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Joint Annual Meeting - Congrès annuel conjoint

TABLE OF CONTENTSTABLE DES MATIÈRES

ABSTRACTS / RÉSUMÉS.............................................................................................................................. 1AUTHOR INDEX / INDEX DES AUTEURS ............................................................................................ 241

Abstracts can also be searched using this link /Les résumés peuvent aussi être consultés sur le site suivant :http://gac.esd.mun.ca/gac_2011/search_abs/program.asp

Abstracts Volume 34 / Volume des résumés 34ISBN: 978-1-897095-55-3ISSN: 0701-8738Printed in Canada / Imprimé au CanadaPublisher / Éditeur: Geological Association of Canada / Association géologique du Canada © 2011

ttawa 2011ttawa 2011GAC®/AGC® - MAC/AMC - SEG - SGA

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TRACE ELEMENT GEOCHEMISTRY OF MAGNETITEAND ITS RELATIONSHIP TO MINERALIZATION INTHE GREAT BEAR MAGMATIC ZONE, NWT, CANADA— PRELIMINARY FINDINGS

Acosta Góngora, P., pedro1@ualberta.ca, Gleeson, S.A, University ofAlberta, Saskatchewan Dr., Edmonton, AB T6G 2E3, Ootes, L.,Jackson, V.A., Northwest Territories Geoscience Office, 4601-B St.,Yellowknife, NT X1A 2R3, Samson, I.M., University of Windsor, 401Sunset Avenue, Windsor, ON N9B 3P4, and Corriveau, L., GeologicalSurvey of Canada, 490 De la Couronne St., Quebec City, QC G1K 9A9

The Paleoproterozoic Great Bear magmatic zone is the focus ofongoing exploration for iron oxide copper-gold (IOCG) mineral-ization. Examples include the Sue-Dianne and NICO deposits.This project aims to characterize the nature and geochemistry ofthe fluids responsible for the mineralization in these deposits andother similar prospects in the southern part of the region.

Petrographic and hand specimen descriptions of 45 samplesprovides a preliminary paragenetic sequence for the DAMP, FAB,and Nori prospects and the NICO and Sue Dianne advanced ex-ploration projects. Mineralization at DAMP, FAB and Sue Dianne(Cu±Ag, U) are hosted by brecciated felsic volcanic rocks andcharacterized by an early stage of hematite and magnetite, fol-lowed by the deposition of chalcopyrite, bornite, and chalcociteas the main Cu ore minerals. The FAB showing contains two gen-erations of magnetite; an older phase disseminated on the breccialithoclasts and a younger phase found as the matrix to the brecciaand veins. At Nori (Cu-Mo-U), tourmaline-biotite-uraninite veinscrosscut the Treasure Lake metasedimentary rocks and also havetwo generations of magnetite; early phase disseminated in the wallrock and a later phase occurring in veins with K-feldspar coevalwith molybdenite, uraninite, and chalcopyrite mineralization. Atthe NICO (Au-Bi-Co-Cu) deposit, the ore minerals are hosted byhydrothermally altered metasedimentary rocks of the TreasureLake Group. Several generations of magnetite have been recog-nized and include pre- (strata bound magnetite replacement), syn-(magnetite in arsenopyrite-bearing veins, vein selvages andbreccias, and/or strongly overprinting the host metasedimentarybedding) and post-mineralization (late-stage magnetite veins)episodes. Thus, magnetite is found in all the mineral showings andadvanced exploration projects within this area, and it is oftenclosely related to mineralized rocks.

We present the results obtained by an electron microprobeanalyses and suggest that the trace elements in magnetite, espe-cially V, have a significant variation between the differentprospects and advanced exploration projects. Furthermore, localvariations in V and Co, can be used to distinguish between pre-and syn-mineralization magnetite. This study indicates that thetrace element signature of magnetite may be a suitable tool formineral exploration in the GBmz. Future analytical investigationsutilizing ICP-MS will be carried out to constrain the results re-ported here.

THE INFLUENCE OF THE OTTAWA-BONNECHEREGRABEN ON NEOTECTONICS, CONTEMPORARYSEISMICITY, AND SEISMIC HAZARD

Adams, J., Canadian Hazards Information Service, Geological Surveyof Canada, 7 Observatory Crescent, Ottawa, ON K1A 0Y3

The Ottawa-Bonnechere Graben (OBG) is a major weakness inthe integrity of the Canadian Shield and influences the contempo-rary pattern of seismicity. The largest historical earthquake wasmagnitude 6.2 at Timiskaming in 1935. One of the younger tec-tonic disturbances near the OBG was the passage of Western Que-bec over the Great Meteor hotspot. This likely caused the

migrating domal uplift of western Quebec leading to the erosionof overlying Cambrian-Devonian platform sediments that are stillpreserved in the Ottawa Valley where they were downfaulted intothe OBG (similar rocks are preserved by downfaulting at the northend of Lake Timiskaming, and seismicity suggests that the OBGstructure might extend 400+ km NW of Mattawa to include a lin-ear cluster of deep earthquakes near Cochrane). There was ~1 kmof uplift and erosion at Montreal (evidence: xenolithic Devonianrocks in Monteregian volcanic throats) and the domal uplift is hy-pothesized to have caused extensional reactivation of existing pre-Cambrian and early rifting faults near its NW-SE path ~110 m.y.ago. Carbonatite dykes were intruded into Ottawa limestones atthat time, and the regional uplift may have reactivated the OBGstructures, as evinced by a 102 ± 3 Ma date on vuggy calcite and100 ± 1 Ma date on pyrite/calcite (both dates by Pat Smith, Univ.Toronto) in multiphase joint-controlled veins in the Ordovicianlimestone. Sub-horizontal slickensides on some of the vein fillingsin the Ottawa area indicate a period of strike-slip faulting on thenormal faults; if the sheared veins postdate the dated vuggy veinsthey indicate this strike-slip period was Cretaceous or younger(the sheared calcite itself has not yet been dated). Stress relief isongoing, as shown by earthquakes, pop-ups, quarry floor buckles,and offset bore holes in Ottawa-area excavations. While indirect(shaking) evidence for postglacial paleo-earthquakes is knownfrom the Alfred region (Aylsworth) and from near the north endof Lake Timiskaming (Adams), and there have been some postu-lated young faults (Eyles, Fenton/Adams) at the north end of LakeTimiskaming, no seismogenic postglacial fault has yet beenproven. Understanding the origin and evolution of the OBG wouldbe beneficial to contemporary hazard estimation. Current modelsfor seismic hazard estimation consider that the current clusteredactivity will continue, but that large earthquakes will occur (andtherefore have already occurred!) anywhere along the OBG.

