, D., Yin, Y., Ding, J., Yang, W., Zhang, L., Zhang, S., 2019. Lacustrine shale fine-grained sedimentary system in Jiyang depression Acta Petrolei Sinica 40, 395-410.


The study on fine sedimentary system of mud shale is the frontier of sedimentology. Taking the fine-grained mud shale from the upper submember of Member 4 and lower submember of Member 3 of Shahejie Formation in Jiyang depression as an example, using core description, thin section observation, geochemical tests and other methods, this paper investigates the fine-grained sedimentary system of lacustrine shale. It is considered that the mud shale from the upper submember of Member 4 and lower submember of Member 3 of Shahejie Formation in Jiyang depression is a product of the combined action of mechanical and biochemical mixed sedimentation under the relatively stable water environment. Based on the basic characteristics of mud shale in this study area mainly composed of allogenic terrestrial clastic rocks outside the basin and authigenic carbonate rocks inside the basin, the sedimentary facies are divided to exogenous facies, hybrid-source facies and the endogenous facies according to the material sources. Furthermore, mainly based on the orderly combination of sedimentary dynamics and lithofacies, in combination with the paleo-topography, the exogenous facies is divided into slope edge subfacies and outer slope subfacies; the hybrid-source facies is divided into inner slope subfacies and deep sag subfacies; the endogenous facies is divided into underwater bulge subfacies and panland subfacies. The sedimentary system is controlled by the evolution of sedimentary environment vertically. As the climate evolves from drought to moisture, the material source injection is enhanced. From bottom to top, endogenous facies, hybrid-source facies, and exogenous facies are developed. In the lateral direction, due to the symmetric supply of material source along the short axis of the basin, the sedimentary facies are characterized by symmetric distribution. From the gentle slope to the steep slope, the exogenous facies, hybrid-source facies, endogenous facies, hybid-source facies, exogenous facies are developed successively. In plane view, controlled by paleo-provenance, paleo-salinity and paleo water depth, the sedimentary facies is roughly distributed around the geometric center of the basin and distributed in a ring-like shape. The endogenous facies is mainly distributed in the underwater bulge and panland, the hybrid-source facies is mainly developed in the semi-deep lake area, and the exogenous facies is mainly distributed on the edge of coarse clastic rock system.

Wang, Y., Liu, L., Zheng, S., Luo, Z., Sheng, Y., Wang, X., 2019. Full-scale pore structure and its controlling factors of the Wufeng-Longmaxi shale, southern Sichuan Basin, China: Implications for pore evolution of highly overmature marine shale. Journal of Natural Gas Science and Engineering 67, 134-146.


Shale gas primarily exists in nanopores in shale as different occurrence phases. Studies on pore structure characterization and its controlling factors are the key to understand shale gas occurrence and gas accumulation mechanism. Mercury intrusion capillary pressure (MICP), low-pressure N2 and CO2 adsorption were applied to quantify pore structure of all sizes for Wufeng-Longmaxi shale from southern Sichuan Basin, China. These shales are currently highly overmature, and their total organic carbon (TOC) contents range from 0.04% to 5.19%. Quartz content is positively correlated with TOC content in the clay-poor shales, whereas it exhibits no correlation with TOC in the clay-rich shales.

Different relationships are likely due to difference in quartz origins, since the clay-poor shales contain more biogenic quartz than the clay-rich shales. Furthermore, multimodal pore size distributions were observed. Total pore volume, ranging from 1.41 to 3.03 cm3/100 g, is mainly provided by pores less than 10 nm in diameter, whereas most of the specific surface area, ranging from 19.55 to 36.64 m2/g, is provided by pores less than 2 nm in diameter. Organic matter contributes mostly to micro- and mesopore development. Clay minerals, mainly illite, also make a contribution to pore structure, especially in the organic-lean shales. The porosity development of micro- and mesopores is also controlled by thermal evolution of organic matter. Micro- and mesopores were developed at the immature to early mature stages due to pore rearrangement, expulsion of liquid hydrocarbon, and dissolution of unstable minerals. The following decrease during the late mature stage was mainly caused by oil and bitumen infill. Both micro- and mesopores were reopened at the postmature stage, which was driven by the secondary cracking of residual oil and bitumen. The final significant decline of micro- and mesopore volumes at the overmature stage was caused by persistent compaction and OM carbonization.



The biogeochemical cycles of iron and dissolved organic matter (DOM) are strongly associated, especially at different oxidation sates. However, the role of iron minerals with different oxidation states in DOM preservation has not been clearly characterized at the molecular level. In this study, we employed electrospray ionization coupled with Fourier-transform ion cyclotron resonance mass spectrometry (ESI-FT-ICR-MS) to investigate the molecular fractionation of DOM by adsorption onto four iron minerals with different oxidation states (ferrihydrite, hematite (α-Fe2O3), iron sulfide (FeS), and pyrite (FeS2)). The sorption capacity (normalized to per gram adsorbent) with respect to DOM was in the order of ferrihydrite > iron sulfide > hematite > pyrite. After normalization by specific surface area, the sorption capacity of ferrihydrite plummeted to the second place and was much lower than that of iron sulfide. The sorptive fractionation of DOM was significant for ferrihydrite and iron sulfide but was not obvious for pyrite. Compounds high in unsaturation and nominal oxidation state of carbon or rich in oxygen were preferentially bound to ferrihydrite and iron sulfide, leaving compounds low in unsaturation or poor in oxygenated groups in solution. For DOM containing abundant oxygen functional groups, hematite may result in stronger sorptive fractionation than iron sulfide. These findings provided new insights into the stability of aromatic and aliphatic carbon with various oxygenated groups coupled to redox iron transformation in soils.

Warren, M., 2019. Biggest Denisovan fossil yet spills ancient human’s secrets. Nature Astronomy 569, 16-17.


Jawbone from China reveals that the ancient human was widespread across the world — and lived at surprising altitude.

Scientists have uncovered the most complete remains yet from the mysterious ancient-hominin group known as the Denisovans. The jawbone, discovered high on the Tibetan Plateau and dated to more than 160,000 years ago, is also the first Denisovan specimen found outside the Siberian cave in which

the hominin was found a decade ago — confirming suspicions that Denisovans were more widespread than the fossil record currently suggests.

The research marks the first time an ancient human has been identified solely through the analysis of proteins. With no usable DNA, scientists examined proteins in the specimen’s teeth, raising hopes that more fossils could be identified even when DNA is not preserved.

“This is fantastic work,” says Katerina Douka, an archaeologist at the Max Planck Institute for the Science of Human History in Jena, Germany, who runs a separate project aiming to uncover Denisovan fossils in Asia. “It tells us that we are looking at the right area.”

Hunting for Denisovans

Until now, everything scientists have learnt about Denisovans has come from a handful of teeth and bone fragments from Denisova Cave in Russia’s Altai Mountains. DNA from these remains revealed that the Denisovans were a sister group to Neanderthals, both descending from a population that split away from modern humans about 550,00–765,000 years ago. And at Denisova Cave, the two groups seem to have met and interbred: a bone fragment described last year belonged an ancient-human hybrid individual who had a Denisovan father and Neanderthal mother.

But many expected that it was only a matter of time before researchers found evidence of Denisovans elsewhere. Some modern humans in Asia and Oceania carry traces of Denisovan DNA, raising the possibility that the hominin lived far away from Siberia. And some researchers think that unclassified hominin fossils from China could be Denisovan.

The latest specimen, described in Nature1, consists of half a lower jaw, with two complete teeth. A monk found it in Baishiya Karst Cave in China in 1980, and passed on to Lanzhou University. But it wasn’t until the 2010s that archaeologist Dongju Zhang and her colleagues began studying the bone.

The team faced a problem. The Denisova Cave remains had all been identified because they still contained some DNA, which could be compared with genetic sequences from other ancient humans. But there was no DNA left in the jawbone.

Instead, the scientists looked for ancient proteins, which tend to last longer than DNA. In dentine from the teeth, they found collagen proteins suitable for analysis. The team compared these with equivalent proteins in groupsincluding Denisovans and Neanderthals, and found that they lined up closest with sequences from Denisovans.

The team were also able to piece together other snippets of information about the individual. One of the teeth was still erupting, for example, leading the authors to speculate that the jawbone belonged to an adolescent.

Previous research2 identified Neanderthal remains using both proteins and DNA — but the success of the latest study could lead to a greater emphasis on getting ancient proteins out of fossils that haven’t yielded DNA, says Chris Stringer, a palaeoanthropologist at the Natural History Museum in London. The method could prove particularly useful for older samples or those from southeast Asia and other warm climates, where DNA degrades quickest.

But the field is still in its early stages, Stringer adds, and ancient-protein analysis currently has a smaller sample of early hominins for comparison than does DNA analysis. “Although it’s certainly very suggestive of a link with the Denisovans, I think I’d like to see bigger samples to really pin that down more,” he says.

Douka agrees: for now, ancient DNA analysis remains the “gold standard” for this kind of work, she says. Although there is no genetic material in the jawbone, Douka wonders whether researchers could still find DNA in the Tibetan cave — perhaps in sediment.

The Roof of the World

The altitude of the new Denisovan’s home — 3,280 metres above sea level — surprised researchers, and helps to solve a mystery about Denisovans’ genetic contribution to modern Tibetans. “It is astonishing that any ancient humans were at that altitude,” says Stringer.

Some Tibetans have a variant of a gene called EPAS1 that reduces the amount of the oxygen-carrying protein haemoglobin in their blood, enabling them to live at high altitudes with low oxygen levels. Researchers3 had thought that this adaptation came from Denisovans, but this was difficult to reconcile with Denisova Cave’s relatively low altitude of 700 metres. The latest study suggests that Denisovans evolved the adaptation on the Tibetan Plateau and passed it to Homo sapiens when the species arrived around 30,000–40,000 years ago, says co-author Frido Welker, a molecular anthropologist at the University of Copenhagen. If Denisovans in Asia were adapted to high altitudes, similar sites could harbour more of their remains.

He points to Sel’Ungur cave in Kyrgyzstan, about 2,000 metres above sea level, where a hominin child’s arm bone was found but did not yield any DNA. “Now I ask myself — maybe that specimen is also a Denisovan and not a Neanderthal, like we usually assume,” says Bence Viola, a palaeoanthropologist at the University of Toronto in Canada.

Re-evaluating fossils

And the fossil is likely to prompt scientists to reconsider the classification of other remains. “We can kind of work ourselves through the fossil record, and link up more and more specimens with the Denisovans,” says Viola.

One candidate is a jawbone known as Penghu 1, which was caught in a fishing net near Taiwan and has many similarities to the latest mandible. Welker and his colleagues hypothesize that this jaw could be Denisovan — but the ultimate proof will come from DNA or protein analysis, says Welker.

Sampling any remains for proteins or DNA is by its nature destructive, so there must good justification for doing so, he adds. “It’s not a light-hearted decision to make.”

References1. Chen, F. et al. Nature https://doi.org/10.1038/s41586-019-1139-x (2019).2. Welker, F. et al. Proc. Natl Acad. Sci. USA 113, 11162–11167 (2016).3. Huerta-Sánchez, E. et al. Nature 512, 194–197 (2014).

Watson, T., 2019. The trickster microbes that are shaking up the tree of life. Nature 569, 322-324.

https://www.nature.com/articles/d41586-019-01496-w

Mysterious groups of archaea — named after Loki and other Norse myths — are stirring debate about the origin of complex creatures, including humans.

Every mythology needs a good trickster, and there are few better than the Norse god Loki. He stirs trouble and insults other gods. He is elusive, anarchic and ambiguous. He is, in other words, the

perfect namesake for a group of microbes — the Lokiarchaeota — that is rewriting a fundamental story about life’s early roots.

These unruly microbes belong to a category of single-celled organisms called archaea, which resemble bacteria under a microscope but are as distinct from them in some respects as humans are. The Lokis, as they are sometimes known, were discovered by sequencing DNA from sea-floor muck collected near Greenland1. Together with some related microbes, they are prodding biologists to reconsider one of the greatest events in the history of life on Earth — the appearance of the eukaryotes, the group of organisms that includes all plants, animals, fungi and more.

The discovery of archaea in the late 1970s led scientists to propose that the tree of life diverged long ago into three main trunks, or ‘domains’. One trunk gave rise to modern bacteria; one to archaea. And the third produced eukaryotes. But debates soon erupted over the structure of these trunks. A leading ‘three-domain’ model held that archaea and eukaryotes diverged from a common ancestor. But a two-domain scenario suggested that eukaryotes diverged directly from a subgroup of archaea.

The arguments, although heated at times, eventually stagnated, says microbiologist Phil Hugenholtz at the University of Queensland in Brisbane, Australia. Then the Lokis and their relatives blew in like “a breath of fresh air”, he says, and revived the case for a two-domain tree.

These newly discovered archaea have genes that are considered hallmarks of eukaryotes. And deep analysis of the organisms’ DNA suggests that modern eukaryotes belong to the same archaeal group. If that’s the case, essentially all complex life — everything from green algae to blue whales — originally came from archaea.

But many scientists remain unconvinced. Evolutionary tree building is messy, contentious work. And no one has yet published evidence to show that these organisms can be grown in the lab, which makes them difficult to study. The debate is still rancorous. Stalwarts on both sides are “very hostile to each other, and 100% believe there’s nothing correct in the other camp”, Hugenholtz says. Some decline to voice an opinion, for fear of offending senior colleagues.

What’s at stake is a deeper understanding of the biological leap that produced eukaryotes: “The biggest thing that happened since the origin of life,” according to evolutionary biologist Patrick Keeling at the University of British Columbia in Vancouver, Canada. Where they came from “is one of the most fundamental questions in understanding the nature of biological complexity”, he says. To answer that question, “we need to resolve who’s related to who”.

Two becomes three

For scientists half a century ago, life on Earth was split between two categories: eukaryotes, living things with cells that contain membrane-wrapped internal structures, such as a nucleus; and prokaryotes, single-celled organisms that generally lack internal membranes. Bacteria were the only prokaryotes that biologists knew about. Then, in 1977, evolutionary biologist Carl Woese and his colleagues described archaea as a third, distinct form of life — one that reached back billions of years2. Life, Woese said, should be divided into three bins rather than two.

He was not without his detractors. In the 1980s, evolutionary biologist James Lake at the University of California, Los Angeles, proposed that eukaryotes are sisters to archaea that he called eocytes, which means dawn cells3,4. The idea evolved into the two-domain scenario.

Lake and Woese fought bitterly over their competing models, culminating in a legendary shouting match in the mid-1980s. Afterwards, Woese “didn’t want to meet with Jim Lake”, says microbiologist Patrick Forterre at the Pasteur Institute in Paris. Lake does not dispute the acrimony.

“That was really quite a debate, and there was an enormous amount of politics,” he says. Woese died in 2012.

Today, the argument over where eukaryotes came from has matured. Many on both sides agree that the origin of eukaryotes probably involved a step known as endosymbiosis. This theory, championed by the late biologist Lynn Margulis, holds that a simple host cell living eons ago somehow swallowed a bacterium, and the two struck up a mutually beneficial relationship. These captive bacteria eventually evolved into mitochondria — the cellular substructures that produce energy — and the hybrid cells became what are now known as eukaryotes.

The nature of the engulfing cell is where the two camps diverge. As the three-domain adherents tell it, the engulfer was an ancestral microbe, now extinct. According to Forterre, it was a “proto-eukaryote” — “neither a modern archaeon nor a modern eukaryote”. In this model, there were several major splits in early evolution. The first happened billions of years ago, when primeval organisms gave rise to both bacteria and an extinct group of microbes. This latter group diverged into archaea and the group that became eukaryotes.

In the two-domain world, however, a primeval organism gave rise to bacteria and archaea. And the organism that eventually swallowed the fateful bacterium was an archaeon. That would make all eukaryotes a sort of overachieving branch of the archaea — or, as some scientists call it, a ‘secondary domain’ (see ‘Domains in debate’).

Scrambled messages

Without a wayback machine for microbes, sorting through these hypo-theses is exceedingly difficult. The fossil record for the earliest eukaryotes is sparse, and examples can be inscrutable. Scientists must rely instead on the records that are written in the genomes of modern organisms, which themselves have been scrambled by the passage of time. “We’re trying to resolve something that happened probably a couple billion years ago, using modern sequence data,” says computational evolutionary biologist Tom Williams at the University of Bristol, UK. It is no easy task.

Current gene-sequencing technologies have pushed the debate forward. Until recently, scientists who sought to identify the bacteria or archaea in a particular habitat had to grow the organisms in the lab. Now, researchers can assess microbial diversity in a sample of water or soil by fishing out the DNA and analysing it using mathematical tools, a technique called meta-genomics. In 2002, scientists knew of two categories (or phyla) of archaea. Today, thanks to metagenomics, the number of groupings has exploded.

Evolutionary scientists have been quick to take advantage of the growing bounty. Using the latest powerful modelling techniques, they have created a forest of evolutionary trees detailing the familial relationships among archaea. The results, in many cases, place eukaryotes within the archaeal ranks.

“The weight of evidence, in our view, really did shift toward the two-domain, eocyte tree,” says Williams. But for some, the debate was still short on data.

Then, in 2015, a group led by Thijs Ettema, an evolutionary microbiologist at Uppsala University in Sweden at the time, published DNA sequences for Lokiarchaeota, found in sediments dredged up five years earlier1. Within two years, Ettema’s team and other researchers had announced the discovery of three new archaeal phyla related to the Lokis5,6. The entire grouping of new phyla was named Asgard after the realm of the Norse gods.

The Asgard archaea are tiny in size, but they have proved to be mighty. They have reinvigorated debate about the true number of life’s domains. And they are providing tantalizing hints about the nature of the cells that gave rise to the first eukaryotes — at least to two-domain proponents.

Like their namesake, Lokiarchaeota and their kin evade easy description. They are unquestionably archaea, but their genomes include a smorgasbord of genes that are similar to some found in eukaryotes. Loki DNA, for example, contains genetic instructions for actins, proteins that form a skeleton-like framework in eukaryotic cells. The genes seemed so out of place that the researcher who spotted them initially worried that contamination was to blame. “I said, ‘Hmm, how is that possible? Can it be that this is really an archaeal genome?’” recalls evolutionary microbiologist Anja Spang at the Royal Netherlands Institute for Sea Research in Texel.