CONSTRAINING THE ORIGIN OF METALENRICHMENT IN THE BUSHVELD COMPLEX, SOUTHAFRICA: A FLUID AND MELT INCLUSION STUDY OFPEGMATITES BELOW THE MERENSKY REEF

Adlakha, E.E. and Hanley, J.J., Saint Mary's University, Halifax, NSB3H 3C3, erinadlakha@gmail.com

Pegmatites in the Bushveld Complex occur as veins and pipes com-prised of quartz-andesine-biotite intergrowth. Mineral thermome-try indicates minimum equilibration temperatures of 610-740ºC,corresponding to the recrystallization (or alteration) of the sur-rounding cumulate wall rocks during pegmatite formation. Moss-bauer spectroscopy and wet titration determination of the Fe3+:Fe2+

ratios in biotite grains constrain the ƒO2 during biotite crystalliza-tion to ΔFMQ±1. The δ37Cl values for biotite range from -0.15‰to 0.84‰, consistent with a mantle source for the Cl. Laser40Ar/39Ar dating of biotite grains indicates that the pegmatites crys-tallized from 2044 (±23) Ma to 2023 (±12) Ma. The range in crys-tallization age indicates that late stage volatile activity persisted inthe intrusion for a considerable period of time. The cores of thepegmatites may contain base metal sulfides with inclusions of pre-cious metal minerals including melonite [(Ni, Pd) Te2] and hessite.Normative abundance patterns for the pegmatite sulfides are mostsimilar to those of the Platreef, showing a marked enrichment inPd and Au relative to Pt (Pd:Pt > 8), Cu enrichment relative to Ni(Cu:Ni > 20) and significant depletion in Ir.

Quartz and plagioclase within the pegmatites contain primaryfluid inclusions, ranging from early low salinity two-phase aque-ous to late, ultrahigh salinity (nearly anhydrous; >98 wt% NaCl

ABSTRACTS / RÉSUMÉS

equivalent) halide melt inclusions composed of NaCl-CaCl2.Later generations of secondary halite-bearing inclusions [28.4-35.3 wt% NaCl equiv.; Th=115-259ºC (by halite dissolution;n=58)] and halite-undersaturated [15.4-20.5 wt% NaCl equiv.;Th=128 and 320ºC (by vapour-out; n=7)] were observed. Silicatemelt inclusions containing a high K rhyodacitic liquid are alsopresent. Co-entrapment of halide and silicate melt in single in-clusions was observed, confirming that the silicate melt was sat-urated in a saline volatile phase. Trace element modeling showsthat the pegmatites formed by very low degrees of fractional crys-tallization (~1 vol%) of the silicate liquid trapped in the inclusions.Analyses of single melt inclusions by LA-ICP-MS indicate highconcentrations of Pd and Au (0.2-0.6 ppm range) at the time oftheir entrapment. These observations provide direct evidence thatrelatively oxidized halide melt-saturated silicate residues of mag-matic origin were PGE-bearing at the time of their entrapment.Ore metal ratios in the melt inclusions and pegmatite sulfides areconsistent with the bulk metal ratios of the pyroxenite cumulatesbelow the Merensky Reef. This suggests that metals were scav-enged from those cumulates.

U-Th-4He DATING OF CARBONATES: A REVIVAL? THECASE OF THE BEAR CAVE FLOWSTONE, NORTHERNYUKON, CANADA

Agosta, S.1, sagosta@uottawa.ca, Pinti, D.L.2, Mohapatra, R.3,Ghaleb, B.2, Sano, Y.4, Lauriol, B.1 and Clark, I.D.5, 1Department ofGeography, University of Ottawa, Ottawa, ON; 2GEOTOP,Département des sciences de la Terre et de l’atmosphère, UQAM,Montréal, QC; 3MAPL Noble Gas Laboratory, Dept. of Earth Sciences,University of Ottawa, ON; 4Atmospheric and Ocean ResearchInstitute, University of Tokyo, Kashiwa, Japan; 5Department of EarthSciences, University of Ottawa, Ottawa, ON

Bear Cave, on the Arctic Circle in the north-western Yukon Terri-tory, hosts rare, high latitude speleothem. Isolation from glacialadvance has allowed for the preservation of a 68 cm thick flow-stone (BC1), likely of Tertiary age. Unique deposits such as theseattract interest in their potential for paleoenvironmental and pale-oclimatic reconstruction at high latitude, and their insight into theconditions in Beringia prior to the establishment of permafrost.Dating this speleothem formation is critical in order to elucidatepaleoclimatic variations inland at high latitudes. Initial230Th/234U/238U dating was unsuccessful as the system was atsecular equilibrium, thus the age is greater than 400 ka. U-Th-4Hehas been used in the past for dating corals and was explored to ob-tain an absolute age on the flowstone from Bear Cave. Samplesof primary unaltered calcite were crushed to a powder and gas wasextracted by stepwise heating to 700°C at GEOTOP-UQAM. 4Hemeasured was calibrated against a pure 3He spike using a quadru-pole mass spectrometer at the University of Tokyo. Significant re-lease of 4He observed between 400 and 600°C suggests theretention of radiogenic helium in the carbonate grains. The con-tents of 238U and 232Th were measured on separate aliquots byTIMS at GEOTOP. Additional experiments were carried out at theMAPL Noble Gas Laboratory-University of Ottawa for compari-son on a replicate section (BC1-4Base). Gas extraction was carriedout by step heating crystal separates in ultrahigh vacuum from 50to 600°C, where the helium isotopes were measured on aMAP215-50 noble gas mass spectrometer. Experiments also con-firmed that 4He is retained at ambient conditions. U and Th con-centrations were measured on residual material by ICP-MS.Results from MAPL were similar to those reported at GEOTOP.4He range was found to be from 2.05 × 10-8 to 3.18 × 10-7ccSTP/g. The 238U content varies between 0.194 and 0.271 ppmand 232Th ranges between 1.35 and 7.81 ppb. Resulting U-Th-4Hecalculated age for BCI-4Base is 9.70±0.70 Ma (GEOTOP), and

9.35±0.52 Ma (MAPL). These ages are congruent to those derivedfor other sections in the profile of the flowstone. Future work willbe focused on refining the procedure to improve the chronologyon the BC1 flowstone. Nevertheless, preliminary data from thepresent study support a revival of the U-Th-4He chronology andits applications in paleoclimatic reconstructions of other Tertiary-aged speleothems.

FORMATION OF THE CENTENNIAL UNCONFORMITY-RELATED URANIUM DEPOSIT IN THESOUTH-CENTRAL ATHABASCA BASIN, CANADA

Alexandre, P., alexandre@geol.queensu.ca, Kyser, T.K., Queen'sUniversity, Kingston, ON K7L 3N6, Jiricka, D. and Witt, G., CamecoCorporation, 2121-11th Street West, Saskatoon, SK S7M 1J3

The Centennial U deposit is situated in the south-central AthabascaBasin (Canada), and straddles the unconformity between early Pa-leoproterozoic to Archean metasedimentary and metavolcanicrocks and granitoids, and the clastic sediments of the Paleopro-terozoic Athabasca Group. Although it has most characteristics ofa unconformity-related uranium deposit, the Centennial deposit isatypical in that it is not directly associated with an EM conductor(there is a paucity of graphite in the basement) or with a major re-verse fault zone; it is distal from a major fluid conduit (~300 to~400 m from the Dufferin Fault), it has low Ni, Cu, Co, Zn, andPb contents, and contains a unusually large amount (up to 5 %) ofsecondary uranyl minerals. Additionally, a network of diabasedykes and sills is observed at Centennial, seemingly intruding themain U mineralization of massive uraninite based on the relativelysharp contacts between the diabase dyke and the high-grade ore.

The pre-ore alteration assemblage at Centennial includeskaolinite, illite, and sudoite, which have been formed by fluidswith isotopic and chemical compositions that are comparable withthose from other sandstone-hosted unconformity-type U depositsin the Athabasca Basin. Pre-ore illite-related fluids have δ18O of~3‰ and δD of approximately –40‰, whereas pre-ore chlorite-related fluids have δ18O between 1.7 and 4.3‰ and δD between -18 and 1‰.

Laser ablation ICP-MS U/Pb dating of the various U phasesindicates that initial mineralization, represented by disseminateduraninite found directly to the north of the Centennial deposit s.s.,occurred at ca. 1.6 Ga. The main ore, represented by massive andstrongly altered uraninite, followed at an unknown time. A minor(

ventional plots, implying a continental arc setting. Many base andprecious metals deposits occur in TCR some with ancient miningrecords. The TCR has been under systematic exploration in thelast 10 years. Four deposits, Cheshmeh-Hafez (Pb>Cu>>Au-Ag),Gandi (Pb-Zn>Cu-Au+Ag), Qoleh-Kaftaran (Pb>>Zn>>Cu-Ag),and Chah-Mosa (Cu only), are selected as representatives of thevarious deposits in TCR, for sulfur isotope studies. Qoleh-Kaf-taran includes several galena-sphalerite-chalcopyrite bearingquartz-barite veins hosted in andesitic lava flows and a quartz-monzodiorite pluton. Cheshmeh Hafez consists of four mainquartz veins containing galena and subordinate chalcopyrite, spha-lerite, bornite, pyrite, and tetrahedrite in basaltic andesite anddacite. Gandi consists of numerous small veins of quartz contain-ing variable galena, sphalerite, barite, pyrite and chalcopyrite inpyroclastic rocks. Chah-Mosa, consists of chalcocite-bearingquartz veins and veinlets in a shallow porphyritic quartz-monzo-diorite intrusion.

Some 30 samples from the four deposits were analyzed forsulfur isotope values at the GG-Hatch Lab, University of Ottawa.The δ34S values for Gandi (galena-sphalerite), Cheshmeh-Hafez(galena-chalcopyrite), Chah-Mosa (chalcocite), and Qoleh-Kaftaran(galena-sphalerite) vary between -1.4 to -5.2, +0.5 to -1.3, -5.4 to -7.5, and -6.4 to -9.1 per mil, respectively. The δ34S values for orefluids in equilibrium with the sulfide minerals fall in the range -1.3to -7.5, -1.6 to +4.1, -0.3 to -5.1, and -5.5 to -9.1 per mil, respec-tively. The δ34S values for barite from Gandi and Qoleh Kaftaranvary between +15.0 to +16.0, and +8.3 to +9.4 per mil, respectively.

The ore and gangue minerals, textures, hydrothermal alter-ations, and TH values, are typical of epithermal systems. Consid-ering the large isotopic fractionation for sulfide-sulfate pairs atepithermal temperatures, the occurrence of barite in Gandi andQoleh-Kaftaran accounts for the isotopically light sulfides in thetwo deposits. In spite of the distinct variations in the host rocksand the ore minerals, no significant differences exist in the δ34Svalues for the four deposits. The δ34S values suggest a magmaticorigin for sulfur, and emphasize the role of magmatic fluids in theformation of epithermal systems.

APPLICATION OF SINGULAR VALUEDECOMPOSITION TO ESTIMATING GRAIN SIZESFOR CRYSTAL SIZE DISTRIBUTION ANALYSIS

Amenta, R.V., Amentarv@jmu.edu, Wilhelm, B., James MadisonUniversity, Harrisonburg, VA 22840

We explored the application of singular value decomposition(SVD) for the direct measurement of 3 dimensional grain sizes forcrystal size distribution (CSD) analysis. To test and verify results,we used data sets of irregular grain shapes taken from simulatedmicrostructures in which each grain is represented as a clusters ofpoints (unit cells). The microstructures were generated fromgrowths of prisms (1:1:5), plates (1:5:5), and cuboids (1:3:5), re-spectively, using governing equations for nucleation rate (N=e(at))and growth rate (G=ΔL/Δt). The prisms, plates and cuboids be-came irregular grains because of competition for growth space inthe microstructure. We used the ellipsoid algorithm of Moshtag(2006) which employs SVD to find the three semi-axes (radii) foran ellipsoid that approximates each cluster of grain points. How-ever, the size and shape of the ellipsoid depends upon a subjectiveparameter (error term) that controls the number of points to becontained within the ellipsoid. The crux of the problem then dealtwith avoiding “eye ball” subjectivity in selecting the best ellipsoidfor each grain. CSDs from various size ellipsoids (error terms)were compared to CSDs predicted by the governing equations,and the best results were obtained from ellipsoids that were com-pletely inscribed within the grains. Although such ellipsoids ap-peared smaller than their grains, they had one diameter that

yielded CSD slopes that compared favorably with the predictedCSD slopes for the grains. For grains derived from prisms the el-lipsoid long diameters yielded a CSD slope of -0.16 comparedwith the predicted of -0.17, for grains derived from plates the el-lipsoid intermediate diameters yielded a CSD slope of -0.29 com-pared to the predicted -0.28, and for grains derived from cuboidsthe ellipsoid intermediate diameters yielded a CSD slope of -0.32compared to the predicted -0.33. These results need to be con-firmed with other datasets, but results suggest that a specific di-ameter, that is dependent on the crystal shape, may be a goodindicator of grain size. Work is in progress on finding a numericalmethod for selecting the key diameters independent of knowledgeof crystal shapes. We anticipate that real application of this methodwill follow advances in grain resolution using high energy X-raytomography.