Evolutionary modelling reinforced the tight linkage between the Asgard archaea and eukaryotes. The trees built by Ettema’s team place all eukaryotes in the Asgard grouping5,7.

Now, many researchers are using data from these archaea to formulate a better picture of the eukaryotic precursor. It might already have had some features typical of eukaryotes before it took in the mitochondrial predecessor. “It probably had some very primitive membrane-biology processes going on,” Ettema says.

According to an analysis published this year7, the ancestor of the Asgard archaea probably fed on carbon-based molecules, such as fatty acids and butane. This diet would have generated byproducts that could nourish partner bacteria. Such food-sharing agreements — common among microbes — could have evolved into a more intimate relationship. An archaeon might have snuggled up next to its bacterial partner to ease nutrient exchanges, leading eventually to the ultimate embrace.

Such scenarios still provoke doubts, however. Chief among the unconvinced is Forterre. After combing through the Asgard paper, he and his colleagues published an exhaustive rebuttal8 of the work.

Misleading markers?

In a charge that infuriates Ettema, Forterre and his group suggested that some eukaryotic-like sequences found in the Lokis were a result of contamination. A Loki protein called elongation factor 2, for example, was “likely contaminated by eukaryotic sequences”, Forterre’s team wrote in its critique. Forterre now says he’s uncertain about this point.

But he and his colleagues still stand by their criticism of the Asgard evolutionary trees. Even those who are master tree-builders concede that it is tricky to untangle how organisms living two billion years ago were related to each other. Biologists reconstruct these relationships by modelling how a particular ‘marker’ — usually a protein or a gene — has changed over time in the organisms of interest.

Forterre’s group says that Ettema’s team unintentionally chose misleading markers to build its tree. Forterre and his group did their own tree analysis using two large proteins as markers because, by virtue of their size, big proteins are more likely to record the desired information. The result was a three-domain tree.

Ettema says that the two markers used by Forterre are insufficient for tracking events that took place so long ago — a criticism echoed by other scientists. And when Ettema’s team tried to replicate Forterre’s finding, even with the two proteins Forterre used, the result was still a two-domain tree, he says. Ettema hasn’t published the results.

Ettema chalks up some of the differences to disciplinary background. “Patrick Forterre is a brilliant scientist in his field,” he says, but with the Lokis, “he overstepped his expertise a little bit.” Forterre says that he has some skills in phylogenetics and that his co-authors have more.

Nevertheless, not all two-domain supporters dismiss Forterre’s trees. Williams, for example, is building a tree using the latest analytical tools and folding in new varieties of archaea. He hopes that this effort will help him to understand some of Forterre’s results.

The three-domain tree also has a high-profile ally in microbiologist Norm Pace of the University of Colorado, Boulder, who pioneered some of the methods that are essential for placing microbes on the tree of life. Pace says that over vast spans of time, some markers will undergo change that is difficult to track. Ettema and others use statistical methods to account for such stealthy change, but Pace dismisses them. “Ettema and colleagues claim they can calculate unseen change. I claim that’s a stupid assumption,” Pace says. But the methods are widely used. And Ettema counters that scientists can use various tests to determine whether such changes are affecting their data.

Other scientists are reserving judgement: “Trees change,” is a common refrain. Keeling says he’s “totally on the fence”. And Hugenholtz agrees that “the jury’s out”, although both scientists say they think that the evidence for two domains is growing.

As they wait for the rustling trees to settle, researchers are turning to other lines of evidence that might support a two-domain tree. Bacteria and eukaryotes have one set of lipids in their cell membranes, whereas archaeal membranes contain a different set. A mixture of the two was thought to be unstable. This ‘lipid divide’ has been a sore spot for the two-domain proponents, because it implies that if eukaryotes came from archaea, they would have had to switch from using archaeal lipids to producing bacterial versions.

But the lipid divide no longer looms as large. Last year, Dutch researchers succeeded in engineering bacteria with cell membranes that contain both archaeal and bacterial lipids9. Scientists have also found bacteria in the Black Sea that have genes for making both types of lipid10. Microbes could have had such mixed membranes during the transition from archaea to eukaryotes, says microbiologist Laura Villanueva of the Royal Netherlands Institute for Sea Research, who is a member of the team that studied the Black Sea bacteria.

But analyses of the Asgard archaea, including the Lokis, remain limited. “What people are really waiting for is the isolation of a member of these lineages,” says evolutionary microbiologist Simonetta Gribaldo at the Pasteur Institute. “We need to grab them, we need to culture them.”

Some have sluggish metabolisms and are slow to multiply — “exactly what you do not want if you’re trying to grow an organism”, Ettema says. Only a few other scientists admit to even trying. Microbiologist Christa Schleper at the University of Vienna, who is attempting to culture the Asgards, calls it “the craziest project I’ve ever applied for money for”.

Elusive though the microbes might be, one team has captured what it says are the first images of Asgard organisms. Pictures of one type show rounded cells, each containing a compacted bundle of DNA that resembles that defining feature of all eukaryotes, a nucleus. The images are “intriguing” but inconclusive, says microbiologist Rohit Ghai at the Biology Centre of the Czech Academy of Sciences in České Budějovice, who is a co-author of the preprint containing the images11.

The overall picture is still unclear. In Norse legends, Loki often sows mayhem — and then sets everything right again. As the Lokiarchaeota and their relatives emerge from the shadows, two-domain supporters would like them to settle the long-standing debate over the origin of complex life.

But that could take a while. “When we discovered the Asgard archaea, we thought that would convince everybody,” says Spang with a laugh. “That wasn’t the case.”

References1. Spang, A. et al. Nature 521, 173–179 (2015).2. Woese, C. R. & Fox, G .E. Proc. Natl Acad. Sci. USA 74,5088–5090 (1977).3. Lake, J. A., Henderson, E., Oakes, M. & Clark, M. W. Proc. Natl Acad. Sci. USA 81, 3786–3790

(1984).4. Lake, J. A. Nature 331, 184–186 (1988).5. Zaremba-Niedzwiedzka, K. et al. Nature 541, 353–358 (2017).6. Seitz, K. W., Lazar, C. S., Hinrichs, K.-U., Teske, A. P. & Baker, B. J. ISME J. 10, 1696–1705

(2016).7. Spang, A. et al. Nature Microbiol. http://doi.org/gfxrt3 (2019).8. Da Cunha, V., Gaia, M., Gadelle, D., Nasir, A. & Forterre, P. PLoS Genet. 13, e1006810 (2017).9. Caforio, A. et al. Proc. Natl Acad. Sci. USA 115, 3704–3709 (2018).10. Villanueva, L. et al. Preprint at bioRxiv https://doi.org/10.1101/448035 (2018).11. Salcher, M. M. et al. Preprint at bioRxiv https://doi.org/10.1101/580431 (2019).

Wattripont, A., Baudin, F., de Rafelis, M., Deconinck, J.-F., 2019. Specifications for carbonate content quantification in recent marine sediments using Rock-Eval pyrolysis. Journal of Analytical and Applied Pyrolysis 140, 393-403.


The amount of CaCO3 in sediments and/or sedimentary rocks is usually measured by calcimetry while the nature of the carbonates is determined by X-ray diffraction. Recently, a carbonate recognition method based on the results of Rock-Eval pyrolysis was proposed in 2014 by Pillot et al. [1]. Rock-Eval pyrolysis is also widely used for the characterization of recent sediments. However, later in 2015 Baudin et al. [2] noticed that some of the characteristics of recent sediments tended to produce different results from those of more classical Rock-Eval analyses, causing bias in interpretations.

In this study, the thermal stability of fossil and recent marine carbonated sediments was analyzed to identify differences in carbonate decomposition and to underline the importance of accounting for them in Rock-Eval analyses. The state of calcite preservation in recent marine sediments and sedimentary rocks at temperatures between 400 °C and 600 °C was characterized using different techniques (calcimetry, XRD, SEM imaging, etc.) for better interpretation of data obtained with Rock-Eval.

Our results highlight a clear difference in the range of calcite decomposition temperatures during Rock-Eval analysis: between 550 °C and 775 °C for bulk clayey hemipelagic sediments versus 650 °C–840 °C after the same sediments were rinsed to get rid of the salt. During heating, water and hydroxide anions are released from clay minerals and react with salt crystals to form acid vapor. This acid vapor reacts with carbonates to produce CO2. The chemical decomposition of carbonate starts at temperatures that are lower than the typical range of decomposition temperatures, leading to overestimation of mineral carbon content (overestimation of the S5 peak) and to underestimation of organic carbon content (underestimation of the S4CO2 peak) with the Rock-Eval method. In the absence of clay minerals, such as in recent marine pure carbonate oozes, there is no evidence for this effect. It is therefore essential to prepare and rinse recent clay-rich carbonated sediment samples before Rock-Eval analysis to avoid misinterpretation.

Wen, G., Benson, S.M., 2019. CO2 plume migration and dissolution in layered reservoirs. International Journal of Greenhouse Gas Control 87, 66-79.


In carbon capture and storage (CCS) projects, the presence of layered permeability heterogeneity can strongly affect the migration of the supercritical CO2 plume and CO2 dissolution. By conducting a systematic study of plume migration in layered reservoirs with a wide range of permeability contrast between the layers, we show that the relationship between CO2 plume footprint and permeability contrast has three distinct regimes. For moderate permeability contrasts from 1 to 5, the presence of different layers has little impact on plume migration. As the contrast increases from 5 to 50, the plume footprint decreases progressively. In the event of extreme contrast (>50), the footprint is smallest and independent of the heterogeneity. Overall, the footprint of the plume can vary by more than 2-fold, with large implications for monitoring, access to sites, and regulatory issues. The mass fraction of CO2 dissolution can vary up to 2-fold depending on the degree of heterogeneity. We also show that the common practice of using permeability anisotropy to simulate multiphase flows in layered reservoirs works quite well in terms of plume footprint for permeability anisotropy ratios of up to 25, but large errors occur at more extreme contrasts.

Wen, Z., Jiang, S., Song, C., Wang, Z., He, Z., 2019. Basin evolution, configuration styles, and hydrocarbon accumulation of the South Atlantic conjugate margins. Energy Exploration & Exploitation 37, 992-1008.

https://doi.org/10.1177/0144598719840751

The basins of the South Atlantic passive margins are filled with early rifting stage lacustrine sediments (Barremian, 129?125 Ma), transitional lacustrine and marine sediments (Aptian, 125?113 Ma), and drift stage marine sediments since early Cretaceous (Albian, 113 Ma). The South Atlantic margins can be divided into three segments by the Rio Grande Fracture Zone and the Ascension Fracture Zone according to variations in the basin evolution history and configuration style. The lacustrine shale and marine shale source rocks are developed in the rift stage and drift (post-rift) stage in the South Atlantic passive margins, respectively. The southern segment of the margins is dominated by the lacustrine sedimentary filling in the rifted stage overlain by a thin marine sag system as a regional seal, where the hydrocarbons are mainly accumulated in the structural-stratigraphic lacustrine reservoirs formed in the rift stage. The middle segment developed salty rift-sag-type basins with rift and sag systems and with salt deposited in the transitional intercontinental rift stage, where the lacustrine shale in the lower part of the rifted lacustrine sequence and the marine shale in the lower part of the sag sequence formed in the marine post-rift stage are high-quality source rocks. This segment in the middle is mainly dominated by pre-salt lacustrine carbonate and post-salt marine turbidite plays. The northern segment is characterized by sag-type basins with a narrowly and locally distributed rifted lacustrine system and its overlying widely distributed thick marine sag systems. Gravity-flow (mostly turbidite) marine sandstones as good reservoirs were extensively developed in the sag stage due to the narrow shelf and steep slope. The post-rift marine shales in the lower part of the sag sequence are the main source rocks in the northern segment and the hydrocarbons generated from these source rocks directly migrated to and accumulated in the deep marine turbidite sandstones in the same sag sequence formed in the drift stage. From southern segment to northern segment, source rocks and hydrocarbon accumulations tend to occur in the stratigraphically higher formations. The hydrocarbon accumulations in the southern segment are mainly distributed in the rifted lacustrine sequence while that in the northern segment primarily occur in the post-rift marine sequence.

Westbrook, A.W., Miscevic, D., Kilpatrick, S., Bruder, M.R., Moo-Young, M., Chou, C.P., 2019. Strain engineering for microbial production of value-added chemicals and fuels from glycerol. Biotechnology Advances 37, 538-568.


While the widespread reliance on fossil fuels is driven by their low cost and relative abundance, this fossil-based economy has been deemed unsustainable and, therefore, the adoption of sustainable and environmentally compatible energy sources is on the horizon. Biorefinery is an emerging approach that integrates metabolic engineering, synthetic biology, and systems biology principles for the development of whole-cell catalytic platforms for biomanufacturing. Due to the high degree of reduction and low cost, glycerol, either refined or crude, has been recognized as an ideal feedstock for the production of value-added biologicals, though microbial dissimilation of glycerol sometimes can be difficult particularly under anaerobic conditions. While strain development for glycerol biorefinery is widely reported in the literature, few, if any, commercialized bioprocesses have been developed as a result, such that engineering of glycerol metabolism in microbial hosts remains an untapped opportunity in biomanufacturing. Here we review the recent progress made in engineering microbial hosts for the production of biofuels, diols, organic acids, biopolymers, and specialty chemicals from glycerol. We begin with a broad outline of the major pathways for fermentative and respiratory glycerol dissimilation and key end metabolites, and then focus our analysis on four key genera of bacteria known to naturally dissimilate glycerol, i.e. Klebsiella, Citrobacter, Clostridium, and Lactobacillus, in addition to Escherichia coli, and systematically review the progress made toward engineering these microorganisms for glycerol biorefinery. We also identify the major biotechnological and bioprocessing advantages and disadvantages of each genus, and bottlenecks limiting the production of target metabolites from glycerol in engineered strains. Our analysis culminates in the development of potential strategies to overcome the current technical limitations identified for commonly employed strains, with an outlook on the suitability of different hosts for the production of key metabolites and avenues for their future development into biomanufacturing platforms.

Wild, B., Andersson, A., Bröder, L., Vonk, J., Hugelius, G., McClelland, J.W., Song, W., Raymond, P.A., Gustafsson, Ö., 2019. Rivers across the Siberian Arctic unearth the patterns of carbon release from thawing permafrost. Proceedings of the National Academy of Sciences 116, 10280-10285.


Significance: High-latitude permafrost and peat deposits contain a large reservoir of dormant carbon that, upon warming, may partly degrade to CO2 and CH4 at site and may partly enter rivers. Given the scale and heterogeneity of the Siberian Arctic, continent-wide patterns of thaw and remobilization have been challenging to constrain. This study combines a decade-long observational record of 14C in organic carbon of four large Siberian rivers with an extensive 14C source fingerprint database into a statistical model to provide a quantitative partitioning of the fraction of fluvially mobilized organic carbon that specifically stems from permafrost and peat deposits, and separately for dissolved and particulate vectors, across the Siberian Arctic, revealing distinct spatial and seasonal system patterns in carbon remobilization.

Abstract

Climate warming is expected to mobilize northern permafrost and peat organic carbon (PP-C), yet magnitudes and system specifics of even current releases are poorly constrained. While part of the PP-C will degrade at point of thaw to CO2 and CH4 to directly amplify global warming, another part

will enter the fluvial network, potentially providing a window to observe large-scale PP-C remobilization patterns. Here, we employ a decade-long, high-temporal resolution record of 14C in dissolved and particulate organic carbon (DOC and POC, respectively) to deconvolute PP-C release in the large drainage basins of rivers across Siberia: Ob, Yenisey, Lena, and Kolyma. The 14C-constrained estimate of export specifically from PP-C corresponds to only 17 ± 8% of total fluvial organic carbon and serves as a benchmark for monitoring changes to fluvial PP-C remobilization in a warming Arctic. Whereas DOC was dominated by recent organic carbon and poorly traced PP-C (12 ± 8%), POC carried a much stronger signature of PP-C (63 ± 10%) and represents the best window to detect spatial and temporal dynamics of PP-C release. Distinct seasonal patterns suggest that while DOC primarily stems from gradual leaching of surface soils, POC reflects abrupt collapse of deeper deposits. Higher dissolved PP-C export by Ob and Yenisey aligns with discontinuous permafrost that facilitates leaching, whereas higher particulate PP-C export by Lena and Kolyma likely echoes the thermokarst-induced collapse of Pleistocene deposits. Quantitative 14C-based fingerprinting of fluvial organic carbon thus provides an opportunity to elucidate large-scale dynamics of PP-C remobilization in response to Arctic warming.

Wismann, S.T., Engbæk, J.S., Vendelbo, S.B., Bendixen, F.B., Eriksen, W.L., Aasberg-Petersen, K., Frandsen, C., Chorkendorff, I., Mortensen, P.M., 2019. Electrified methane reforming: A compact approach to greener industrial hydrogen production. Science 364, 756-759.


Abstract: Electrification of conventionally fired chemical reactors has the potential to reduce CO2 emissions and provide flexible and compact heat generation. Here, we describe a disruptive approach to a fundamental process by integrating an electrically heated catalytic structure directly into a steam-methane–reforming (SMR) reactor for hydrogen production. Intimate contact between the electric heat source and the reaction site drives the reaction close to thermal equilibrium, increases catalyst utilization, and limits unwanted byproduct formation. The integrated design with small characteristic length scales allows compact reactor designs, potentially 100 times smaller than current reformer platforms. Electrification of SMR offers a strong platform for new reactor design, scale, and implementation opportunities. Implemented on a global scale, this could correspond to a reduction of nearly 1% of all CO2 emissions.

Editor's Summary: More-efficient heating. Large-scale production of hydrogen through steam reforming directly produces CO2 as a side product. In addition, the heating of reactors through fossil-fuel burning contributes further CO2 emissions. One problem is that the catalyst bed is heated unevenly, which renders much of the catalyst effectively inactive. Wismann et al. describe an electrical heating scheme for a metal tube reactor that improves the uniformity of heating and catalyst usage (see the Perspective by Van Geem et al.). Adoption of this alternative approach could affect CO2 emissions by up to approximately 1% of global emissions.