MICROBIAL Fe-REDUCTION IN MINE WASTEENVIRONMENTS

Amores, D.R., amoresr@mcmaster.ca, Norlund, K.L.I. and Warren,L.A., School of Geography and Earth Sciences, McMaster University,1280 Main St. W., Hamilton, ON L8S 4K1

Microbial reduction of iron oxyhydroxides (FeOOH) is a signifi-cant biogeochemical process linked to a myriad of critical envi-ronmental consequences: from the cycling of inorganic elements,to the transformation and remineralization of organic compoundsin both natural and engineered systems. Given that FeOOH areimportant sorbents for metals in the geomedia, microbially medi-ated reductive dissolution of Fe-oxyhydroxides can have a pro-found impact on the mobility of metal contaminants. Mine wasteenvironments are ideal sites for the activities of Iron ReducingBacteria (IRB) as current mining practices produce significantwaste residues rich in associated metals, solid-phase FeOOH andorganic matter. Our combined field and laboratory investigationswithin a mine waste environment showed a progressive dissolu-tion of amorphous FeOOH linked to IRB metabolism, with con-comitant release of metals held within these FeOOH mineralphases. Moreover, laboratory experiments assessing IRB-con-trolled FeOOH dissolution showed that cold temperature (~4°C)is the key control on this processes, promoting Fe(III)-respirationdriven apparently by cold-adapted microorganisms. Water chem-istry, substrate mineralogy, culture-dependent and independenttechniques of mine residue microcosms under controlled labora-tory conditions were used collectively to track FeOOH reduction,and identify the likely key microbial players driving this process.These results and their implications for mine waste environmentmetal dynamics will be discussed.

Au-As-Cu-Sb ORE-FORMING SYSTEM IN THEBAOGUTU GOLD DEPOSIT, WEST JUNGGAR (NORTHXINJIANG, NW CHINA)

An, F., Zhu, Y.F., School of Earth and Space Sciences, PekingUniversity, Beijing 100871, China

The Sb-bearing minerals, usually coexisting with native gold, arecommon in Sb-Au or Au-Sb hydrothermal deposit. Most of theAu-Sb hydrothermal deposits are mesothermal or epithermal,hosted in black shale or in limestone, as these rocks could con-tribute enough sulfur [1, 2]. Relatively alkaline and slightly re-ducing hydrothermal conditions provided by limestone favortransportation of Au and Sb are essential for the formation of Au-Sb deposits, while decrease of pH is the major controlling factorfor co-precipitation of stibnite and native gold [3]. Sulfur activitymight play an important role in the co-precipitation of native goldand antimony minerals (stibnite, berthierite) in the intrusion-re-lated gold system. Native antimony generally coexists with nativegold or aurostibite in gold deposit [4]. It is scarce to find native

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antimony coexisting with stibnite, because their stable fields areseparated by berthierite field. Here we describe antimony minerals(stibnite, ullmannite, native antimony, tetraedrite), coexisiting withnative gold, found in the Baogutu hydrothermal gold deposit (westJunggar, NW China).

The west Junggar is an important constituent of the centralAsian metallogenic region [5, 6, 7], which is characterized withoccurrence of several ophiolite belts, contacting with the LowerCarboniferous volcanic-sedimentary strata (LCVS) via faults. TheLCVS is mainly composed of coarse tuff sandstone with alternat-ing layers of tuff, tuff siltstone with basalt and siliceous locally.Post-collisional granitic plutons with ages of 295-310 Ma [8] in-truded into the LCVS.

One medium-sized copper deposit formed in the porphyrybody. Molybdenite separated from this porphyry copper depositwas dated to be 310 Ma by Re-Os method [9]. The Baogutu goldmine, occurring 15km SW from the porphyry copper deposit, is atypical hydrothermal gold deposit hosted in the LCVS. The tuffand tuff siltstone are the wall-rocks of most gold-bearing quartz-sulfide veins. Most of the gold-bearing quartz-sulfide veins arelensoid or ribbon-like. Some veins reach 400 m in depth withlength of 10 m to 150 m. More than twenty gold-bearing veinsare exposed on the surface, while the buried lodges are the majorore-bodies mined presently.

The ore-forming process of the Baogutu gold deposit can bedivided into three paragenetic stages based on the cross-cuttingrelationships and mineral assemblages. Gold-bearing fine-grainedquartz-sulfide veins, formed at stage II, cross-cut the coarse-grained quartz-sulfide veins formed at stage I. Native antimony-bearing calcite veins, formed at stage III, always cut through themineral assemblages formed at stages I and II. The stage II is themajor period for gold deposition. The native gold crystallized instage II is the major Au-bearing mineral. Native antimony in theBaogutu gold deposit, coexisting with calcite, stibnite and ullman-nite, formed only in stage III. It contains 96-97% Sb, 2.0-2.5% As,and trace contents of S, Fe, Cu, Pb, Au and Ni.

STIBIOCLAUDETITE (AsSbO3) IN THE GREENBUSHESPEGMATITE, WESTERN AUSTRALIA

Anderson, A.J., St. Francis Xavier University, Antigonish, NS B2G 2W5Stibioclaudetite, a new mineral discovered at the Tsumeb mine,Nambia, is here documented in polyphase inclusions within spo-dumene from the lithium zone of the Greenbushes mine, WesternAustralia. Stibioclaudeite and associated arsenic- and antimony-bearing phases were identified using of Raman spectroscopy, op-tical microscopy, and by selective focused ion beam (FIB) millingand SEM energy-dispersive x-ray analysis. Stibioclaudetite oc-curs sporadically in spodumene-hosted inclusions as small (typi-cally >6 µm) crystals, with or without quartz, zabuyelite andcookeite. Other arsenic- and antimony-bearing daughter mineralsin spodumene- and tourmaline-hosted inclusions include arseno-lite (As2O3), claudetite (As2O3), native arsenic, senarmontite(Sb2O3), and rare stibnite (Sb2S3), schneiderhohnite(Fe2+Fe3+3S5O13), getchellite (AsSbS3) and pääkkönenite(Sb2AsS2). Native arsenic also occurs as discrete solid inclusionsin spodumene.