Witkowski, C.R., Agostini, S., Harvey, B.P., van der Meer, M.T.J., Sinninghe Damste, J.S., Schouten, S., 2019. Validation of carbon isotope fractionation in algal lipids as a PCO2 proxy using a natural CO2 seep (Shikine Island, Japan). Biogeosciences Discussions 2019, 1-18.


Carbon dioxide concentrations in the atmosphere play an integral role in many earth system dynamics, including its influence on global temperature. Long-term trends can provide insights into these dynamics though reconstructing long-term trends of atmospheric carbon dioxide (expressed in

partial pressure; PCO2) remains a challenge in paleoclimatology. One promising approach for reconstructing past PCO2 utilizes isotopic fractionation associated with CO2-fixation during photosynthesis into organic matter (Ɛp). Previous studies have focused primarily on testing estimates of Ɛp derived from species-specific alkenone compounds in laboratory cultures and mesocosm experiments. Here, we analyze Ɛp derived from general algal compounds from sites at a CO2 seep near Shikine Island (Japan), a natural environment with CO2 concentrations ranging from ambient (ca. 310 µatm) to elevated (ca. 770 µatm). We observed strong, consistent δ13C shifts in several algal biomarkers from a variety of sample matrices over the steep CO2 gradient. Of the three general algal biomarkers explored here, namely loliolide, phytol, and cholesterol, Ɛp positively correlates with PCO2 in agreement with Ɛp theory and previous culture studies. PCO2 reconstructed from the Ɛp of general algal biomarkers show the same trends throughout, as well as the correct control values, but with lower absolute reconstructed values than the measured values at the elevated PCO2 sites. Our results show that naturally-occurring CO2 seeps may provide useful testing grounds for PCO2 proxies and that general algal biomarkers show promise for reconstructing past PCO2.

Wright, M.T., McMahon, P.B., Landon, M.K., Kulongoski, J.T., 2019. Groundwater quality of a public supply aquifer in proximity to oil development, Fruitvale oil field, Bakersfield, California. Applied Geochemistry 106, 82-95.


Due to concerns over the effects of oil production activities on groundwater quality in California, chemical, isotopic, dissolved gas and age-dating tracers were analyzed in samples collected from public-supply wells and produced-water sites in the Fruitvale oil field (FVOF). A combination of newly collected and historical data was used to determine whether oil formation fluids have mixed with groundwater used for public supply and what the potential pathways for the migration of oil formation fluids into groundwater may be. Stable isotopes of water (δ2H and δ18O) and age dating (3H, 3Hetrit, SF6 and 14C) tracers in groundwater samples were consistent with the Kern River being the main source of recharge to aquifers. The distribution of major ion concentrations and pH with distance from the Kern River indicate that natural processes were the primary controls on groundwater salinity. Two of 14 groundwater samples had δ13C-DIC values (−2.4 to +1.9 per mil) consistent with mixtures of <1 to about 9 percent oil-field water. Concentrations of TDS in groundwater samples were generally much lower (129–1,200 milligrams per liter (mg/l), median 216 mg/l) than produced water samples (586–24,930 mg/l, median 2,717 mg/l), suggesting that any mixing of oil-field water with groundwater has not significantly affected groundwater salinity. Trace concentrations of thermogenic methane were detected in three groundwater samples that did not have dissolved inorganic or isotopic indicators consistent with mixing of oil-field water, suggesting that stray gases may have migrated from the subsurface via preferential pathways such as leaky well bores into groundwater aquifers. Low concentrations of petroleum hydrocarbons were detected in samples that also contained anthropogenic VOCs and components of post- and pre-1950s recharge, indicating that petroleum hydrocarbons could have come from subsurface and/or surface sources. Overall, the results of this study indicated that groundwater currently used for public supply in the FVOF was of good quality with little, if any, effects from oil production activities. This may be due in part to the relatively rapid flushing of the aquifer system by recharge from the Kern River.

Wu, S., Zhu, R., Yang, Z., Mao, Z., Cui, J., Zhang, X., 2019. Distribution and characteristics of lacustrine tight oil reservoirs in China. Journal of Asian Earth Sciences 178, 20-36.


Lacustrine tight oil resources in China are significant exploration targets, similar to the marine tight oil resources in North America, while there are clear differences in terms of the forming environment, as well as reservoir properties of these two systems. In this study, the geological characteristics of lacustrine tight rocks are discussed, including the distribution, petrology, storage space, and movable fluid saturation. The tight rocks are consisted of tight sandstone, tight carbonate rock, tight peperite, and tight sedimentary tuff, in which intergranular pores and dissolved pores with the dimensions of 30–900 nm are mainly dominated by the storage space. The oil saturation typically exceeds 50% and the oil mobility is basically controlled by pore-throats with diameter less than 1 μm. These four types of reservoirs show different potentials for tight oil, in which tight sandstone plays in the Ordos Basin and the Songliao Basin are taken as the preferred targets into account for exploration and development. Although the distribution area, physical properties, and mobility of lacustrine tight oil in China are not as good as those of tight oil in North America, the lacustrine reservoirs are often stacked in multiple layers, resulting in a great thickness, and possess relatively high oil saturation, making them producible and commercially viable. Fluid properties are critical to effectively recovery of tight oil, and more comprehensive geological evaluation on fluid mobility should be undertaken.

Wu, S., Zou, C., Ma, D., Zhai, X., Yu, H., Yu, Z., 2019. Reservoir property changes during CO2–brine flow-through experiments in tight sandstone: Implications for CO2 enhanced oil recovery in the Triassic Chang 7 Member tight sandstone, Ordos Basin, China. Journal of Asian Earth Sciences 179, 200-210.


The effects of supercritical CO2 (ScCO2) on reservoir property changes of the Chang 7 Member tight sandstones of the Yanchang Formation, Ordos Basin, China, were investigated using CO2–brine flow-through experiments, in conjunction with detailed rock and fluid characterization (pre- and post-experiment) using X-ray diffraction mineral analysis, 3D computed tomography scanning, high-resolution scanning electron microscopy, and inductively coupled plasma–atomic emission spectrophotometry. An in situ 3D model was developed to define porosity–mineral evolution. Experiments on three contrasting samples show that minerals such as potassium (K) feldspar, albite, and calcite are variably dissolved during CO2–brine–mineral interactions. The dissolution, migration, and re-precipitation of clay minerals are common and are characterized by the dissolution of chlorite and the re-precipitation of kaolinite, calcium montmorillonite, and sodium montmorillonite. The original chlorite–kaolinite framework of the host rocks was destroyed. Precipitated and re-migrated clay particles (e.g., kaolinites and smectites) that were released by the dissolution accumulated in pore throats, resulting in changes to the pore system and in the physical properties of the host rocks. Physical property change pathways vary among the studied samples, with porosity being reduced by 4.5% and 12.8% or increased by 13.7% by the end of the experiments. Permeability reduction was 33.3%–81.2% and is positively correlated to host rock clay mineral content. The influence of the type and content of clay minerals on porosity requires further evaluation. The findings of the study have implications for the large-scale injection of CO2 into reservoirs during enhanced oil recovery programs and for carbon capture, utilization, and storage programs.

Wu, T., Xu, J., Liu, J., Guo, W.-H., Li, X.-B., Xia, J.-B., Xie, W.-J., Yao, Z.-G., Zhang, Y.-M., Wang, R.-Q., 2019. Characterization and initial application of endophytic Bacillus safensis strain ZY16 for improving phytoremediation of oil-contaminated saline soils. Frontiers in Microbiology 10, 991. doi: 10.3389/fmicb.2019.00991.


Hydrocarbon-degrading and plant-growth-promoting bacterial endophytes have proven useful for facilitating the phytoremediation of petroleum-contaminated soils with high salinity. In this study, we identified Bacillus safensis strain ZY16 as an endophytic bacterium that can degrade hydrocarbons, produce biosurfactants, tolerate salt, and promote plant growth. The strain was isolated from the root of Chloris virgata Sw., a halotolerant plant collected from the Yellow River Delta. ZY16 survived in Luria-Bertani (LB) broth with 0–16% (w/v) sodium chloride (NaCl) and grew well in LB broth supplemented with 0–8% NaCl, indicating its high salt tolerance. The endophytic strain ZY16 effectively degraded C12–C32 n-alkanes of diesel oil effectively, as well as common polycyclic aromatic hydrocarbons (PAHs) under hypersaline conditions. For example, in mineral salts (MS) liquid medium supplemented with 6% NaCl, ZY16 degraded n-undecane, n-hexadecane, n-octacosane, naphthalene, phenanthrene, and pyrene, with degradation percentages of 94.5%, 98.2%, 64.8%, 72.1%, 59.4%, and 27.6%, respectively. In addition, ZY16 produced biosurfactant, as confirmed by the oil spreading technique, surface tension detection, and emulsification of para-xylene and paraffin. The biosurfactant production ability of ZY16 under hypersaline conditions was also determined. Moreover, ZY16 showed plant-growth-promoting attributes, such as siderophore and indole-3-acetic acid (IAA) production, as well as phosphate solubilization. To assess the enhanced phytoremediation of saline soils polluted by hydrocarbons and the plant-growth-promotion ability of ZY16, a pot trial with and without inoculation of the endophyte was designed and performed. Inoculated and non-inoculated plantlets of C. virgata Sw. were grown in oil-polluted saline soil, with oil and salt contents of 10462 mg/kg and 0.51%, respectively. After 120 days of growth, significant enhancement of both the aerial and underground biomass of ZY16-inoculated plants was observed. The soil total petroleum hydrocarbon degradation percentage (a metric of phytoremediation) after incubation with ZY16 was 63.2%, representing an elevation of 25.7% over phytoremediation without ZY16 inoculation. Our study should promote the application of endophytic B. safensis ZY16 in phytoremediation by extending our understanding of the mutualistic interactions between endophytes and their host plants.

Wu, X.-J., Pei, S.-W., Cai, Y.-J., Tong, H.-W., Li, Q., Dong, Z., Sheng, J.-C., Jin, Z.-T., Ma, D.-D., Xing, S., Li, X.-L., Cheng, X., Cheng, H., de la Torre, I., Edwards, R.L., Gong, X.-C., An, Z.-S., Trinkaus, E., Liu, W., 2019. Archaic human remains from Hualongdong, China, and Middle Pleistocene human continuity and variation. Proceedings of the National Academy of Sciences 116, 9820-9824.


Significance: Human evolution through the Middle to the Late Pleistocene in East Asia has been seen as reflecting diverse groups and discontinuities vs. a continuity of form reflecting an evolving population. New Middle Pleistocene (∼300,000 y old) human remains from Hualongdong (HLD), China, provide further evidence for regional variation and the continuity of human biology through East Asian archaic humans. The HLD 6 skull is notable for its low and wide neurocranial vault and pronounced brow ridge, but less projecting face and modest chin. Along with the isolated teeth, the skull provides morphologically simple teeth with reduced or absent third molars. The remains foreshadow changes evident with modern human emergence, but primarily reinforce Old World continuity through Middle to Late Pleistocene humans.

Abstract: Middle to Late Pleistocene human evolution in East Asia has remained controversial regarding the extent of morphological continuity through archaic humans and to modern humans. Newly found ∼300,000-y-old human remains from Hualongdong (HLD), China, including a largely complete skull (HLD 6), share East Asian Middle Pleistocene (MPl) human traits of a low vault with a frontal keel (but no parietal sagittal keel or angular torus), a low and wide nasal aperture, a pronounced supraorbital torus (especially medially), a nonlevel nasal floor, and small or absent third

molars. It lacks a malar incisure but has a large superior medial pterygoid tubercle. HLD 6 also exhibits a relatively flat superior face, a more vertical mandibular symphysis, a pronounced mental trigone, and simple occlusal morphology, foreshadowing modern human morphology. The HLD human fossils thus variably resemble other later MPl East Asian remains, but add to the overall variation in the sample. Their configurations, with those of other Middle and early Late Pleistocene East Asian remains, support archaic human regional continuity and provide a background to the subsequent archaic-to-modern human transition in the region.



For purposes of locating kerogen/organic matter and pores in SEM images of shale samples, we tested an automated SEM-image segmentation workflow involving feature extraction followed by machine learning. The proposed segmentation workflow is an alternative to threshold-based and object-based segmentation. For each pixel in the SEM image, sixteen features are generated and then fed to a random forest classifier to determine the presence of four rock components, namely (1) pore/crack, (2) rock matrix including clay, calcite and quartz, (3) pyrite, and (4) organic/kerogen components. Extraction of the 16 features for each pixel in a 2058 (pixel) by 2606 (pixel) SEM image requires approximately 5 s on a conventional desktop configuration. The most important features for the desired segmentation are wavelet transforms, Gaussian blur and difference of Gaussians. The random-forest classifier was trained using only 705, 2074, 17373, and 15,000 pixels for the pore/crack, organic/kerogen, rock matrix, and pyrite components, respectively. Training of the classifier was accomplished in approximately 7 s. The proposed segmentation methodology can segment one 2058 (pixel) by 2606 (pixel) SEM image in approximately 30 s. For purposes of validation of the segmentation method, 5121, 4725, 4815, and 4775 pixels were used for the pore/crack, organic/kerogen, rock matrix, and pyrite components, respectively, where 1 pixel covers 100 nm2. Despite the limited number of pixels used for training, the performance of the trained classifier, quantified in terms of overall F1 score, on the validation dataset was higher than 0.9. The newly developed method is significantly more reliable and robust in comparison to the popular histogram thresholding and object-based segmentation methods, especially for the matrix and pyrite components in shale samples.

Xu, J., Cui, C., Feng, H., You, D., Wang, H., Li, B., 2019. Marine radar oil-spill monitoring through local adaptive thresholding. Environmental Forensics 20, 196-209.

https://doi.org/10.1080/15275922.2019.1597781

Marine oil spills affect the environment, economy, and quality of life for coastal inhabitants. This article presents a method of X-band marine radar oil-spill identification by considering the marine radar images of the 2010 Dalian 7-16 accident. The Prewitt operator was improved and a linear interpolation was proposed to suppress co-channel interferences. In addition, a model of a gray-intensity-correcting matrix is proposed to smooth a whole image, thus displaying the oil film more intuitively. Furthermore, a contrast-limited adaptive histogram equalization method was used to increase the contrast inside and outside the oil film. Moreover, the local adaptive thresholding method was improved to segment the oil spills. The results show that the proposed method is an improvement on similar previous approaches for this task when employing X-band marine radar images. The proposed method can provide technical and theoretical bases for emergency response, damage assessment, and liability identification of oil spills.



Liuhuanggou bituminous coal (LBC) and its extraction residue (ER) were thermally dissolved sequentially in cyclohexane, toluene, and ethanol at 300 °C to obtain soluble portions (SPs) 1–3 (SP1-SP3) from the thermal dissolution (TD) In the total yield (TY) of 10.4% and SPs I-III (SPI-SPIII) from the TD in the TY of 4.9%, respectively. The SPs were analyzed by multiple analytical tools, including gas chromatograph/mass spectrometer (GC/MS), quadrupole exactive orbitrap mass spectrometer (QEOTMS), and Fourier transform infrared spectrometer. The analysis with GC/MS shows that normal alkanes are the most abundant in SPI, while arenes are predominant in SP1, SP2, and SPII. According to the analysis with QEOTMS, abundant heteroatom-containing organic species were concentrated into SP3 and SPIII with molecular masses of 150–750 u. The relative contents of N1 and N1O1 species are predominantly high in SPIII and SP3, respectively.



Compared with the studies of nanoscale pores in shale, coal, and tight sandstone, studies associated with lacustrine tight carbonate nanoscale pores and their control mechanisms, particularly quantitative studies combining reservoir evaluation and geochemistry, remain scarce. To address this disparity, lacustrine tight carbonate samples collected from the Jurassic Da'anzhai Member in the central Sichuan Basin of China were quantitatively investigated.

Similar to other unconventional reservoirs, lacustrine tight carbonate reservoirs contain well-developed intraparticle pores, interparticle pores, and micro-cracks with nanoscale storage spaces that dominate the full-scale reservoirs. The relatively small pores (3–5 nm) make a dominant contribution to the nanoscale storage space. Isotherms and hysteresis loops are Type II and Type H3, respectively, indicating wedge-shaped pores. However, the hysteresis loops indicate more dead-end pores, larger pores, and more complex microstructures than those found in other unconventional reservoirs.

The mineral in lacustrine carbonate provides a link between the reservoir and the formation environment. Strong paleo-weathering, low salinity, a humid (rainy) paleo-climate and poor hydrodynamic conditions are favorable to improve the storage spaces and terrestrial mineral contents but harmful to the formation of authigenic minerals. Terrestrial minerals, including primarily quartz, clay, and dolomite, have well-developed nanoscale pores and are positively correlated with the nanoscale storage space, whereas authigenic minerals, primarily calcite, have strong cementation and filling effects and are negatively correlated with the nanoscale storage space.

Xu, Z., Liu, L., Liu, B., Wang, T., Zhang, Z., Wu, K., Feng, C., Dou, W., Wang, Y., Shu, Y., 2019. Geochemical characteristics of the Triassic Chang 7 lacustrine source rocks, Ordos Basin, China: Implications for paleoenvironment, petroleum potential and tight oil occurrence. Journal of Asian Earth Sciences 178, 112-138.


The fact that high-quality lacustrine source rocks (generally shale and mudstone) control the formation and distribution of conventional and unconventional oil and gas reservoirs in lacustrine basins has been well-accepted in petroleum exploration and exploitation. Taking the Chang 7 lacustrine source rocks in the Ordos Basin as an example, several points having been reached are as follows. (1) The Chang 7 source rocks possess an excellent source rock potential, and the shales hold a better potential than the mudstones. (2) The paleoenvironments of the Chang 7 source rocks were sub-reducing to sub-oxidizing conditions and fresh- and brackish-water depositional environments with a maximum water depth of 150 m. The organic matter origins of the source rocks are mainly plankton, algae, bacteria and other aquatic microorganisms. (3) The beginning time of the oil generation of the Chang 7 source rocks is at 165 Ma, and the peak oil generation occurred during 115–95 Ma. The cumulative amounts of oil generation are up to 4711 × 103 t/km2 and the ratios of peak generation amounts to cumulative generation amounts are >50%. The beginning timing and peak generation timing of the shales are earlier than those of the mudstones, respectively, and the cumulative oil generation amount of the shales is higher than that of the mudstones, indicating a better oil generation potential of the shales. (4) Due to the more remained oil possessed in the shales, the hydrocarbon expulsion threshold of the Chang 7 shales (2560 m) is deeper than that of the Chang 7 mudstones (2080 m). (5) The occurrences of the Chang 8–6 tight oils are predominantly controlled by the outer boundary of the Chang 7 source rocks distribution, while the transition areas between thickness, TOC, and Ro high value centers are the accumulation and enrichment zones. The Chang 7 shales controlled the occurrence of the Chang 8 tight oil reservoirs and the Chang 7 mudstones controlled the occurrence of the Chang 7 and Chang 6 tight oil reservoirs.

Yang, L., Tang, L., Li, H., Wang, L., Zhang, Y., 2019. Unique microbial communities inhabiting underground seawater in an intertidal area utilized for industrialized aquaculture, as compared with the coastal water. Geomicrobiology Journal 36, 483-491.

https://doi.org/10.1080/01490451.2019.1571128

In recent decades, the decline of coastal water quality has promoted the birth of a new industrialized aquaculture mode in China, which involves the cultivation of organisms using underground seawater extracted from various depths below the intertidal zone. In view of the special physicochemical characteristics of underground seawater, the microbial community in this environment has attracted interest. In this study, the microbial community in the underground seawater of an intertidal area of the Qingdao coast of China was investigated. Compared with the upper coastal water, the underground seawater displayed lower numbers of microorganisms (2.7 ± 0.3 × 105 cells mL−1 in underground seawater vs. 5.3 ± 0.4 × 105 cells mL−1 in upper coastal seawater) but displayed much higher microbial diversity. At the phyla level, Proteobacteria, Bacteroidetes, Cyanobacteria, and Actinobacteria inhabited both environments, whereas bacteria in the phyla Planctomycetes, Deferribacteres, and Nitrospirae were recovered only from the underground seawater. Eighty-nine percent of the OTUs in the underground seawater were environmental specific. Furthermore, compared with coastal water, underground seawater displayed significant lower (p < 0.05) concentration of NH3-N, NO2-N, PO4-P, and DOC-C, and contained fewer potentially harmful pathogens (e.g., Verrucomicrobia/Opitutae) and more denitrifying bacteria (e.g., Shewanella denitrificans), thus making it more suitable for aquaculture.

Yang, S., Hu, W., Wang, X., Jiang, B., Yao, S., Sun, F., Huang, Z., Zhu, F., 2019. Duration, evolution, and implications of volcanic activity across the Ordovician–Silurian transition in the Lower Yangtze region, South China. Earth and Planetary Science Letters 518, 13-25.


Volcanism provides a reliable record of local and global tectonic events and substantially influences both modern and ancient environments, climates, and the evolution of life. The Ordovician–Silurian (O–S) transition is a special period because intensive volcanism occurred globally, including in the Yangtze region of South China. Volcanic events during this period are a symptom of plate tectonic behaviour and are thought to be responsible for the remarkable changes in climate in the early Palaeozoic, though the relationships between these events remain unclear and controversial. Coeval igneous rocks and volcanic sediments (VS) are primarily used to resolve this issue. However, limited studies have been performed on VS from the O–S transition in South China. Recently, a typical VS-bearing section was found in the Lower Yangtze region, which contains ∼100 thin, interbedded volcanic ash layers across the O–S transition. Detailed petrographic and geochemical analyses of the volcanic ashes were conducted to determine their isotopic ages, magma sources, evolutionary processes, and tectonic settings. Our preliminary results suggest that volcanic eruptions in South China lasted for more than 22 Ma across the O–S boundary, from ∼449.3 ± 3.6 to 427.6 ± 4.1 Ma, where 445.14 Ma is the lowermost graptolite biozone for Metabolograptus extraordinarius, as well as the initiation of the Late Ordovician mass extinction (LOME) event in the Yangtze region. The evolutionary history of the parental magma was constructed from a depleted mantle source in the early stage and from a crustal source in the late stage, with several transitional features in the middle. The mantle source and arc-related geochemical indicators for the volcanic ashes support the disputed “subduction-collision orogeny” model. We propose that the strong volcanism in South China, accompanied by volcanism in numerous other regions worldwide, was an important trigger for the LOME and was likely responsible for oceanic 87Sr/86Sr fractionation and other climatic changes during the O–S transition.

Yang, S., Schulz, H.-M., Schovsbo, N., Mayanna, S., 2019. The organic geochemistry of “Kolm”, a unique analogue for the understanding of molecular changes after significant uranium irradiation. International Journal of Coal Geology 209, 89-93.


The highly uraniferous and organic-rich material which occurs as small lenticular nodules in the Upper Cambrian Alum Shale Formation of middle Sweden is known as “Kolm”. The uranium contents in Kolm samples range from 2000 ppm to 6000 ppm (>100 times higher than typical shale), making the organic matter one of the most irradiated in the geological world with an exposure time of >500 Myr. Here, we show that uranium is mostly enriched on the surface of various minerals, instead of being bound to the organic matter. Although Kolm formation predates the evolution of advanced plants and the organic matter is marginally mature, thermovaporisation and pyrolysis products are exclusively composed of gaseous and low-molecular aromatic compounds. The kerogen structure is extremely heterogeneous, and rare bitumen can be extracted although the TOC content of the Kolm sample is 62 wt%. These features are attributed to the irradiation effects of uranium which resulted in radiolytic bond breaking, aromatisation, and polymerisation of the organic matter. The organic-uranium interactions in the investigated Kolm sample shed new light on unexpected phenomena while petroleum exploration.

Yang, X., Zhao, Y., Li, W., Li, R., Wu, Y., 2019. Unveiling the pyrolysis mechanisms of hemicellulose: Experimental and theoretical studies. Energy & Fuels 33, 4352-4360.


Pyrolysis of lignocellulosic biomass is a sustainable and low-cost technology for the production of bio-oil and valued-added chemicals. The present study aims to develop a fundamental and reasonable mechanistic model for hemicellulose pyrolysis. Thermogravimetric analysis–Fourier transform infrared spectroscopy and pyrolysis–gas chromatography/mass spectrometry were performed to investigate the formation mechanisms of the main products, and the density functional theory study was used to find the most rational pathway. A detailed mechanistic model for hemicellulose pyrolysis was developed by using O-acetyl-4-O-methylglucuronoxylan as the model compound. As a result, the energy barriers of the formation of anhydrosugars, low molecular weight products, gas, and furfural were obtained. The study is able to explain the fast pyrolysis behavior and provide a basis for developing models that can predict the yields of products formed in different conditions.

Yang, Y., Liao, J., Mo, Q., Chang, L., Bao, W., 2019. Evolution of physical and chemical structures in lignite during dewatering process and their effects on combustion reactivity. Energy & Fuels 33, 3891-3898.


The Inner Mongolia lignite was selected as the feedstock and dewatered by hydrothermal, fixed-bed, and microwave upgrading techniques. The physicochemical structures of the raw coal and dewatered coal samples were determined by N2 adsorption, Fourier transform infrared, and chemical titration methods. The combustion behavior of coals was investigated by thermogravimetric analyzer, and the results demonstrated that the combustion reactivity of the dewatered coals was enhanced. The apparent activation energies of the coal samples were obtained from nonisothermal single heating rate method, and the results illuminated that the combustion process of these coals could be divided into three stages according to the variations of their apparent activation energies. Those variations were used as the medium to investigate the correlations between combustion reactivity parameters and physicochemical structures. It was found that at stage I of the combustion process, the ignition temperature of the coal was mainly affected by intrinsic chemical reactivity; at stage II, the maximum combustion reaction rate of the coal was affected by intrinsic chemical reactivity and specific area diffusion, and the temperature corresponding to the maximum combustion reaction rate was mainly affected by intrinsic chemical reactivity; and at stage III, the burnout temperature was affected by intrinsic chemical reactivity, and the overall reaction rate was controlled by gas diffusion rate.

Yang, Y., Mai, W., Gao, J., Hu, Z., Xu, J., Zou, S., 2019. An in-needle solid-phase microextraction device packed with etched steel wires for polycyclic aromatic hydrocarbons enrichment in water samples. Journal of Separation Science 42, 1750-1756.

https://doi.org/10.1002/jssc.201801112

A novel, low‐cost and effective in‐needle solid‐phase microextraction device was developed for the enrichment of trace polycyclic aromatic hydrocarbons in water samples. The in‐needle solid‐phase microextraction device could be easily assembled by inserting hydrofluoric acid‐etched wires, which were used as adsorbent, into a 22‐gauge needle tube within spring supporters. Compared with the commercial solid‐phase microextraction fiber, the developed device has higher efficiency for the extraction of polycyclic aromatic hydrocarbons with four to six rings from water samples using the optimized extraction conditions. With gas chromatography equipped with a flame ionization detector, the limits of detection for the polycyclic aromatic hydrocarbons with four to six rings ranged from 0.0020 to 0.0067 ng/mL. The relative standard deviations for one needle and needle‐to‐needle extractions were in the range of 5.2–9.9% (n = 5) and 3.4–12.3% (n = 5), respectively. The spiked recoveries of the polycyclic aromatic hydrocarbons in tap water samples ranged from 73.2 to 95.4%.

This in‐needle solid‐phase microextraction device could be a good field sampler because of the low sample loss over a long storage time.



Fine-grained sedimentary rocks are well developed in a salinized lacustrine basin in the Junggar Basin, China. Understanding the sedimentary characteristics and process of these fine-grained sediments is essential to find the exploration target for tight oil. In this study, the sedimentary characteristics and forming mechanism of fine-grained sediments in the Permian Lucaogou Formation within the Jimsar Sag were investigated based on core and thin section observation, SEM combined with XRD and geochemical data, and eleven lithofacies were identified, including (1) brecciated dolomitic mudstone, (2) intraclastic conglomerate, (3) mixed siliciclastic and intraclastic grainstone, (4) dolomitic siltstone, (5) Carbonate packstone and grainstone, (6) dolomitic mudstone, (7) laminated algae-bearing tuffaceous mudstone, (8) massive tuffaceous mudstone, (9) turbidite dolomitic mudstone to siltstone, (10) pebbled sandstone, and (11) green mudstone and siltstone. The organic constituents in the fine-grained sedimentary rocks include sapropelic, exinite, vitrinite, inertinite and secondary macerals, which are dominated by unstructured algae and asphaltene. The fine-grained sedimentary rocks are characterized by high-frequency cycles composed of three successive facies associations: profundal, littoral–sublittoral and palustrine, which recorded distinct lacustrine expansion and contraction. Developed mud cracks, paleosols and vertical dissolution fractures in the fine-grained sedimentary rocks indicate that these facies recorded the depositional process in an ephemeral to perennial lake in an arid climate. Fluvio-deltaic and aeolian transport were main modes for transporting the siliciclastic component that ultimately accumulated in a subaqueous and subaerial environment. The dolomite in the littoral zone might develop with the evaporitic concentration of the lake water during the early diagenetic stage. The depositional processes in the profundal zone included suspension and turbidity currents. Multiphase volcanic activities affected the lithofacies and prompted the accumulation of organic matter. Understating the depositional process of the fine-grained sedimentary rocks in the Lucaogou Formation in the Jimsar Sag is helpful to understand the depositional environment in the salinized lacustrine basin in the Junggar Basin.

Yang, Z., Zhang, Z., 2019. Recent advances on production of 2, 3-butanediol using engineered microbes. Biotechnology Advances 37, 569-578.


As a significant platform chemical, 2, 3-butanediol (2, 3-BD) has found wide applications in industry. The success of microbial 2, 3-BD production was limited by the use of pathogenic microorganisms and low titer in engineered hosts. The utilization of cheaply available feedstock such as lignocellulose was another major challenge to achieve economic production of 2, 3-BD. To address those issues, engineering strategies including both genetic modifications and process optimization have been employed. In this review, we summarized the state-of-the-art progress in the biotechnological production of 2, 3-BD. Metabolic engineering and process engineering strategies were discussed.

Yin, S., Xie, R., Zhao, J., 2019. Analysis of adsorption kinetics and thermodynamics of methane in shale based on the volume filling theory of micropores. International Journal of Oil, Gas and Coal Technology 21, 26-38.

https://www.inderscience.com/info/inarticle.php?artid=99523

Volume filling of micropores is an adsorption behaviour of adsorbates at higher equilibrium pressures. In this paper, the meaning of the parameters defined in the volume filling theory of micropores is discussed, and the adsorption performance of methane in shale is analysed. Research indicates that it is most appropriate to use the characteristic index curve n = 1 to describe the adsorption behaviour of methane in shale. As adsorption capacity increases, the differential adsorption work (A) will decrease. As the temperature increases, the characteristic energy (E) tends to decrease gradually, and for the case of n = 1, the values of E for shale samples ranged from 4.14 to 5.63 kJmol−1. As the filling rate θ increases, the absolute values of the thermodynamic parameters (Q, ΔH and ΔS) decrease gradually. Under experimental P-T conditions, the values of the thermodynamic parameters change very regularly and do not have mutation characteristics. This indicates that the adsorption energy can be extrapolated under much wider supercritical conditions. We believe that the thermodynamic parameters actually represent the complementarity and comprehensive effects of the TOC and Ro parameters.



In a series of isothermal depressurizing tests to measure asphaltene onset pressure (AOP), several depressurizing operations are usually conducted to multiple AOPs using the same lot of fluid subsamples. After one depressurizing operation is finished, the pressure/temperature condition is reset to the initial condition. Then, the next depressurizing run is performed. Before the next run, the fluid sample must equilibrate again by dissolving precipitated asphaltenes from the previous step. According to our many experiences with isothermal depressurizing tests for measuring AOPs, we know that redissolving asphaltenes depends highly upon the characteristics of a fluid sample. Some fluids redissolve asphaltenes quickly, while other samples need a lot of time. This study focused on fluid-dependent asphaltene re-equilibrium during a series of isothermal depressurizing tests. To investigate asphaltene re-equilibrium, the authors re-examined past experimental data for two types of crude oils. In the experiment, continuous power of light transmittance (PLT) was monitored for all stages in the series of AOP measurements. Two series of isothermal depressurizing tests were separately performed to evaluate CO2-induced asphaltene risks for two fluid samples. Three or four total steps of depressurizing were conducted in order of CO2 addition ratios: 0, 20, 40, and 60 mol %. After a depressurizing process finished, pressure was increased above AOP to dissolve precipitated asphaltenes. PLT profiles in equilibrium steps between each depressurizing step were compared from a viewpoint of equilibrium time and/or PLT profile fluctuation. One of the fluids showed quick re-equilibrium of asphaltenes and smooth PLT profiles, whereas the other took much longer to achieve equilibrium and had fluctuating PLT profiles. This information suggested that easy-equilibrium-achievable fluids would be a preferred target for CO2 enhanced oil recovery because of its potential use of pressure control for mitigating asphaltenes. In the case of easy-equilibrium-achievable fluid, when a production problem is caused by asphaltene precipitation, repressurization by temporary shut-in and/or production rate control can be an effective mitigation.

Yoneda, M., Kisida, K., Gakuhari, T., Omori, T., Abe, Y., 2019. Interpretation of bulk nitrogen and carbon isotopes in archaeological foodcrusts on potsherds. Rapid Communications in Mass Spectrometry 33, 1097-1106.

https://doi.org/10.1002/rcm.8446

Rationale: Foodcrust, the charred deposit adhering to the surface of containers, is a possible source of information on the function of ancient vessels and the subsistence of prehistoric humans. While the carbon isotope ratios in those materials are useful in detecting the usage of C4 plants, the reliability of nitrogen isotopic signatures has not been fully investigated.

Methods: The validity of bulk nitrogen isotope ratios has previously been investigated in coastal or riverine environments, where multiple resources from terrestrial and aquatic ecosystems were available, but not in terrestrial settings which provide a simpler mixing of terrestrial animals and plants. Hence, we conducted an exhaustive study on charred deposits on potsherds at two inland archaeological sites belonging to prehistoric Jomon hunter‐gathers in central Japan, focusing on δ15N values and atomic N/C ratios determined using an isotope ratio mass spectrometer and an elemental analyzer, respectively.

Results: For both sites, the δ15N values showed significant correlations with the N/C ratios among samples from the inner surface, suggesting that these have recorded animal contribution. Furthermore, previous studies of Neolithic pottery from North Europe and Far East Russia bearing strong marine signatures had shown reasonably higher δ15N values and N/C ratios in comparison with our data from terrestrial settings. On the other hand, some charred materials probably originating from plant starch showed lower values with both parameters. Samples from the outer surface produced less meaningful isotopic and elemental ratios altered by a thermal effect and/or contamination from soot.

Conclusions: When the samples of foodcrusts were selected carefully from the inner surface, bulk nitrogen isotopes and N/C ratios reflect the composition of what was cooked or processed in containers. This will provide useful information for understanding the human adaptation from the Late Pleistocene to the Holocene in conjunction with residual lipid analyses.

Yu, J., Wang, P., Ni, F., Cizdziel, J., Wu, D., Zhao, Q., Zhou, Y., 2019. Characterization of microplastics in environment by thermal gravimetric analysis coupled with Fourier transform infrared spectroscopy. Marine Pollution Bulletin 145, 153-160.


As a global pollutant, microplastics have attracted attention from the public and researchers. However, the lack of standard and time-saving methods for analysis has become one of the bottlenecks in microplastics research. Here, we demonstrate TGA coupled to FTIR to identify and quantify certain microplastics in environment. Samples were pyrolyzed in TGA and the pyrolysis gases were analyzed by FTIR. Combining TGA and FTIR data adds discriminatory power as temperature profiles and absorption spectra differ among several common plastics. To quantify on a mass basis, we calibrated on characteristic IR peaks at temperatures of maximum weight loss for individual polymers. The method can distinguish PVC, PS and was validated by spiking samples with known quantities of microplastics. The result of field sample experiments showed that TGA-FTIR can be used to identify and quantify PVC and PS in bivalves, seawater and soil. And the method may be applicable to environmental samples.