Stibioclaudetite-bearing polyphase inclusions represent theproducts of a trapped carbonate-rich magmatic fluid that exsolvedfrom the pegmatite-forming melt during crystallization. The bulkcomposition of individual inclusions was modified by back reac-tions with the host mineral and by protracted necking during andafter daughter mineral precipitation. The occurrence of native ar-senic, arsenolite and senarmontite, and scarcity of arsenic and an-timony sulfides in the polyphase inclusions, indicates extremely

high activities of arsenic and antimony species, low ƒS2, andhighly reducing conditions.

PETROLOGY AND GEOCHEMISTRY OF THE MOOSEII LITHIUM-TANTALUM PEGMATITE DEPOSIT, NWT

Anderson, M.O., Lentz, D., Dept of Geology, University of NewBrunswick, Fredericton, NB E3B 5A3, M5r5u@unb.ca, and Falck, H.,Northwest Territories Geoscience Office, Yellowknife, NT

The Moose II rare-metal granitic pegmatite is located approxi-mately 115 km east-southeast of Yellowknife, NWT, along thenorth shore of the Hearne Channel of Great Slave Lake. It is anorth-trending dyke, approximately 430 m long and up to 61 mwide, dipping moderately to the west, discordantly hosted withinmetasedimentary rocks of the Archean Yellowknife Supergroup.This deposit is a historical producer of lithium and tantalum (1946– 1954).

This highly fractionated pegmatite is characterized by a nar-row (up to 8 cm wide), discontinuous border zone, a poorly de-fined fine-grained wall zone, several coarse-grained intermediatezones, and massive quartz and amblygonite-montebrasite corezones. The intermediate zones contain albite – quartz – muscovite– K-feldspar ± spodumene ± amblygonite-montebrasite. Themegacrystic spodumene (up to 1 m in length) forms normal to thewallrock contact in the outer zones of the pegmatite. Columbite-tantalite crystals, up to 2 cm in length, are found in many zonesof the pegmatite, and are intimately associated with saccharoidalalbitic zones and muscovite-rich greisen zones as platey or radi-ating needle-like crystals. Accessory phases include: petalite, ap-atite, graphite, cassiterite, lithiophillite, tourmaline, beryl, andlazulite. Detailed field mapping characterized the complex min-eralogical zonation of this dyke, reflecting the different distribu-tion and disposition of rock-forming and accessory minerals.

The whole-rock geochemical results of 56 channel, chip, andbulk samples indicate that the pegmatite is peraluminous (A/CNKranges from 1.0 to 1.6), sodium-rich, with a very low concentra-tion of Fe, Ca, Mg, Ti, and Mn, and elevated concentration of Ta,Nb, Rb, and Cs. The average Na2O/K2O is 2.8; the sodium en-richment is attributed to the abundance of cleavelandite (albite)throughout the dyke, and to the presence of discreet units of sac-charoidal albite. Throughout the pegmatite, the concentration ofTa ranges from 3 to 770 ppm (averaging 110 ppm), and Nb rangesfrom 3 to 1520 ppm (averaging 127 ppm), with the highest valuesof Ta and Nb found within the secondary greisen zones. Lithiumconcentration reaches a maximum of 2.731 wt.% Li2O, averaging0.436 wt.% Li2O. Calculation of monazite and zircon saturationtemperatures is consistent with crystallization below 600°C. Thewhole-rock geochemistry has allowed the classification of theMoose II pegmatite as a spodumene-subtype of the complex fam-ily of rare-element LCT-type pegmatites.

INSIGHTS INTO UNDERSTANDING THE CARBON-URANIUM (± SULFUR AND BORON) GEOCHEMICALSYSTEM ALONG A RETROGRADE P-T-T PATH FROM600°C TO 250°C: NEW CONSTRAINTS WITHIMPLICATIONS FOR U/C-TYPE URANIUM DEPOSITS

Annesley, I.R., jnrivine@sasktel.net, JNR Resources Inc., 204-31522nd St. East, Saskatoon, SK S7K 0G6, and Wheatley, K., ForumUranium Corp., #910-475 Howe Street, Vancouver, BC V6C 2B3

Unconformity-type (U/C-type) uranium deposits of the ca. 1.75Ga Athabasca Basin are the world’s highest-grade uranium de-posits. Most of these deposits have common characteristics thatresearchers attribute their genesis to some variation of the diage-netic-hydrothermal model, which invokes the mixing of highlysaline, oxidized, basinal brines with variably reduced basementfluids between 150 to 220°C. However, unresolved issues still existin the understanding of the uranium source, the flow paths of the

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mineralizing fluids, the nature of the reductant, and the role ofgraphite and carbonaceous matter in the genesis of these deposits.

In the Athabasca Basin, many of the U/C-type uranium de-posits are rooted within/near reactivated high-strain zones hostedby graphitic pelitic gneisses and graphitic/carbonaceous fault zonerocks. Many types, habits, and generations of graphite and spa-tially associated carbonaceous matter are found in these high-strain zones. Researchers noted the presence of carbonaceousmatter and solid bitumen within the alteration and ore zones ofthese deposits, leading to the hypothesis that the destruction ofgraphite and the formation of hydrocarbons, such as methane,were the main reducing agent in their genesis. Other researchershave argued on the basis of isotopic constraints and geochemicalmodeling that this hypothesis should be rejected and graphite isnon-reactive in this 150 to 220°C range, and have appealed toother potential reducing agents. However, all of the larger, high-grade deposits in the Athabasca Basin are spatially associated withgraphitic lithologies, and within many of these, we have identifiedgraphite alteration. Moreover, recent research indicates that thecarbonaceous matter (i.e. CM buttons) records “a complex fluid-geochemical-uranium remobilization history”.

The purpose of this paper is to provide new insights into ourunderstanding of the carbon-uranium (± sulfur and boron) geo-chemical system. Results from field, petrography, geochemistry,Raman spectroscopy, and synchrotron X-ray studies of graphiticpelitic gneisses and graphitic/carbonaceous fault zone rocks arepresented and interpreted in light of recently published thermody-namic calculations of a cooling C-O-H fluid-graphite system. It isobserved that graphite/carbon is consumed or precipitated alongthe retrograde P-T-t path of basement lithologies from 600 to250°C. We also note that there are significant differences for car-bon precipitation and/or accumulation within closed versus openfluid system conditions. The authors have also considered a min-eralogically and chemically evolving unconformity breached byC-U-bearing reactivated faults. Finally, these constraints on thedifferent carbon forms/states (graphite, CM, and methane) haveimplications for reducing uranyl sulfate solutions and precipitatinguraninite.