Yu, W., Zhang, Y., Varavei, A., Sepehrnoori, K., Zhang, T., Wu, K., Miao, J., 2019. Compositional aimulation of CO2 huff ‘n’ puff in Eagle Ford tight oil reservoirs with CO2 molecular diffusion, nanopore confinement, and complex natural fractures. SPE Reservoir Evaluation & Engineering 22, 492-508.

https://doi.org/10.2118/190325-PA

Although numerous studies proved the potential of carbon dioxide (CO2) huff ’n’ puff, relatively few models exist to comprehensively and efficiently simulate CO2 huff ’n’ puff in a way that considers the effects of molecular diffusion, nanopore confinement, and complex fractures for CO2. The objective of this study was to introduce a numerical compositional model with an embedded-discrete-fracture-model (EDFM) method to simulate this process in an actual Eagle Ford tight oil well. Through nonneighboring connections (NNCs), the EDFM method can properly and efficiently handle any complex fracture geometries. We built a 3D reservoir model with six fluid pseudocomponents. We performed history-matching with measured flow rates and bottomhole pressure (BHP). Good agreements between field data, EDFM, and local grid refinement (LGR) were achieved. However, the EDFM method performed faster than the LGR method. After that, we evaluated the CO2-enhanced-oil-recovery (EOR) effectiveness for molecular diffusion and nanopore confinement effects. The traditional phase equilibrium calculation was modified to calculate the critical fluid properties with nanopore confinement. The simulation results showed that the CO2 EOR with larger diffusion coefficients performed better than the primary production. In addition, both effects were favorable for the CO2 huff ’n’ puff effectiveness. The relative increase of cumulative oil production after 20 years was approximately 12% for this well. Furthermore, when considering complex natural fractures, the relative increase of cumulative oil production was approximately 8%. This study provided critical insights into a better understanding of the impacts of CO2 molecular diffusion, nanopore confinement, and complex natural fractures on well performance during the CO2-EOR process in tight oil reservoirs.

Zak, M., 2019. A model of emerging intelligence in Universe. International Journal of Astrobiology 18, 251-258.

https://doi.org/10.1017/S1473550417000489

The paper proposes a scenario of origin and emerging of intelligent life in Universe based upon the mathematical discovery of a new class of dynamical systems described by ordinary differential equation (ODE) coupled with their Liouville equation. These systems called self-controlled since the role of actuators is played by the probability produced by the Liouville equation. Following the Madelung equation that belongs to this class, non-Newtonian and quantum-like properties such as randomness, entanglement and probability interference typical for quantum systems have been described. At the same time, these systems expose properties of livings: decomposition into motor and mental dynamics, the capability of self-identification and self-awareness, as well as self-supervision. But the most surprising discovery is the existence of a special sub-class, in which the dynamical systems can violate the second law of thermodynamics, and that makes them different from both Newtonian and quantum physics. This sub-class should be associated with intelligent livings due to capability to move from disorder to order without external help. Based upon the mathematical discovery described above, one can assume that there are good chances that similar dynamical systems representing intelligent livings exist in real physical world. This provides a reason for a ‘rehabilitation’ of the Maxwell demon and put it into physics of intelligent systems. Indeed, the Maxwell demon is implemented by the feedback from the Liouville equation to the original ODE, while this feedback is capable to rearrange the probability distribution against the second law of thermodynamics. In addition to that, the same feedback removes the entropy paradox by explaining

high order in our surrounding by ‘intelligent life support’. Two-steps transition: from the Newtonian physics to the linear model of life, and from the latter to the model of intelligent life are analysed. The first transition is triggered by the Hadamard instability of the Newtonian physics with respect to small random disturbances in linear terms of the Liouville feedback. The second transition is triggered by instability of linear model of life with respect to small random disturbances of non-linear terms of Liouville feedback. This transition could be implemented by such physical phenomena as shock waves or negative diffusion in probability space. Both transitions can be associated with catastrophe theory, in which sudden shifts in behaviour arises from small changes in parameters of the model. In view of the proposed model, possible competition between artificial and human intelligence are discussed.

Zakharyuk, A.G., Ryzhmanova, Y.V., Avtukh, A.N., Shcherbakova, V.A., 2019. Iron-reducing microbial communities of the Lake Baikal low-temperature bottom sediments. Microbiology 88, 156-163.

https://doi.org/10.1134/S0026261719020139

Psychroactive enrichment cultures reducing anthraquinone 2,6-disulfonate (AQDS) and soluble complexes of ferric iron at 5–20°C were isolated from the samples of Lake Baikal bottom sediments collected at the depths of 404 to 1396 m. Cultivation resulted in production of up to 6 mM Fe(II), which was over 50% of the initial Fe(III) concentration in the medium, and of 5.5 mM AH2QDS (~30% of the initial quinone concentration). The enrichment culture of iron-reducing bacteria St3 used Fe(III) citrate as the terminal electron acceptor, oxidizing formate from 6.5 to 2.0 g L–1 at 15°C. Phylogenetic analysis showed that the initial samples of the Lake Baikal bottom sediments and the enrichments obtained from these samples contained the taxa of classes Alpha- and Betaproteobacteria, which were closely related to bacteria capable of oxidizing aromatic compounds using inorganic electron acceptors, including ferric iron.

Zeng, A.-P., 2019. New bioproduction systems for chemicals and fuels: Needs and new development. Biotechnology Advances 37, 508-518.


Currently used bioproduction systems for chemicals and fuels are primarily based on sugar-containing substrates. They have inherent limitations regarding substrate sustainability and affordability, product spectrum and yield, and costs for up- and downstream processing. To overcome some of these major burdens new bioproduction strategies and systems are being developed, including biorefinery, electro-biotechnology (use of electricity for biosynthesis) and C1 bioeconomy using synthetic biological systems based on C1 carbon feedstocks such as CO, CO2, methane, methanol and formic acid. In this article, the promises, development trends and challenges of these new bioproduction systems and concepts are briefly summarized and discussed.

Zha, J., Zhuang, Q., 2019. Microbial dormancy and its impacts on Arctic terrestrial ecosystem carbon budget. Biogeosciences Discussions 2019, 1-44.


A large amount of soil carbon in the Arctic terrestrial ecosystems could be emitted as greenhouse gases in a warming future. However, lacking detailed microbial processes such as microbial dormancy in current biogeochemistry models might have biased the quantification of the regional carbon dynamics. Here the effect of microbial dormancy was incorporated into a biogeochemistry

model to improve the quantification for the last and this century. Compared with the previous model without considering the microbial dormancy, the new model estimated the regional soils stored 75.9 Pg more C in the terrestrial ecosystems during the last century, and will store 50.4 Pg and 125.2 Pg more C under the RCP 8.5 and RCP 2.6 scenarios, respectively, in this century. This study highlights the importance of the representation of microbial dormancy in earth system models to adequately quantify the carbon dynamics in the Arctic.

Zha, M., Wang, S., Ding, X., Feng, Q., Xue, H., Su, Y., 2019. Tight oil accumulation mechanisms of the Lucaogou Formation in the Jimsar Sag, NW China: Insights from pore network modeling and physical experiments. Journal of Asian Earth Sciences 178, 204-215.


Pore network modeling and physical experiments were employed to understand the migration and accumulation of tight oil in the Lucaogou Formation of the Jimsar Sag, Junggar Basin, China. The pore structure characteristics of tight rock samples were statistically analyzed, from which some representative network models were constructed. The estimated petrophysical properties of these networks, e.g., porosity, permeability, and pore/throat size distribution, agree well with those obtained from experiments, which justified the effectiveness of our models. The experiments and simulations of oil migration into tight rocks suggest that there are mainly two different types of accumulation patterns, i.e., rapid growth pattern and consistent growth pattern, which are characterized by S-shaped and modified S-shaped correlations of oil saturation and pressure gradient, respectively. Oil accumulation mainly occurs in the middle stage; however, the increment of oil saturation of consistent growth pattern is much slower than that of rapid growth pattern. The water-oil relative permeability curves, which describe the fluid transport capabilities during oil migration, were also computed from simulations. The effects of coordination number, aspect ratio, as well as clay volume were analyzed. Results show that a core sample having better connectivity and more homogeneous pores and throats facilitates the oil migration; however, a higher clay volume impedes oil accumulation and decreases the final oil saturation. This work not only provides a better understanding of tight oil accumulation mechanisms, but also supplies an alternative avenue to study multiphase flow in tight rocks.

Zhai, J., Wang, X., Qin, B., Cui, L., Zhang, S., Ding, Z., 2019. Clumped isotopes in land snail shells over China: Towards establishing a biogenic carbonate paleothermometer. Geochimica et Cosmochimica Acta 257, 68-79.


Land snail fossils are abundantly distributed in geological deposits and their isotopic compositions provide a means to determine paleoclimatic changes. With the development of the clumped isotopes (Δ47) geothermometer, many efforts have been made in recent years to study clumped isotopes in land snail shell carbonate. Although there have been several recent attempts, there is, as yet, no empirical calibration function to convert land snail Δ47 to environmental temperature. Here, we systematically analyzed clumped isotopes (Δ47) of two common land snail species (Bradybaena and Cathaica) from China. Results showed that temperatures calculated using the Δ47 (T47) of both species did not correlate with the mean annual temperatures (MAT) at the study sites. However, the T47-MAT offset is negatively correlated to MAT, suggesting that land snails tend to add shell during the warmer months at colder sites or modulate their body temperature differently in colder regions. Meanwhile, clumped temperatures of Cathaica are 3.4 ± 1.5 °C higher than those of Bradybaena at 18 sites, indicating that a species-specific transfer function is needed to reconstruct paleotemperature using

land snail clumped isotopes. After determining the proper duration of the growing season for land snails at different locations, we developed a Δ47-growth season temperature (GST) transfer function for the two species. The calibration function for Bradybaena land snails is expressed by a linear regression between 1/T2 and absolute Δ47 (R2 = 0.94): Δ47 = (0.0513 ± 0.0036) × 106/T2 + (0.0930 ± 0.0413), where Δ47 is expressed in ‰ and T in K. The calibration function for Cathaica is as follows (R2 = 0.80): Δ47 = (0.055 ± 0.011) × 106/T2 + (0.035 ± 0.129). The function for Cathaica was successfully applied to reconstruct mean summer (June-July-August) temperatures during the Last Glacial Maximum and modern times on the central Chinese Loess Plateau, based on Δ47 data of Cathaica sp. provided by Eagle et al (2013a). This testifies to the validity of the aforementioned constructed transfer function. In addition, the calculated δ18O of body water (δ18OBW) for Bradybaena showed a robust correlation with the δ18O of rainfall (δ18Op), particularly in northern China, which points to the potential to trace hydrological changes in the region. In contrast, Cathaica δ18OBW did not show a straightforward relation to δ18Op. This inter-species complexity warrants further study.

Zhan, Y., Yang, M., Zhang, S., Zhao, D., Duan, J., Wang, W., Yan, L., 2019. Iron and sulfur oxidation pathways of Acidithiobacillus ferrooxidans. World Journal of Microbiology and Biotechnology Article 35, 60.

https://doi.org/10.1007/s11274-019-2632-y

Acidithiobacillus ferrooxidans is a gram-negative, autotrophic and rod-shaped bacterium. It can gain energy through the oxidation of Fe(II) and reduced inorganic sulfur compounds for bacterial growth when oxygen is sufficient. It can be used for bio-leaching and bio-oxidation and contributes to the geobiochemical circulation of metal elements and nutrients in acid mine drainage environments. The iron and sulfur oxidation pathways of A. ferrooxidans play key roles in bacterial growth and survival under extreme circumstances. Here, the electrons transported through the thermodynamically favourable pathway for the reduction to H2O (downhill pathway) and against the redox potential gradient reduce to NAD(P)(H) (uphill pathway) during the oxidation of Fe(II) were reviewed, mainly including the electron transport carrier, relevant operon and regulation of its expression. Similar to the electron transfer pathway, the sulfur oxidation pathway of A. ferrooxidans, related genes and operons, sulfur oxidation mechanism and sulfur oxidase system are systematically discussed.

Zhang, B., Yao, S., Wignall, P.B., Hu, W., Liu, B., Ren, Y., 2019. New timing and geochemical constraints on the Capitanian (Middle Permian) extinction and environmental changes in deep-water settings: evidence from the Lower Yangtze region of South China. Journal of the Geological Society 176, 588-608.


The Capitanian (Guadalupian) witnessed one of the major crises of the Phanerozoic and, like many other extinctions, it coincided with the eruption of a large igneous province, in this case the Emeishan Traps of SW China. However, the timing and causal relationships of this event are in dispute. This study concentrates on the deep-water chert–mudstone strata of the Gufeng Formation and its transition to the Yinping Formation at Chaohu. Zircons from tuffs in the uppermost Gufeng Formation yield a U–Pb age of 261.6 ± 1.6 Ma, and comparison with sections around Emeishan suggests that the tuffs appeared in the Jinogondolella altudaensis conodont zone and persisted to the Jinogondolella xuanhanensis zone. This coincides with the Emeishan eruptions, and suggests that the tuffs probably derived from this province. Mineralogical and geochemical characteristics also show the tuffs are of acid volcanogenic origin and have a geochemical fingerprint of the Emeishan large igneous province. Our dating shows that a crisis amongst radiolarian and a subsequent productivity

decline occurred during the middle Capitanian, prior to the Guadalupian–Lopingian boundary. The Emeishan eruptions began immediately before this, indicating a likely causal relationship between these events. Major regression and marine anoxia/euxinia are two other important extinction-relevant environmental changes that occurred during this critical interval.

Zhang, G., Qu, H., Chen, G., Zhao, C., Zhang, F., Yang, H., Zhao, Z., Ma, M., 2019. Giant discoveries of oil and gas fields in global deepwaters in the past 40 years and the prospect of exploration. Journal of Natural Gas Geoscience 4, 1-28.


Deepwater exploration has been developed for more than 40 years since 1975; generally, its exploration history can be divided into the beginning stage (1975–1984), the early stage (1985–1995) and the rapid development stage (1996-now). Currently, deepwater areas have become the hotspot of global oil and gas exploration, and they are also one of the most important fields of oil and gas increase in reserves and production all over the world. In 40 years, global deepwater oil and gas discoveries are mainly distributed along five deepwater basin groups which are characterized by “three vertical and two horizontal” groups: (1) In deepwater basins of the Atlantic Ocean, giant discoveries of oil are mainly concentrated in Brazil, West Africa and the Gulf of Mexico, and significant discoveries of natural gas are mainly on the west coast of Norway in the northern part of the Atlantic Ocean; (2) In deepwater basins of the East African continental margin, a group of giant gas fields has been found in the Rovuma Basin and Tanzania Basin; (3) In deepwater basins of the West Pacific Ocean, giant discoveries of oil and gas are mainly concentrated in the South China Sea and Southeast Asian waters; (4) The deepwater basins of the Neo-Tethys Region are rich in gas, and the most important gas discoveries are mainly distributed in the northwest shelf of Australia and the eastern Mediterranean; and (5) In deepwater basins around the Arctic Pole, major discoveries of oil and gas have been only found in deepwater areas of the Barents sea. Global deepwater oil resources are mainly concentrated in the middle and south sections of the Atlantic Ocean. Deepwater gas resources are relatively widely spread and mainly distributed in the northern part of Atlantic Ocean deepwater basins, the deepwater basins of East Africa, the deepwater basins of the Neo-Tethys region and the deepwater basins around the Arctic Pole. There will be six domains for future oil-gas exploration of global deepwater basins which are characterized by “two old and four new” domains; specifically, “two old” domains referring to the Atlantic offshore deepwater basins and offshore deepwater basins of the Neo-Tethys structural domain, where the exploration degree is relatively high, and the potential is still great. While the “four new” domains stand for pre-salt and ultra deepwater basin formations, offshore deepwater basins surrounding the North Pole area and West Pacific offshore deepwater basins and the new fields will be the main fields of deepwater oil and gas exploration in the future.



The Permian Fengcheng Formation in the western slope of the Mahu Sag, which is located in the Junggar Basin, NW China, has long been considered to be a high-quality source rock in this area. The lacustrine dolomitic rocks within the Fengcheng Formation has recently been reported to have a good tight oil potential as a special type of tight oil reservoir. However, the characteristics of the tight reservoir and tight oil accumulation, which are key factors for commercial development, are not well

documented. We conducted a comprehensive reservoir characterization using petrological (core, thin section, scanning electron microscope, and nanoscale computed tomography) and geophysical (seismic and well logging) data. The Fengcheng Formation contains extensive dolomitic rocks deposited around the evaporite under a saline lacustrine environment accompanied by volcanic activities. The western slope of the Mahu Sag can be divided into two zones: the Wufeng Fault Zone and Fengnan Slope Zone. Dolomitic rock reservoirs and tight oil accumulation exist in both zones. Salt minerals, feldspar, calcite, and dolomite in the dolomitic rocks are susceptible to dissolution, and secondary intergranular or intragranular dissolution pores are the major reservoir spaces. Abundant nanoscale pores exist in the dolomitic rocks, but microscale pores, which dominate in volume, play a more important role. Brittle dolomitic rocks commonly develop fractures, but the Wufeng Fault Zone develops far more fault-related fractures than the Fengnan Slope Zone. The oil properties of the Wufeng Fault Zone and the Fengnan Slope Zone are also different. We propose that these two zones are two different types of tight oil accumulation plays: a fracture controlled accumulation play and a pore controlled accumulation play.

Zhang, J., Cao, J., Wang, Y., Hu, G., Zhou, N., Shi, T., 2019. Origin of giant vein-type bitumen deposits in the northwestern Junggar Basin, NW China: Implications for fault-controlled hydrocarbon accumulation. Journal of Asian Earth Sciences 179, 287-299.


Giant vein-type bitumen deposits in the Wuerhe region within the northwestern Junggar Basin of NW China are representative examples of similar bitumen deposits that are found in a number of other locations in both China and elsewhere. These deposits can provide information on regional tectonics as well as insights into hydrocarbon and bitumen exploration, but the origin of the deposits remains unclear. This study focuses on determining the origin of the Wuerhe bitumen deposit using field, petrological, and geochemical data. Results show that the bitumen veins are generally hosted by shallow high-angle fault systems located within the nose of the Wuerhe fault-fold. The bitumen is of low maturity and has an organic origin, having formed by secondary alteration (most likely biodegradation) of crude oil sourced from the lower Permian Fengcheng Formation (P1f). The bitumen contains high concentrations of β-carotane and gammacerane, low concentrations of Ts and diasteranes, and comprises (in ascending order of concentration) C20–C21–C23 tricyclic terpanes and C27–C28–C29 regular steranes. The bitumen was most likely formed during the Early Cretaceous under the control of faults. A fault-controlled model is presented for hydrocarbon migration and accumulation and the subsequent formation of this bitumen within the northwestern Junggar Basin. This model suggests that future hydrocarbon exploration should focus on the cores of fault-fold noses and areas of minor-fold nose near deep-seated fault zones, especially where these areas correspond to potential moderate- to shallow-depth Jurassic–Cretaceous reservoirs. The new model should be able to guide exploration in other basins with similar tectonic settings of this study, i.e., superimposed thrusting, compression, and transtension.

Zhang, J., Kattner, G., Koch, B.P., 2019. Interactions of trace elements and organic ligands in seawater and implications for quantifying biogeochemical dynamics: A review. Earth-Science Reviews 192, 631-649.


Interactions between dissolved trace elements and organic ligands in seawater play an important role in ocean biogeochemistry, ranging from regulating primary production in surface waters to element cycling on basin-wide scale, with strong feedbacks to climate variability. In this study, we review

different aspects in the field of marine trace elements and their organic ligands: recent instrumental innovation, factors that affect the fate of trace element complexes at the molecular level, spatial distribution of organic matter – trace element complexes in the ocean, modeling approaches as well as prospect in the scenarios of climate variability. We also assess the critical issues of parameterization in the numerical simulation that incorporate the trace elements – organic ligands interactions. Given the predicted climate changes, we examine the potential of exchange between inorganic and organic complexes for trace elements in different oceanic provinces.

Zhang, J., Tang, Y., Chen, D., 2019. Prediction of methane adsorption content in continental coal-bearing shale reservoir using SLD model. Petroleum Science and Technology 37, 1839-1845.

https://doi.org/10.1080/10916466.2019.1610773

Shale gas, as an important unconventional resource, has drawn global attention. It is mainly composed of adsorption gas and free gas. Adsorption gas content could play an important guiding role on both the selection of favorable perspective area and the exploration and exploitation of shale gas resources. In order to accurately measure adsorption gas content, a new approach was established to predict the adsorption isotherm of methane on shale. Based on the simplified local-density (SLD) method, both the adsorption isotherms of illite, illite/smectite mixed-layer, cholorite and type III kerogen and the total shale rock could be well fitted. The fitting results show good coincidences with the true experimental test data, which proves the method is reasonable and dependable and the prediction results are effective and credible. In addition, the good simulation results show that the SLD parameters can reflect the pore structure characteristics and corresponding adsorption characteristics of the shale samples, which can be used for the quantitative characterization of shale pore system.

Zhang, L., Zhang, Y., Gamal El-Din, M., 2019. Integrated mild ozonation with biofiltration can effectively enhance the removal of naphthenic acids from hydrocarbon-contaminated water. Science of The Total Environment 678, 197-206.


An innovative biofiltration-ozonation-biofiltration process was established and applied for the treatment of oil sands process water (OSPW). With an equivalent hydraulic retention time (HRT) of 8 h, the biofiltration pretreatment removed 24.4% of classical naphthenic acids (NAs) and 3.3% of oxidized NAs from raw OSPW with removal rate of 0.4 mg/L/h and 0.1 mg/L. Oxidized NAs showed higher resistance to the biofiltration process than classical NAs. The mild ozonation process (with utilized ozone dose of 30 mg/L) removed 84.8% of classical NAs and 11.5% of oxidized NAs from the biofiltrated OSPW with a degradation efficiency of 0.3 mg classical NAs/mg O3 and 0.1 mg oxidized NAs/mg O3. However, by using the same utilized ozone dose, the degradation of classical NAs and oxidized NAs from raw OSPW was 32.1% and 3.9% with ozonation efficiency of 0.1 mg classical NAs/mg O3 and 0.0 mg oxidized NAs/mg O3, respectively. Compared with the biofiltration pretreatment, the post biofiltration process (with HRT of 8 h) showed higher degradation effect on oxidized NAs with removal ratio of 22.9% and removal rate of 0.4 mg/L/h, but showed lower degradation effect on classical NAs with removal ratio of 6.7% and removal rate of 0.0 mg/L/h. After biofiltration-ozonation-biofiltration treatment, the microbial community structure in the biofilter was investigated by next generation sequencing. Proteobacteria and Rhodococcus were dominant bacterial phyla and genus in the biofilter, the abundance of which were 47.21% and 9.50% which were different from those in raw OSPW (62.88% and 0.72%). The change of microbial community structure could be resulted from the interaction between microbial community and the circulating

OSPW. The ozonation integrated biodegradation process removed 89.3% and 34.0% of classical and oxidized NAs from OSPW which shows high potential to be applied by the oil and gas industry.

Zhang, R., Jin, Z., Liu, Q., Li, P., Huang, Z., Shi, J., Ge, Y., Du, K., 2019. Astronomical constraints on deposition of the Middle Triassic Chang 7 lacustrine shales in the Ordos Basin, Central China. Palaeogeography, Palaeoclimatology, Palaeoecology 528, 87-98.


The Middle Triassic was a key period that witnessed the evolution of Earth system processes and the commencement of a terrestrial lake in the Ordos Basin, Central China. A high-precision stratigraphic framework is the key to understanding the nature and pattern of critical geological events. Detailed time series analyses of magnetic susceptibility (MS) data were performed on the deep lacustrine shale-dominated Chang 7 Member of the Yanchang Formation from the Y1011 well core. The results reveal well documented cyclic variations with wavelengths of 5.37 m, 1.39–1.78 m, 0.48 m, and 0.24–0.30 m, which are driven by long-eccentricity, short-eccentricity, obliquity, and precession in the Middle Triassic. The stable 405-kyr tuned floating astrochronological time scale (FATS) reveals that the depositional duration of the Chang 7 Member is approximately 5 Myr, and the sedimentation rates range from 0.90 cm/kyr to 1.69 cm/kyr. In particular, the lower part of the Chang 7 Member is characterized by an organic-rich, black shale, called “Zhangjiatan Shale”, whose depositional duration can be estimated at about 1.7 Myr. Along with the published biostratigraphic divisions and U–Pb age constraints, our FATS further confirms that the Chang 7 Member mainly developed in the Ladinian Stage, and that the upper part of the Chang 7 spanned the Middle/Late Triassic boundary. The duration of the Chang 7 deposition suggests a temporal and genetic linkage between the responses of the Chang 7 shales in the Ordos Basin and the Indosinian Orogeny in the Qinling orogenic belt. The Ladinian Stage of the Middle Triassic probably witnessed a dramatic shift in the evolution of the regional geodynamic system.



Biooxidation of reduced inorganic sulfur compounds (RISCs) by thermoacidophiles is of particular interest for the biomining industry and for environmental issues, e.g. formation of acid mine drainage (AMD). Up to now, interfacial interactions of acidophiles with elemental sulfur as well as the mechanism of sulfur oxidation by acidophiles, especially thermoacidophiles, are not yet fully clear. This work focused on how a crenarchaeal isolate Acidianus sp. DSM 29099 interacts with elemental sulfur. Analysis by Confocal laser scanning microscopy (CLSM) and Atomic force microscopy (AFM) in combination with Epifluorescence microscopy (EFM) shows that biofilms on elemental sulfur are characterized by single colonies and a monolayer in first stage and later on 3-D structures with a diameter of up to 100 micrometers. The analysis of extracellular polymeric substrances (EPS) by non-destructive lectin approach (fluorescence lectin-barcoding and analysis) using several fluorochromes shows that intial attachment was featured by footprints rich in biofilm cells were embeded in a EPS matrix consists various of glycoconjugates. Wet chemistry data indicate that carbohydrates, proteins, lipids and uronic acids are the main components. Attenuated reflectance (ATR)-Fourier transformation infrared spectroscopy (FTIR) and high-performance anion exchange chromatography with pulsed amperometric detection (HPAE-PAD) indicate glucose and mannose as the main monosaccharides in EPS polysaccharides. EPS composition as well as sugar types in EPS

varies according to substrate (sulfur or tetrathionate) and lifestyle (biofilms and planktonic cells). This study provides information of the building blocks/make up as well as dynamics of the thermoacidophilic archaeon biofilms in extremely acidic environments.

Zhang, S., Zhu, J., Zhan, H., Meng, Z., Chen, R., Liang, H., Zhao, K., Yue, W., 2019. Laser-induced voltage application for identification of crude oils. Energy & Fuels 33, 3855-3858.


In this work, laser-induced voltage (LIV) was used to assess three various crude oils using a 248 nm ultraviolet laser. Under the same bias voltage, the peak of LIV (Vp) increased with the increase in the overall laser energy irradiating the surface of the sample. The increase in the bias voltage contributed to the improvement of Vp at the same laser energy. On the basis of our results, samples with more oxygen content generated more charge, which led to the higher Vp. Our research indicates that LIV is a suitable approach for the identification of various crude oils.

Zhang, T., Chen, X., Shen, H., Da, Z., 2019. Upgrading of Tsingtao vacuum residuum in supercritical water (I): A preliminary phase structure study by molecular dynamics simulations. Energy & Fuels 33, 3908-3915.


The dissolution of heavy oil represented by Tsingtao vacuum residuum (VR) in supercritical water (SCH2O) was investigated with molecular dynamics simulations. The dissolution of oil fractions in SCH2O is promoted by the electrostatic attraction with SCH2O but suppressed by the interaction between oil fractions themselves. According to the simulation started with the oil-in-water emulsion structure, light fractions of saturates and aromatics dissolve rapidly in SCH2O. The dissolution of heavy fractions of resins and asphaltenes, which contain a large number of benzene, naphthenic, and heterocyclic rings, in SCH2O, however, is suppressed, and can be adjusted partly by varying the thermodynamic state of water. By the differences in the solubility of oil fractions in SCH2O and the operation conditions applied, the mixture of Tsingtao VR and SCH2O exists in the two-phase, oil-in-water emulsion or the pseudo single-phase structure. In the emulsion structure, the dissolution of light fractions into the continuous SCH2O surroundings is accelerated, leaving heavy fractions concentrated in the oil droplets.

Zhang, T., Wang, Z., Wang, Y., Wei, Z., Li, X., Hou, X., Sun, Z., Wang, G., Qian, Y., 2019. The characteristics of free/bound biomarkers released from source rock shown by stepwise Py-GC-MS and thermogravimetric analysis (TGA/DTG). Journal of Petroleum Science and Engineering 179, 526-538.


Three organic-rich shales with different types of kerogen (Type I and II1) were conducted to pyrolysis by step, which was performed in three temperature stages based on thermogravimetric analysis (TGA/DTG), to investigate the characteristics of both free and bound biomarkers. Additionally, the free biomarkers of the source rocks were also compared by GC-MS with the flash pyrolyzate in different steps. The pyrolyzate of the first stage (100–250 °C) includes n-alkanes, terpanes and steranes were same as the extractable lipids in distribution, suggesting that the free biomarkers can be obtained at the first stage. The pyrolyzate released at the second stage was dominated by n-alkane/n-alkene doublets (C4-C29) with a unimodal distribution. A full suite of long

chain n-alkanes made its first appearance in the third stage, but the parameters of terpanes and steranes appeared to more immature than their corresponding free counterparts, indicating the bound biomarkers released in the third stage which preserved the information of kerogen at an early and immature stage. The study of light hydrocarbons (C4-C13) in three flash pyrolyzate confirmed that the biomarkers in the first stage had a free status, while in the second and third stage, the light hydrocarbons were greatly affected by maturity. The results showed that stepwise pyrolysis is capable of releasing both free and bound biomarkers that can be used in the geochemical characterisation of the source rocks. Importantly, the biomarker parameters at 100–250 °C of source rocks flash pyrolyzate can be used as extracts counterparts and avoided tedious pretreatments.



Elucidation of the linkages between the bacterial community composition and chromophoric dissolved organic matter (CDOM) in lake ecosystems is critical for the understanding of the inland water carbon cycling. Despite substantial research into the relationship between the bacteria community and the bulk DOM pool, knowledge of the specific relationship between the optical dynamics of DOM and the bacterioplankton community in lake ecosystems is still poor. We investigated the linkages between the optical dynamics of DOM and bacteria composition in shallow eutrophic Lake Taihu, China. Redundancy Analysis (RDA) indicated that besides water temperature and phytoplankton biomass, also CDOM was an important factor determining the composition of the bacterial community. Generalized Additive Models (GAM) showed that terrestrial humic-like C1 and tyrosine-like C4 were the key factors explaining the abundance of the main bacterial clades. C1 was closely correlated with Verrucomicrobia, Actinobacteria, Alphaproteobacteria, Betaproteobacteria and Planctomycetes, and C4 was closely related to the latter two and to Bacteroidetes. At family level, the dominant families – Pelagibacteraceae (Alphaproteobacteria) and Gemmataceae (Planctomycetes) – were related to both allochthonous and autochthonous CDOM fluorophores but responded differently to the various CDOM components. Tryptophan-like C2 was significantly and positively correlated with Gemmataceae and Ellin6075 (Acidobacteria). Additionally, we found that the biomasses of Cyanophyta, terrestrial humic-like C1, tryptophan-like C4 and C5 were significantly related to the richness of heterotrophic bacterioplankton. Our results provide new insight into the relationship between bacteria and DOM optical dynamics although the mechanisms leading to these relationships need further experimental investigations.


https://doi.org/10.1080/01490451.2019.1578441

Nitrite-dependent anaerobic methane oxidation (n-damo) process, mediated by Candidatus Methylomirabilis oxyfera of the candidate phylum NC10, was discovered recently which plays an important role in coupling the global nitrogen and carbon cycles. However, the distribution and diversity of this new anaerobic methane-oxidizing microorganism have not been investigated in desert lakes yet. The present study successfully retrieved n-damo bacterial 16S rRNA and pmoA gene sequences using PCR technique from lakes in Badain Jaran Desert of China. Phylogenetic analyses showed that n-damo bacteria widely occurred in brine and freshwater lakes on the desert with high

diversity, including both sediment and water samples. The results of quantitative PCR indicated that the abundance of the 16S rRNA gene in lake sediments varied from 1.12 ± 0.68 × 105 to 1.64 ± 0.70 × 105 copies g−1 (dry weight), while that in water samples per milliliter was generally one order of magnitude lower than sediments. Correlation analyses suggested that n-damo bacterial abundance and diversity strongly depended on salinity. In lake sediments, the distribution, abundance, and diversity of n-damo bacteria were significantly associated with depth due to the concentration gradient of the NOx

- and ammonium. This study provided new insights into both the n-damo community patterns and its interaction with ambient environmental factors in the desert lake ecosystem.



Systemic studies are lacking to derive an understanding from the limited number of individually imaged diverse structures from noncontact atomic force microscopy and relate them to the chemistry of a macroscopic ensemble of a heterogeneous petroleum mixture. This initial study intends to fill this gap by studying polycyclic aromatic hydrocarbons (PAHs) and understanding their aromaticity and bonding orders. Both alternant and nonalternant PAHs are present in petroleum molecules, and the significance of nonalternant hydrocarbons in disrupting electron distribution of aromatic hydrocarbons was revealed by quantifying local aromaticity using nucleus-independent chemical shift, complemented by the qualitative prediction with Clar’s sextet theory. We found that local aromaticity is maximized, resulting in a new understanding of large aromatic structures in petroleum. In addition, bond order analysis on PAHs from atomic force microscopy imaging revealed that partial double bond character is common in petroleum molecules and could reach a significant degree in certain sites in a structure, with important implications in a wide range of reactivities and properties. Overall, this preliminary study provides means and methodology to connect finite structures from single-molecule imaging with infinite diverse molecules in petroleum.

Zhang, Y., Pufahl, P.K., Du, Y., Chen, G., Liu, J., Chen, Q., Wang, Z., Yu, W., 2019. Economic phosphorite from the Ediacaran Doushantuo Formation, South China, and the Neoproterozoic-Cambrian Phosphogenic Event. Sedimentary Geology 388, 1-19.


Phosphorite of the Ediacaran Doushantuo Formation accumulated in the central Guizhou province during the Neoproterozoic-Cambrian Phosphogenic Event, producing the first true phosphorite giant in Earth history. Deposition is interpreted to have occurred on a wave-dominated epeiric platform along the northern margin of the Qianzhong Uplift. Lithofacies stacking patterns and two paleokarst surfaces record phosphogenesis through at least two sea-level cycles. As in younger Phanerozoic epeiric sea phosphorites, the delivery of upwelled phosphorus is interpreted to have stimulated phosphogenesis in a range of shallow-water environments.

Ten phosphatic and associated lithofacies are recognized in the Doushantuo Formation. Wavy and horizontal laminated pristine facies were the locus of phosphogenesis and reflect the authigenic precipitation of francolite in accumulating fine sediment. Granular, cross-stratified phosphorite is interpreted to have been produced through storm-wave winnowing of pristine facies and the subsequent transport, redeposition, and concentration of phosphatic peloids into economic beds. Beds with the highest concentration of phosphorus formed in shallow, wave-agitated environments around

paleo-topographic highs. Paragenetic analysis suggests that secondary meteoric processes further enriched the phosphorus content (>35 wt%) of these granular beds during sea-level lowstands.