MINERAL EXPLORATION LEARNING EXPERIENCEAT THE UNIVERSITY OF SASKATCHEWAN: WHY,HOW, AND OUTCOMES

Ansdell, K.M., Department of Geological Sciences, University ofSaskatchewan, 114 Science Place, Saskatoon, SK S7N 5E2,kevin.ansdell@usask.ca

As part of the Geology program at the University ofSaskatchewan, undergraduate students can take a one semestercourse in Mineral Deposits. The focus of the course is to providean overview of models for magmatic and hydrothermal mineraldeposits, but there is limited time to consider in detail the appli-cability of these models for exploration. In 2003, a new term proj-ect, an “exploration game”, was initiated to allow undergraduatestudents to use what they learn in the lecture component of thecourse to develop an exploration strategy for a particular commod-ity. The aim was to allow the students to consider all aspects ofthe “real life” exploration industry.

The teams consist of up to five students, and the commoditiesthat have been targeted have been uranium, gold, diamonds,nickel, PGE, REE, chromium, VMS copper-zinc, porphyry cop-per, Li-Be pegmatites, and iron. They are provided with a smallbudget of $1M, which they must use to develop a one-year explo-ration program for their commodity. They must use their under-standing of mineral deposit types to target a suitable unstaked area.Given the budget most teams have concentrated on regions withinCanada, although teams have also chosen target areas in Australia,

Argentina, and Iran. For each commodity, they must consider theappropriate techniques they would employ to identify potentialmineralization and alteration, such as field mapping, geophysics,geochemistry, and drilling. Regulatory, environmental, and com-munity relations issues must also be considered if necessary.

At the end of the semester, each team is required to presenttheir idea for a geological target and the rationale for their choice,the exploration techniques they would use, and an overview oftheir budget in a 20-minute powerpoint presentation. The presen-tation is given by one student, chosen by the team, while the otherteam members provide support during the following question pe-riod. The mineral exploration community in Saskatoon are invited,and each year up to 20 industry representatives attend varying inseniority and experience. The industry representatives subse-quently send comments on the presentations and target ideas toassist me in choosing the team that will receive the “virtual $1M”.The success of the project has led to an increase in the number ofstudents actively pursuing employment in the mineral explorationindustry, and this presentation will include comments from previ-ous team members and the industry community as well as anoverview of the target areas chosen over the years.

GEO-FOCUSED SITUATIONAL AWARENESS INROBOTIC PLANETARY MISSIONS: LESSONS FROMAN ANALOGUE MISSION AT MISTASTIN LAKEIMPACT STRUCTURE, LABRADOR, CANADA

Antonenko, I., iantonen@uwo.ca, Mader, M.M., Osinski, G.R., Battler,M., Beauchamp M., Cupelli, L., Chanou, A., Francis, R., Marion, C.,McCullough, E., Pickersgill, A., Preston, L., Shankar, B., Unrau, T.and Veillette, D., Centre for Planetary Science and Exploration,University of Western Ontario, London, ON & Canadian LunarResearch Network

Planetary exploration relies on robotic missions. However, remotedata provides different information than the immersion that fieldgeologists experience on site. We observed geo-focused issues ofreduced situational awareness during a Canadian Space Agency-funded analogue mission at Mistastin Lake impact structure,Labrador, Canada. A field team collected data under the directionof a remote mission control team (2,000 km away), who had nevervisited the field site.

Mission control encountered difficulties related to scale, re-lief, and geological detail, which the field team did not. Interpret-ing scale in images proved difficult, even with measurement data(numbers don’t carry the same impact as that experienced in thefield). Relief was difficult to intuit from available data, even withstereo images. Finally, mission control missed several geologicallyinteresting details the field team identified on their first day’s walkaround. Together, these affected mission control’s ability to inter-pret geology.

Most of these issues are also related to time constraint prob-lems. Time was required to upload data. Remote data interpretationis less intuitive, so took longer. Subsequent data collection had tobe discussed, prioritized, and re-quested. Resolution improve-ments required repetition of this time-consuming cycle. Miscom-munication, between mission control and the field, resulted inwasted cycles. In contrast, the field team absorbed and processedvisual information intuitively (modifying distance, view angle, etc.to improve observations), made group or unilateral decisionsquickly, and followed up on those instantly. As a result, the fieldteam observed and interpreted more geology than mission control.

Several techniques may be helpful in mitigating these situa-tional awareness issues. Extensive training programs, to instill anintrinsic sense of scale from numerical values, could be developedand employed. Stereo camera data collected from various anglescould improve fidelity. Finally, the different timelines of robotic

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missions need to be recognized and embraced. Robots take longerthan humans to complete tasks, but robotic missions last monthsor years (not days/weeks). Analogue missions need to incorporatethis aspect into their testing methodologies.

REVISED BEDROCK GEOLOGY OF THE SOUTHERNANTIGONISH HIGHLANDS, NOVA SCOTIA, CANADA

Archibald, D.B.1, 103795a@acadiau.ca, White, C.E.2, Barr, S.M.1,Murphy, J.B.3, Hamilton, M.A.4 and Escarraga, E.A.1, 1Department ofEarth and Environmental Science, Acadia University, Wolfville, NSB4P 2R6; 2Nova Scotia Department of Natural Resources, PO Box698, Halifax, NS B3J 2T9; 3Department of Geology, St. Francis XavierUniversity, Antigonish, NS B2G 2W5; 4University of Toronto, JackSatterly Geochronology Lab, Toronto, ON M5S 3B1

Detailed (1:10 000-scale) bedrock mapping of the southernAntigonish Highlands in Avalonian northeastern mainland NovaScotia, combined with U-Pb geochronology and petrological stud-ies, have resulted in major changes to previously inferred geolog-ical relationships in the area. The most extensive unit, the KeppochFormation, forms the core of the southern highlands and consistsof rhyolitic to dacitic flows and tuffs with minor andesitic tuff andcherty siltstone. It grades upward into laminated cherty siltstoneto wacke with minor rhyolitic to basaltic tuff of the James RiverFormation which outcrops along the northern and southern flanksof the highlands. The Chisholm Brook Formation consists domi-nantly of basaltic flows and tuff with rare rhyolitic tuff and flows,and laminated cherty siltstone. These three units have been in-truded by probably coeval ca. 618-603 Ma calc-alkaline, “I-type”,dioritic to syenogranitic plutons. Of less certain age is the uncon-formably overlying Bears Brook Formation which consists of redarkosic sandstone to conglomerate with minor basaltic to rhyolitictuff and flows, and rare laminated cherty siltstone.