Such aerially extensive, upwelling-related phosphorite contrasts Paleoproterozoic and Neoproterozoic phosphatic deposits. Throughout much the Proterozoic francolite precipitation was restricted to shallow-water, photosynthetic oxygen oases where redox sensitive phosphogenic processes were focused in the sediment. The Doushantuo Formation is interpreted to record the oxygenation of the water column and concomitant expansion of phosphogenic environments during the Neoproterozoic Oxygenation Event. This progressive ventilation of the deep ocean forever changed the biogeochemical cycling of phosphorus in the marine realm and set the stage for the deposition of phosphorite giants that punctuate the Phanerozoic stratigraphic record.



China has a considerable lignite deposit in the Xinjiang province, but surface and underground coal seam fires pose a threat to the resources, environment, economy, and health. As the chemical and physical structure impacts coal fire propensity and behavior, two raw Xinjiang lignites were examined from the Shaerhu (SEH) and Piliqing (PLQ) Collieries. The SEH lignite is more prone to spontaneous combustion (from regional observations). These coals were of the same geological age and were both inertinite-rich 69.8 and 95.6% for SEH and PLQ, respectively (by the point counting approach). The more spontaneous combustion prone lignite had a significantly higher micropore contribution and surface area (92.4% and 195.6 m2/g), while both coals had similar micro- and mesopore size distribution ranges. Despite being classified as lignite by the mean vitrinite random reflectance (Rr, 0.30 and 0.26%) the inertinite contribution displaces some of the structural properties to be similar to the vitrinite-rich, high-volatile bituminous rank. The lignite coals had similar carbon content (74.6 and 78.4 wt % for SEH and PLQ) and vitrinite reflectance but differed in ash, volatile matter, total moisture, and fixed carbon yields. The crystallite parameters [from X-ray diffraction (XRD)], the interlayer spacing, crystallite height, crystallite diameter, and the numbers of aromatic layer indicated the more inertinite-rich coal (PLQ) was slightly less ordered. Both coals were highly aromatic for lignites (fa’ values of 0.72 and 0.71 for SEH and PLQ), as the inertinite-rich components are more aromatic and polycondensed than huminite-rich (a low rank counterpart of vitrinite) coals of similar reflectance values. Image analysis of high-resolution transmission electron microscopy lattice fringes determined the aromatic fringe length distributions, with contributions between 0.25 and 0.50 nm accounting for 37.1% for PLQ, while SEH had a lower contribution of 28.0% but also a greater contribution of longer fringes (larger polycyclic aromatic hydrocarbon cluster sizes). Image analysis of the lattice fringe orientation and XRD analysis also indicated that the SEH lignite was more ordered. These two coals are potential coals for further exploration of spontaneous combustion behavior for inertinite-rich coals.

Zhang, Y., Zhao, W., Wang, D., Zhang, H., Chai, G., Zhang, Q., Lu, B., Sun, S., Zhang, J., 2019. Direct analysis of carbonyl compounds by mass spectrometry with double-region atmospheric pressure chemical ionization. Analytical Chemistry 91, 5715-5721.


Direct analysis of highly reactive volatile species such as the aliphatic aldehydes as vital biomarkers remains a great challenge due to difficulties in the sample pretreatment. To address such a challenge, we herein report the development of a novel double-region atmospheric pressure chemical ionization mass spectrometry (DRAPCI-MS) method. The DRAPCI source implements a separated structural design that uses a focus electrode to divide the discharge and ionization region to reduce sample fragmentation in the ionization process. Counterflow introduction (CFI) configuration was adopted in the DRAPCI source to reduce background noise, while ion transmission efficiency was optimized through simulating the voltage of the focus electrode and the ion trajectory of the ion source. The limits of detection (LODs) of four carbonyl compounds cyclohexanone, hexanal, heptanal, and octanal by DRAPCI-MS were between 0.1 and 3 μg·m–3, approximately two to eight times lower than those by atmospheric pressure chemical ionization mass spectrometry. Additionally, the DRAPCI-MS method carried out effective in situ analyses of the volatile components in expired milk and the exhaled breath of smokers, demonstrating the DRAPCI-MS as a practical tool to analyze complex mixtures. The DRAPCI-MS method provides a rapid, sensitive, and high-throughput technique in the real-time analysis of gaseous small-molecule compounds.

Zhang, Z., Zhang, Y., Zhu, G., Han, J., Chi, L., 2019. Variations of diamondoids distributions in petroleum fluids during migration induced phase fractionation: A case study from the Tazhong area, NW China. Journal of Petroleum Science and Engineering 179, 1012-1022.


Diamondoids, resistant to thermal and biological destruction, are useful in identifying the genesis and alteration history of petroleum fluids, especially for condensates in which conventional biomarkers are of trace amounts. Tremendous condensate resources have been discovered in the Ordovician carbonates from the central Tarim Basin, however, the complex genesis and distribution of the condensates have brought challenges in effective exploration and fluid prediction. In this study, the GC × GC-TOFMS analyses were applied on several condensate oil samples. Results showed great variance in the distribution and absolute concentration of diamondoids. Accompany the integrated geochemical and geologic analyses, the studied condensates are ‘daughter’ condensates generated from the similar ‘parent’ condensates that have undergone severe phase fractionation induced by migration. Phase fractionation led to the constant loss of vapor fractions and enriched heavy fractions in the residual condensates during the migration of petroleum fluids towards structural highs. Accordingly, diamondoids were preferentially enriched in shallower condensates and depleted in residual condensates, such variations of diamondoids distributions are attributed to phase fractionation because diamondoids with different molecular sizes differ in the solubilities in vapor phase. This will bring insight into the genesis of secondary condensates and the evaluation of the fractionation extent of petroleum fluids, with which effective petroleum exploration and prediction can be obtained.

Zhao, K., Du, X., Lu, Y., Xiong, S., Wang, Y., 2019. Are light-dark coupled laminae in lacustrine shale seasonally controlled? A case study using astronomical tuning from 42.2 to 45.4 Ma in the Dongying Depression, Bohai Bay Basin, eastern China. Palaeogeography, Palaeoclimatology, Palaeoecology 528, 35-49.


As a typical sedimentary structure in fine-grained rocks, laminae are widely distributed in shales and mudstones in sedimentary basins. The Shahejie Formation (42.2–45.4 Ma) formed during the Eocene of the Paleogene in the Dongying Depression of China is recognized as a typical area to study

lacustrine shale. According to the composition of different lamina, four types of couplets are identified, including carbonate-clay couplets, carbonate-organic couplets, clay-organic couplets and carbonate-clay-organic triplets. All couplets are composed of light and dark layers. A combination of core images, microscopic observations, mineral compositions, geochemical data, carbon and oxygen isotopes, and strontium isotopes verifies that the laminae are primarily developed in a saline and anoxic, or even euxinic environment, with a high organic matter (OM) flux. Through astronomical cycle analysis of the natural gamma ray (GR) curve from sample site well NY1, the data suggest that the lacustrine shale laminae are formed annually with an average duration of 1.34 yr. The formation of laminae is affected by the season, which is closely related to the seasonal growth and death of algae. During the period of algae growth, a large number of light-colored carbonate laminae are deposited, whereas when the algae dies, organic matter accumulates at the bottom of lakes and forms dark organic-rich laminae. The interbedded and lenticular laminae, which are subdivided by layering characteristics, are primarily affected by diagenesis in postdepositional processes. Study of the laminae is helpful in understanding the formation process of lacustrine shale, and it provides invaluable sources of information for paleoclimate reconstruction.


https://doi.org/10.1007/s11430-018-9312-4

A large number of primary oil and gas reservoirs have been discovered in Proterozoic strata all over the globe. Proterozoic sequences are widely distributed in China, and the discovery of large Sinian-aged gas reservoirs in the Sichuan Basin and Mesoproterozoic liquid oil seepages in North China shows that attention should be paid to the exploration potential of Proterozoic strata. In this paper, the main controlling factors of Proterozoic source rocks are discussed. Principally, active atmospheric circulation and astronomical cycles may have driven intense upwelling and runoff to provide nutrients; oxygenated oceanic surface waters could have provided suitable environments for the organisms to thrive; volcanic activity and terrestrial weathering caused by continental break-up would have injected large amounts of nutrients into the ocean, leading to persistent blooms of marine organisms; and extensive anoxic deep waters may have created ideal conditions for the preservation of organic matter. Additionally, the appearance of eukaryotes resulted in diversified hydrocarbon parent material, which effectively improved the generation potential for oil and gas. Through the comparison of Formations across different cratons, seven sets of Proterozoic organic-rich source rocks have been recognized in China, which mainly developed during interglacial periods and are also comparable worldwide. The Hongshuizhuang and Xiamaling Formations in North China have already been identified previously as Mesoproterozoic source rocks. The early Proterozoic Changchengian System is highly promising as a potential source rock in the Ordos Basin. In the Upper Yangtze area, the Neoproterozoic Datangpo and Doushantuo Formations are extensively distributed, and represent the major source rocks for Sinian gas reservoirs in the Sichuan Basin. Moreover, the Nanhuan System may contain abundant shales with high organic matter contents in the Tarim Basin, although this possibility still needs to be verified. Indeed, all three cratons may contain source rocks of Proterozoic strata; thus, these strata represent major exploration targets worthy of great attention.

Zhao, W., Zhang, S., He, K., Zeng, H., Hu, G., Zhang, B., Wang, Z., Li, Y., 2019. Origin of conventional and shale gas in Sinian–lower Paleozoic strata in the Sichuan Basin: Relayed gas generation from liquid hydrocarbon cracking. American Association of Petroleum Geologist Bulletin 103, 1265-1296.


Large amounts of natural gas have been discovered recently, both in carbonate reservoirs and in shales in the Sinian–Silurian strata of the Sichuan Basin, southern China. Although numerous studies have been conducted to learn about the accumulation of conventional and shale gas, the gas generation history, the origins of the two types of gas, and gas resources in the basin remain unclear. In this study, the hydrocarbon generation histories of Cambrian and Silurian source rocks were reconstructed on the basis of thermal history and hydrocarbon generation kinetic parameters. Intensive cracking of crude oil to generate considerable amounts of secondary cracking gas in Silurian and Cambrian formations occurred during deep burial. The high abundance of overmature pyrobitumen in carbonate reservoirs and shale demonstrates the occurrence of large-scale in situ cracking of liquid hydrocarbons. A mixing model was proposed to quantitatively determine the contribution of kerogen and oil-cracking gas in shale gas accumulations. The mixing of two thermogenic gases with different maturities resulted in a reversal and a rollover of the carbon isotope compositions of shale gas. Moreover, gas resources from the cracking of three occurrence states of liquid hydrocarbons—including dispersed residual bitumen in source rocks, dispersed oil outside the source, and accumulated oil in reservoirs—were evaluated in Sinian–Cambrian and Silurian petroleum systems in the Sichuan Basin, providing a guide for future deep gas exploration of similar formations in China and elsewhere.

Zhao, Z.-Y., Qin, L., Huang, X.-H., Zhang, Y.-Y., Du, M., Xu, X.-B., Zhou, D.-Y., Zhu, B.-W., 2019. Coated direct inlet probe coupled with atmospheric-pressure chemical ionization and high-resolution mass spectrometry for fast quantitation of target analytes. Journal of Chromatography A 1596, 20-29.


The coated direct inlet probe (CDIP) is a new laboratory-made low-cost technology developed from a direct inlet probe (DIP), which has the advantage of quick enrichment/cleanup of an analyte from liquid samples. A capillary probe is coated with hydroxy-terminated polydimethylsiloxane (OH-PDMS), divinylbenzene (DVB), and β-cyclodextrin (β-CD) by a sol-gel method. This probe can be directly coupled with a commercialized atmospheric-pressure chemical ionization (APCI) ion source and high-resolution mass spectrometry, which are widely applicable, reliable, and durable. The ability to perform quantitative analyses with the use of a stable-isotope-labeled internal standard (SIL-IS) was tested by using different concentrations of acenaphthylene (ACY), acenaphthene (ACP), fluorene (FLR), fluoranthene (FLT), phenanthrene (PHE), and benzo[a]pyrene (B[a]P). Calibration curves with a coefficient of determination of R2 ≥ 0.9982 for different polycyclic aromatic hydrocarbons (PAHs) were obtained. A limit of detection (LOD) of 0.008–0.04 ng mL−1 for PAHs was determined. The entire workflow is solvent-free and can be completed in less than 5 min, which demonstrates the advantages of this technique for quantitative analysis.



Archaea are important participants in soil biogeochemical cycles. Their membrane lipids are usually composed of isoprenoid glycerol dialkyl glycerol tetraethers (iGDGTs), which are ubiquitous in the environments and widely applied as biomarkers for archaeal biogeochemical processes and palaeothermometry. However, the biological sources of iGDGTs and environmental factors

controlling their distribution in soils are elusive. We examined the archaeal lipid composition and community structure along an altitudinal soil transect in the Hani terrace wetlands in Southwest of China by combining organic geochemical and high-throughput sequencing approaches. The results show that monoglycosyl -iGDGTs (1G-iGDGTs) are the dominating intact polar lipids (IPLs) and possible precursor of core-iGDGTs preserved in soils. iGDGTs from Hani soils may come from several archaeal lineages based on their significant positive correlations in both core lipids and IPLs. Thaumarchaeota Group I.1b most likely contribute to crenarchaeol and its regio-isomer in non-paddy soils, while Bathyarchaeota, Methanobacteria and Methanomicrobia may predominantly contribute to GDGT-0 in water-saturated paddy soils. Our results indicate that the paleotemperature proxy TEX86 in soils can be affected by changes in archaeal community structure in addition to environmental variables such as soil water content and pH, but not independently by temperature. In addition, the lower TEX86 in humid soils may be partly attributed to the insufficient peak separation of iGDGTs with cyclopentyl moieties, which contain abnormally high abundances of shoulder peaks that may be contributed by anaerobic Archaea. This study sheds light on the increasing role of microbial community structure in affecting the fidelity of TEX86 in terrestrial environment, which should be taken into consideration when applying it to paleo-soil temperature studies.

Zheng, J., Zheng, S.-J., Cai, W.-J., Yu, L., Yuan, B.-F., Feng, Y.-Q., 2019. Stable isotope labeling combined with liquid chromatography-tandem mass spectrometry for comprehensive analysis of short-chain fatty acids. Analytica Chimica Acta 1070, 51-59.


Short-chain fatty acids (SCFAs) are one class of bacterial metabolites mainly formed by gut microbiota from undigested fibers and proteins. These molecules are able to mediate signal conduction processes of cells, acting as G protein-coupled receptors (GPR) activators and histone deacetylases (HDAC) inhibitors. It was reported that SCFAs were closely associated with various human diseases. However, it is still challenging to analyze SCFAs because of their diverse structures and broad range of concentrations. In this study, we developed a highly sensitive method for simultaneous detection of 34 SCFAs by stable isotope labeling coupled with ultra-high performance liquid chromatography-electrospray ionization-mass spectrometry (UHPLC-ESI-MS/MS) analysis. In this respect, a pair of isotope labeling reagents, N-(4-(aminomethyl)benzyl)aniline (4-AMBA) and N-(4-(aminomethyl)benzyl)aniline-d5 (4-AMBA-d5), were synthesized to label SCFAs from the feces of mice and SCFA standards, respectively. The 4-AMBA-d5 labeled SCFAs were used as internal standards to compensate the ionization variances resulting from matrix effect and thus minimize quantitation deviation in MS detection. After 4-AMBA labeling, the retention of SCFAs on the reversed-phase column increased and the separation resolution of isomers were improved. In addition, the MS responses of most SCFAs were enhanced by up to three orders of magnitude compared to unlabeled SCFAs. The limits of detection (LODs) of SCFAs were as low as 0.005 ng/mL. Moreover, good linearity for 34 SCFAs was obtained with the coefficient of determination (R2) ranging from 0.9846 to 0.9999 and the intra- and inter-day relative standard deviations (RSDs) were <17.8% and 15.4%, respectively, indicating the acceptable reproducibility of the developed method. Using the developed method, we successfully quantified 21 SCFAs from the feces of mice. Partial least squares discriminant analysis (PLS-DA) and t-test analysis showed that the contents of 9 SCFAs were significantly different between Alzheimer's disease (AD) and wide type (WT) mice fecal samples. Compared to WT mice, the contents of propionic acid, isobutyric acid, 3-hydroxybutyric acid, and 3-hydroxyisocaleric acid were decreased in AD mice, while lactic acid, 2-hydroxybutyric acid, 2-hydroxyisobutyric acid, levulinic acid, and valpronic acid were increased in AD mice. These significantly changed SCFAs in the feces of AD mice may afford to a better understanding of the

pathogenesis of AD. Taken together, the developed UHPLC-ESI-MS/MS method could be applied for the sensitive and comprehensive determination of SCFAs from complex biological samples.



Understanding dynamic profiles of tar in coal pyrolysis is vital to high quality chemical production and upgrading process of tar, which is difficult to be accessed experimentally. Using large coal models with reasonable distribution of functional groups, ReaxFF MD method can shed light on comprehensive structures and reaction details of coal tar in pyrolysis, which complements available experimental observations. In this work, a large model with 98,748 atoms of Naomaohu low-rank coal is constructed to explore tar behaviors for the first time computationally by heat-up ReaxFF MD simulations at 500–2500 K. The correspondence between the tar behaviors and the divided four pyrolysis stages observed would be very helpful for modulating the composition and yield of tar and the subsequent upgrading process. The dynamic profiles of bridge bonds, ring intermediates and the detailed structures of hydrocarbons in tar (C5–C40 fragments) are revealed, which shows that the five- and seven-membered ring intermediates in tar should be soot precursors during coal pyrolysis process. The increasing trend of –O–(CH2)n– is strongly related to low-temperature cross-linking reactions during low-rank coal pyrolysis, while the increasing trend of Car–Car plays a significant role in recombination reactions at high temperature. Moreover, the simulation also shows that the production of aliphatic hydrocarbons is favored at the primary pyrolysis stage, accompanied with high concentration of oxygenated compounds produced, while aromatic fragments are most likely generated at the secondary pyrolysis stage where the amount of phenolic products tends to decrease.

Zhou, G., Wei, G., Hu, G., 2019. The geochemical and organic petrological characteristics of coal measures of the Xujiahe formation in the Sichuan Basin, China. Energy Exploration & Exploitation 37, 889-906.

https://doi.org/10.1177/0144598719842332

Upper Triassic coaly and lacustrine source rocks complicate efforts to determine the source of hydrocarbons in Sichuan Basin. Total organic carbon analyses, pyrolysis experiments, petrological examinations, and gas chromatography and gas chromatography?mass spectrometry determinations were conducted on coals, carbonaceous mudstones and mudstones collected from two outcrop sections and cores of nine wells. Results revealed that the abundant organic carbon content will prolong the hydrocarbon generation cycle for coals and then the hydrocarbon generating capacity of coals will be enhanced by salinization, thereby contributing bacteria and algae microorganisms into humic coal of the Xujiahe Formation. Compared with mudstone, coal with the same maturity has a stronger adsorption effect on free hydrocarbons. When Ro is greater than 1.35, coal still has a strong hydrocarbon generation ability. The stable water column stratification and euxinic bottom water conditions are evidenced from the lower Pr/Ph and the higher gammacerane indices. The mixing of sea water has been proven by the existence of 4α,23,24,-trimethylcholestanes.

Zhou, S., Zhang, D., Wang, H., Li, X., 2019. A modified BET equation to investigate supercritical methane adsorption mechanisms in shale. Marine and Petroleum Geology 105, 284-292.


Although the Brunauer-Emmett-Teller (BET) equation is a classic adsorption model for describing the adsorption of gases in adsorbents, it cannot be applied in supercritical conditions because the saturation vapor pressure (p0) in this equation is not defined when T > Tc. In this study, a modified BET equation is proposed, and can be applied to investigate supercritical methane adsorption mechanisms in shale by using density instead of pressure in this equation. The observed (excess) high-pressure methane adsorption isotherms always can be well-fitted by the modified BET model when the adsorbed-phase density (ρa) is not fixed. The fitted results show that the number of adsorption layers (n) ranges from 1.79 to 2.42, with an average value of 2.12, indicating a double-layer adsorption mechanism approximately. Moreover, we compare this novel model with the commonly used Langmuir and DR models, and find that all the three models can fit the excess adsorption isotherms equally well. However, a critical advantage of this new model is that it can calculate the number of adsorption layers (n), while other models cannot. It is this advantage that makes it possible to analyze the shale gas adsorption mechanism experimentally. Moreover, the average number of adsorption layers (θ) is much smaller than the number of adsorption layers (n), indicating that there are many empty adsorption sites in the adsorption space and the density of the second layer must be less than the first layer, which is consistent with the molecular simulation results.

Zhou, Y., Zhang, H., Wang, X., Qi, D., Gu, W., Wu, D., Liu, B., 2019. Development of a heart-cutting supercritical fluid chromatography-high-performance liquid chromatography coupled to tandem mass spectrometry for the determination of four tobacco-specific nitrosamines in mainstream smoke. Analytical and Bioanalytical Chemistry 411, 2961-2969.

https://doi.org/10.1007/s00216-019-01746-w

This paper proposed a newly developed heart-cutting two-dimensional supercritical fluid chromatography-high-performance liquid chromatography system coupled to tandem mass spectrometry (SFC-HPLC-MS/MS) for the determination of four tobacco-specific nitrosamines (TSNAs) in cigarette mainstream smoke. The orthogonality of five SFC columns and two HPLC columns was evaluated. The 1-AA column was applied for the first dimensional (1D) SFC separation to isolate the target compounds from the complex cigarette smoke matrices, and a trapping column in conjunction with an isocratic pump was employed to capture the 1D elutes. Then, the trapped 1D elutes were transferred into the C18 column through a two-position/six-port valve for the second dimensional (2D) analysis. The ion suppression was significantly reduced by the established SFC-HPLC system; meanwhile, the matrix interferences were eliminated as the results demonstrated. A dynamic range between 0.1 and 20 ng/mL was achieved with LOQs of 0.72 μg/cig for N-nitrosonornicotine (NNN), 0.66 μg/cig for nicotine-derived nitrosamine ketone (NNK), 0.81 μg/cig for N-nitrosoanatabine (NAT), and 0.39 μg/cig for N-nitrosoanabasine (NAB). All the results revealed that the presented method exhibited good repeatabilities and recoveries and could be used as a rapid and reliable approach for routine analysis of TSNAs in mainstream smoke.

Zhu, C., Zhou, R., Zhang, Y., Chen, J., Tang, S., Li, X., Zeng, X., 2019. The detection of petroleum contaminants in soil based on multiphoton electron extraction spectroscopy. Analytical Methods 11, 2611-2616.

http://dx.doi.org/10.1039/C9AY00308H

The fast detection of petroleum contaminants in soil is very important and urgent for environmental monitoring. Generally, the current methods for the detection of these kinds of contaminants require complex sample pre-treatment with the excessive use of toxic and volatile organic solvents or the

analytical performances are not satisfactory enough for field-based applications. A method based on photocurrent measurements, named multiphoton electron extraction spectroscopy (MEES), was proposed to detect petroleum contaminants in a soil matrix in this study. The results showed that the resonance-excited wavelength of 326 nm had the highest selectivity for petroleum determination after a wide range of wavelengths was scanned with an optical parametric oscillator (OPO) laser under ambient conditions. Linear regression was performed to fit the intensities and areas of the photocurrent curves to the petroleum concentration via a least squares method. A LoD of 0.0091 wt% was achieved with an R2 value of 0.9912 and a RMSECV value of 0.013 wt% via the peak area approach, whose sensitivity and accuracy were slightly higher compared to the peak intensity method (LoD of 0.011 wt%, an R2 value of 0.9315 and a RMSECV value of 0.020 wt%). This research provided us with a new method for the rapid determination of petroleum contaminants in soil samples with high accuracy.



Significant petroleum resources occur in the Ordovician carbonate reservoirs of the Tazhong area (Tarim Basin, China) in accumulations of black oil, volatile oil and condensate. However, the factors controlling the distribution of pools with different fluid phases remain poorly understood. Here, we integrate geological and conventional oil/gas geochemical data with an extensive dataset on diamondoids and propose a model for the occurrence of petroleum fluids in the area. Oils in the study area contain low variety and concentration of diamondoids and organic-sulfur compounds (OSCs) and have oil-dissolved wet gas mostly co-generated with oil. In contrast, liquids in the condensate reservoirs are significantly enriched in various types of diamondoids and OSCs, and have dry associated gas with methane enriched in 13C and relatively high content of H2S. We interpret that mature gas from deeper Cambrian strata, likely generated from thermally cracked oils and affected by thermochemical sulfate reduction (TSR), invaded the condensate reservoirs. Black oil reservoirs did not receive this late gas charge and this preserved their oil phase. The 1D burial history models and data on fluid inclusions suggest that oil charged all studied Ordovician reservoirs in the Late Permian – Triassic time, while the late gas charge occurred in selected reservoirs in the Late Himalayan time (∼10 Ma). Diamondoids proved to be useful indicators of the late gas charge as their variety and concentrations in liquids from the study area show good correlation with the extent of gas invasion.

Zhu, M., Li, M., Wei, S., Song, J., Hu, J., Jia, W., Peng, P.a., 2019. Evaluation of a dichromate oxidation method for the isolation and quantification of black carbon in ancient geological samples. Organic Geochemistry 133, 20-31.


The dichromate oxidation method is widely used in measurements of black carbon (BC) in geological sediments. The separation of organic carbon (OC) and BC is a critical step in the procedure. A comprehensive evaluation of the dichromate oxidation method was conducted using three types of kerogen with different maturities and two charcoal samples. The residues of each kerogen/BC oxidized under different conditions were quantified to determine the remaining C content. The results showed that the traditional dichromate oxidation method (0.1 M KK2Cr2O2/2 M H2SO4) was reliable when the geological sediments contained a Type I kerogen with low maturity (Ro ≤ 0.50%). We compared the dichromate oxidation method under different oxidation times and oxidant concentrations for the separation of OC and BC. The extension of oxidation time improved the

removal of all three types of kerogen, but Type I kerogen with high maturity and Types II and III kerogen, still significantly interfered with the isolation of BC in geological sediments. The concentrations of oxidant necessary were tested and indicated that an increase in oxidant concentration significantly improved the separation of BC and OC, and a high concentration of 0.5 M K2Cr2O2/2 M H2SO4 and 300 h oxidation time at 55 °C was effective for the isolation of BC in geological samples. The results of this study also indicated that the stable C isotope values of the remaining C were not affected by the isolation of BC with the dichromate method and that the method can therefore be used for the stable C isotope measurements of BC in geological sediments.

Zhu, Q.-F., Zhang, T.-Y., Qin, L.-L., Li, X.-M., Zheng, S.-J., Feng, Y.-Q., 2019. Method to calculate the retention index in hydrophilic interaction liquid chromatography using normal fatty acid derivatives as calibrants. Analytical Chemistry 91, 6057-6063.


Hydrophilic interaction liquid chromatography–mass spectrometry (HILIC-MS) is a complementary technique to reversed-phase liquid chromatography–mass spectrometry (RPLC-MS) and has been widely used to expand the coverage of the metabolome in MS-based metabolomics. However, the use of HILIC retention time (HILIC RT) in metabolites annotation is quite limited because of its poor reproducibility. Here, we developed a method to calculate the retention index in HILIC (HILIC RI) for calibration of HILIC RT. In this method, a mixture of 2-dimethylaminoethylamine (DMED)-labeled fatty acid standards with carbon chain length from C2 to C22 were selected as calibrants to establish a linear calibration equation between HILIC RT and carbon number for the calculation of HILIC RI. The calculated HILIC RIs based on a regression equation could efficiently calibrate the retention time shifts for 28 DMED-labeled carboxyl standards and DMED-labeled carboxyl metabolites in rat urine, serum and feces on a HILIC column with different gradient elution conditions. Furthermore, the developed HILIC RI strategy was applied to RT calibration of screened metabolites, the annotation of isomers in HILIC-MS-based metabolomics analysis for real samples, and the correction of isotope effects in chemical isotope labeling HILIC-MS analysis. Taken together, the resulting HILIC RI strategy is a promising analytical technique to improve the accuracy of metabolite annotation; it would be widely used in HILIC-MS-based metabolome analysis.

Zhu, R., Zou, C., Mao, Z., Yang, H., Hui, X., Wu, S., Cui, J., Su, L., Li, S., Yang, Z., 2019. Characteristics and distribution of continental tight oil in China. Journal of Asian Earth Sciences 178, 37-51.


Tight oil in China is mainly distributed in Mesozoic-Cenozoic continental petroliferous basins, either generally occurs in tight sandstone or tight carbonate reservoirs which are paragenetic to or in contact with lacustrine petroleum source rocks. By the end of 2016, the continental tight oil in China has established an annual production capacity of 1.55 million tons, and a cumulative oil production of 2.52 million tons. In 2016, the continental tight oil production in China was about 800,000 tons. By analyzing the characterization of the tight oil in Ordos Basin, Songliao Basin, Jungar Basin, the organic-rich shale in China were formed in multiple geological periods including the Permian, Triassic, Jurassic, Cretaceous, Neogene, and Paleogene, in freshwater, semi-saline to hyper-saline lacustrine depositional setting. They are generally tens of meters to several hundreds of meters thick, have total organic carbon (TOC) contents of 0.4–16%, and thermal maturity of 0.4–1.4%. Algal bloom as results of volcanism, low sedimentation rate, transgression, and stratification of water body are prominent factors controlling the formation of organic-rich shales. Tight oil reservoirs in China

mainly include tight sandstone, tight carbonate rock, tight sedimentary tuff, etc., all of which are characterized by strong heterogeneity and poor petrophysical properties, with in situ porosity and permeability generally no more 12% and 1 × 10−3 μm2 respectively. They are also characterized by tight pore-throat systems of nano- to micro-scales, with pore throat diameters in the range of 80–1800 nm, and complex pore structures. The producing reservoirs have pressure coefficients between 0.7 and 1.8, covering under-pressure to over-pressure. Crude oil properties vary greatly with densities ranging from 0.75 to 0.92 g/cm3. It is believed that the abundance and effectiveness of hydrocarbon supply controls the formation of oil saturation, and tight oil “sweet spots” are generally in or near the areas with high hydrocarbon expulsion intensities. In addition, the quality of the source rock and the type of source reservoir control the distribution of the “sweet spots”, and storage space and movable fluid guarantee the formation of the “sweet spot” area of high oil saturation. “Sweet spots” are often developed in local mini-structural highs under a broad and gentle-sloped background. Continental tight oil in China has estimated geological resource of 14.66 × 109 tons with a technically recoverable resource of 1.45 × 109 tons. Tight oil is mainly distributed in Ordos Basin, Songliao Basin, Bohai Bay Basin, Junggar Basin, and Qaidam Basin, within the Mesozoic and Cenozoic formations. Overall China has a relatively large tight oil reserve and good exploration prospect.

Zou, C., Yang, Z., Zhu, R., Wu, S., Fu, J., Lei, D., Hou, L., Lin, S., Pan, S., 2019. Geologic significance and optimization technique of sweet spots in unconventional shale systems. Journal of Asian Earth Sciences 178, 3-19.


Crude oil in unconventional shale systems, present as tight oil and shale oil, accumulates inside an oil kitchen in formations with coexistent sources and reservoirs. Organic matter present in oil shale is not yet mature and requires heating to convert it into crude oil. Oil exploration in shale systems involves the exploration of shale oil retained in source rocks and tight oil rich zones located near source rocks. Tight oil is a type of realistic unconventional oil resources in China. The marked increase in potential shale oil reserves, and exploration of these reserves, will result in a shale oil revolution similar to that experienced for shale gas. Based on a systematic comparison of geologic features of shale systems in the US and China, the geologic significance of the sweet spots in shale systems is proposed. This zone contains an abundance of unconventional oil in shale systems that can be explored and developed under current economic and technical conditions. The sweet spot zone refers to the zone in the tight oil rich zone which has industrial value within the scope of matured high-quality source rocks on the plane. The sweet spot interval refers to the high-productivity interval of tight oil which has industrial value through artificial stimulation. The main aim of oil exploration in shale formations is to identify the sweet spots. The distribution of the economic sweet spots in shale systems is evaluated by overlapping the geologic, engineering and economic sweet spots. Resource assessment techniques, the identification of logging data properties, high-resolution 3D seismic surveys, horizontal well production from well pads, and artificial reservoir development of sweet spots in oil-bearing shale formations can assist efficient development of oil. Globally, shale formations contain a significant volume of oil reserves. Currently, stimulated reservoir volume (SRV) techniques in horizontal wells in marine shale gas formations in the United States have average peak-productivity cycles of 10–15 years. To achieve commecial oil production in lacustrine shale systems in China, it is important to utilize large formation thicknesses and the high abundance of organic matter. In addition, the development of practical and economic techniques will result in an increase of productivity of tight oil and shale oil by 30–50 million tons, as well as the economic development of oil in lacustrine shale systems in China.



Low-rank coal reserves account for nearly 55% of the national coal reserves in China, and it is extremely important to understand their anisotropic microstructure and coalbed methane storage and sorption characteristics. In this study, microstructures that develop parallel to and perpendicular to bedding of low-rank coals are studied through scanning electron microscopy. The micromorphology and microfracture and mineral distributions are examined. Based on fractal theory and digital image processing technology, the fractal box-counting dimensions of microfracture distributions that form parallel as well as perpendicular to the coal bedding planes are calculated, and the anisotropic fractal characteristics of these microfracture distributions are characterized. The pore-size distribution and the fractal characteristics of the microscopic pore structure are systematically examined by means of nitrogen adsorption and mercury intrusion tests. The results of the fractal box-counting dimension calculations indicate that microfractures distributed perpendicular to coal bedding are rougher and more irregular than those distributed along a bedding plane, with the former exhibiting higher space filling and methane adsorption capacity. The fractal dimension of the microscopic pore structure reveals two inflection points measuring approximately 5 and 80 nm, thereby indicating that the low-rank coal exhibits a microscopic pore structure with a three-level fractal characteristic.

Zou, Y., Liu, D., Zhao, F., Kuang, H., Sun, Y., Cheng, J., 2019. Chemostratigraphy of the Mesoproterozoic Shennongjia Group, Yangtze Craton (South China): Implications for oxidized shallow seawaters. Journal of Asian Earth Sciences 179, 399-415.


The relatively low Mesoproterozoic oxygen concentrations in atmospheric and marine environments remained controversial because the marine chemical evolution has not been sufficiently researched. To provide a better understanding of the secular redox conditions of shallow-water sedimentary environments and to perform global isotopic comparisons, we present new data of rare earth elements and yttrium (REE + Y), redox-sensitive elements (RSEs), and carbonate carbon-oxygen isotopes from Mesoproterozoic marine succession in the Shennongjia Group of the Yangtze Shennongjia area. Seawater-like REE + Y distribution patterns with significantly negative Ce anomalies, which had previously been screened to avoid detrital effects in the leached carbonates, illustrate the oxidation of shallow seawaters during the deposition of this group. Although the Ce/Ce* and (Pr/Yb)SN values remain relatively low in carbonate samples throughout the Mesoproterozoic, these values are higher than those of the modern oxygenated ocean, indicating less intense oxygenation. This conclusion is supported by the high enrichment factors of the RSEs in screened samples resulting from a considerable marine reservoir for dissolved RSEs in a constantly oxidized environment. Under these circumstances, the δ13Ccarb chemostratigraphy is moderately varied, with values near +3.5‰ and lower than +5‰, and more dynamic variability is observed over time, which is related to progressively smaller marine dissolved inorganic carbon (DIC) reservoirs. In addition, the significant negative excursion of δ13Ccarb near to or less than 0‰ in this lower subgroup is globally matched in different blocks and may correspond to the oxidation of isotopically light organic matter in oceans. A worldwide comparison indicates that the δ13Ccarb chemostratigraphies combined with limited geochronological data may constrain this extended negative excursion to ca. 1.3–1.2 Ga and the Shennongjia Group to ca. 1.3–1.1 Ga.

Documents

eaogorg.files.wordpress.com€¦ · Web viewGEOCHEMISTRY ARTICLES – May 2019. Analytical Chemistry. Fallaise, D., Konzuk, J., Cheyne, C., Mack, E.E., Longstaffe, J.G., 2019. Nontargeted