The West Barneys River plutonic suite is a previously unrec-ognized assemblage of medium- to coarse-grained syenite to al-kali-feldspar granite and gabbro which outcrops over an area ofabout 100 km2 in the central part of the map area. A syenite sampleyielded a middle Ordovician U-Pb (zircon) age of 469.4 ± 0.5 Ma.Magma mixing and mingling textures indicate a co-genetic rela-tionship between the felsic and mafic lithologies. The intermediateto felsic rocks are in part peralkaline and have characteristics ofA-type granitoid suites. Preliminary data indicate that the gabbroicrocks have compositions characteristic of continental within-platetholeiite. The plutonic suite and its host rocks are intruded by nu-merous mafic and felsic dykes and sills, indicating on-going ex-tension after pluton emplacement. The structural evidencecombined with the overall distribution of these older units suggeststhe southern Antigonish Highlands form a broad east-west domalfeature with the Ordovician plutonic suite forming the core.

Unconformably overlying the older units is quartz-rich, lo-cally fossiliferous sandstone to granule conglomerate and rarelimestone that is tentatively assigned to the Early Silurian BeechillCove Formation, the basal unit of the Arisaig Group. This unit isconformably overlain by grey to black fossiliferous wacke, silt-stone, and slate assigned to the Ross Brook Formation. Unlike theolder units, the units of the Arisaig Group have not been intrudedby mafic or felsic sills and dykes.

DISTRIBUTION AND MOBILITY OF TOTALPETROLEUM HYDROCARBONS IN SOILS: CASESTUDY OF THE SOUTH PARS GAS COMPLEX,NORTHERN PERSIAN GULF

Ardestani, M., Akbari, A., Ghazban, F., University of Tehran,Environmental Engineering Dept.,Faculty of Environment, Tehran,Iran, ardestan@ut.ac.ir

Hydrocarbon contamination has been recognized as one of themost serious environmental threats arising from the exploration,

refining and transport of oil and gas resources. In terrestrial envi-ronments, the quality of soil, in terms of biological or physical andchemical properties, would be altered as a result of hydrocarboncontamination. This work discusses the distribution of total petro-leum hydrocarbons (TPH) contamination in soil within areas ofthe South Pars Gas Complex (S.P.G.C.), located on the northernshore of the Persian Gulf. To assess the potential risk to ground-water, in situ contaminant mobility was examined in vertical soilprofiles. Two series of soil sampling were conducted at 40 and 15points, respectively. TPH was determined in accordance with stan-dard methods of TPH analysis. The maximum detected concen-tration was 1300 +80.36 mg/kg, originating from a leakingunderground waste line. Significant levels of TPH were also de-tected at solid waste stabilization and disposal sites, a liquid wastestorage area, fire training area and in the vicinity of the oil sepa-ration unit (API). Groundwater sampling followed by total organiccarbon (TOC) analysis was also performed. Although the ground-water samples did not show any evidence of contamination, ver-tical contamination profiles clearly demonstrated that thegroundwater contamination is possible to occur in the near future,if no remedial measure is taken immediately. Since the refinerieshave been brought to production for the last 5 years, it is necessityto monitor the increasing industrial activities in the area. There-fore, the regulation should address cleanup standards and the pre-ventive and remedial guidelines for petroleum hydrocarboncontamination in soil and/or groundwater.

WHERE IS THE MAGNETIC CRUST OF MARS?Arkani-Hamed, J., Physics, University of Toronto, Toronto, ON M5S1A7, and Boutin, D., Earth and Planetary Sciences, McGill University,Montreal, QC H3A 2A7

The strong magnetic anomalies over the southern hemisphere ofMars have been interpreted in terms of strong magnetization ofMartian crust. Estimates of depth to Curie temperature of viablemagnetic mineral at about 4 Ga imply that the potentially magneticlayer must have been in the upper 70 km of the crust, and that thelower ~10 km must have been effectively demagnetized by vis-cous decay. The observation that the floors of the giant impactbasins Hellas, Isidis and Argyre are non-magnetic has been relatedto impact demagnetization of the pre-exiting magnetized crust.The rock magnetic measurements show appreciable demagnetiza-tion at pressures higher than 3 GPa. Accordingly, an impact pro-ducing a crater of diameter larger than 200 km is expected todemagnetize almost the entire magnetic crust and create a mag-netic anomaly observable at satellite altitudes. Besides the north-ern lowland which is likely demagnetized by the giant Borealisimpact, and the Tharsis bulge which is formed after the cessationof the core dynamo of Mars, an extensive ancient area in the south-ern hemisphere, south of 30S, extending from west of Hellas toeast of Argyre show no appreciable magnetic anomalies associatedwith craters. We investigate all of the craters and some of theQuasi Circular Depressions (QCD) larger than 200 km in diameterover this area. Using high resolution MOLA topography and themost recent JPL gravity model (jgmro-1102b), we determine theundulations of Moho and the thickness of the crust beneath eachof the craters and QCDs. The majority of the craters and some ofQCDs have distinct mantle plugs directly beneath, suggesting thatimpacts have effectively disturbed the crust. We extracted the ver-tical component of the magnetic field over these craters and QCDsfrom Mars Global Surveyor magnetic data at 400 km altitude, andused covariance analysis to derive the most reliable magneticanomalies. We also extracted the Electron Reflectometer magneticdata at 185 km altitude over these features. However, none of thesefeatures show magnetic anomaly at satellite altitudes, emphasizingthat the ancient crust in this vast area has not been appreciably

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magnetized by the core dynamo prior to the impacts. Also, detailedinvestigation of the magnetic anomalies surrounding Hellas, Isidisand Argyre basins reveals that the surrounding crust actually isnot continuously magnetized. The magnetic anomalies are asso-ciated with localized magnetic source bodies. This seems to be thecase elsewhere, except in Cimmeria and Sirenum regions, imply-ing that Martian crust as a whole may not be continuously mag-netic and magnetic anomalies are due to localized magneticbodies.

GIANT IMPACTS CRIPPLE CORE DYNAMOS OFSMALL TERRESTRIAL PLANETS

Arkani-Hamed, J., University of Toronto, Toronto, ON M5S 1A7,jafar@physics.utoronto.ca

Large impacts not only create giant basins on terrestrial planetsbut also heat their interior by shock waves. We investigate the im-pacts that have created the largest basins existing on the planets:Utopia on Mars, Caloris on Mercury, Aitken on Moon, all formedat ca. 4 Ga. We determine the impact-induced temperature in-creases in the interior of a planet using the “foundering” shockheating model of Watters et al. (2009). The post-impact thermalevolution of the planet is investigated using 2D axi-symmetricconvection in a spherical shell of temperature-dependent viscosityand thermal conductivity, and pressure-dependent thermal expan-sion. The impact heating creates a superheated giant plume in theupper mantle which ascends rapidly and develops a strong con-vection in the mantle of the sub-impact hemisphere. The upwellingof the plume rapidly sweeps up the impact heated base of the man-tle away from the core-mantle boundary and replaces it with thecolder surrounding material, thus reducing the effects of the im-pact-heated base of the mantle on the heat flux out of core. How-ever, direct shock heating of the core stratifies the core, suppressesthe pre-existing thermal convection, and cripples a pre-existingthermally-driven core dynamo. It takes about 17, 4, and 5 Myr forthe stratified cores of Mars, Mercury, and Moon to exhaust impactheat and resume global convection, possibly regenerating core dy-namos.

LATERALLY ACCRETING, DEEP-MARINE SINUOUSCHANNELS — INITIATION, DEPOSITION ANDTERMINATION

Arnott, R.W.C., University of Ottawa, Ottawa, ON K1N 6N5,warnott@uottawa.ca

Deep-marine sedimentary rocks of the Neoproterozoic Winder-mere Supergroup are superbly exposed at the Castle Creek studyarea in east-central B.C. Here channel complex 2 exposes a net-work of vertically-stacked and laterally-offset, sharp-based deep-marine, sinuous channel fills. Channels are sharply bounded ontheir outer bend side by an erosion surface that separates coarse-grained channel fill strata from (older) fine-grained levee depositsin which sandstone injections are common. The inner bend, or“point bar” side of the channel consists of well developed channellateral accretion deposits, or LADs, that are inclined up to 7-12°toward the channel base. Grain size changes little obliquely-up-ward along an individual LAD, or vertically upward through thechannel fill. LADs consist of two repeating and interstratifiedkinds: coarse-grained LADs consisting of strata up to granule con-glomerate, and fine-grained LADs composed of thin- to medium-bedded finer-grained turbidites. The rhythmic intercalation ofcoarse- and fine-grained LADs is interpreted to be related toepisodic changes in the nature of sediment transport and deposi-tion within the local channel bend. This history of alternatingcoarse and fine-grained sedimentation was repeated several timesin the channel bend as it migrated laterally. Commonly, lateralchannel migration was terminated abruptly in one of two ways:

incision by a younger sinuous channel, or detachment related togravitational sliding. In at least one example, incision is made ev-ident by an extensive mudstone-clast breccia zone separating thechannel fills. Clasts were likely sourced from fine-grained depositsthat had accumulated in the older channel fill following channeldeactivation. Erosion associated with rejuvenation of the channelfairway formed the breccia horizon, which then is overlain byLADs of the younger channel fill. Channel fills truncated by slidedetachment are characterized by sharp surfaces that tend to cutobliquely downward and across the mudstone-rich upper part ofthe LADs and then sole-out in the lower amalgamated sandstonepart at the base of the channel fill. Gravitational instability wasmost likely enhanced by the steep angle of the lateral accretionsurfaces, the intercalation of sediment of contrasting mechanicalstrength, and possibly also the reduction of transport activitywithin the channel. Collectively, the lithological characteristics ofsinuous channel fills and the recognized styles of channel termi-nation may provide help in understanding some puzzling seismicattributes from deep-marine sinuous channel systems.

ORE CHARACTERISTICS AND GENESIS IN CHAHMOSA DEPOSIT, TORUD-CHAHSHIRIN RANGE,NORTH-CENTRAL IRAN

Ashrafpour, E., Ministry of Sciences, Researches, and Technologies,Tehran, Iran, Haghighi, E. and Alirezaei, S., Faculty of Earth Sciences,Shahid Beheshti University, TehranThe Chah Mosa is located in Torud-Chahshirin Range in

~120 km south of Shahrood in Semnan province. The TertiaryTorud-Chahshirin Magmatic Range (TCMR) in north Central Iran,hosts several base and precious metal deposits. The Chah Mosacopper deposit in central part of TCMR occurs as quartz-chal-cocite veins and veinlets in a porphyritic quartz-monzodiorite andincludes: Two major types of veins are distinguished: a) Chal-cocite-bearing milky quartz veins, with distinct comb textures, 1-5 cm thick and 1-100 metre long; b) Chalcocite-bearing greyquartz veinlets,

THE GEOLOGICAL SETTING, COMPOSITION, ANDORIGIN OF THE FRASER LAKES ZONE B GRANITICPEGMATITE-HOSTED U-Th-REE MINERALIZATION,WOLLASTON DOMAIN, NORTHERNSASKATCHEWAN, CANADA

Austman, C.L.1, christine.austman@usask.ca, Ansdell, K.M.1 andAnnesley, I.R.1,2, 1Department of Geological Sciences, University ofSaskatchewan, 114 Science Place, Saskatoon, SK S7N 5E2; 2JNRResources Inc, 315-22nd Street East, Suite #204, Saskatoon, SK S7K0G6

The Fraser Lakes granitic pegmatite-hosted U-Th-REE mineral-ization is located in the Wollaston Domain of northernSaskatchewan, about 25 km from the southeastern edge of theAthabasca Basin. The pegmatites intrude the highly deformed, un-conformable contact between Paleoproterozoic Wollaston Groupmetasedimentary gneisses and underlying Archean orthogneisses.Zone B pegmatites are concentrated within a NNE-plunging an-tiformal fold nose, and are sub-parallel to the dominant gneissosityin the host rocks, evidence for a strong structural/metamorphiccontrol on their location.

Zone B radioactive pegmatites can be separated into twogroups based on their U and Th contents, Th/U ratios, and locationwithin the fold nose. Those in the western part of the fold are Uand Th-enriched (Th/U ~1; with up to 2460 ppm U and 1100 Th),while those in the eastern part are Th+LREE-enriched with up to7310 ppm Th, 700 ppm U (and Th/U typically >5), 4410 ppm La,9050 ppm Ce, and 3590 ppm Nd. The main U-Th-REE mineralsin the uraniferous pegmatites include uraninite, uranothorite, zir-con, and allanite, while those in the thorium- and LREE-enrichedpegmatites include monazite, uranothorite-thorite, and zircon withrare allanite.

The Th- and LREE-enriched pegmatites tend to be more sim-ilar in composition to the pelitic gneisses than the uraniferous peg-matites. The uraniferous pegmatites contain more SiO2 and lessTiO2 than the Th- and LREE-enriched pegmatites, and likely rep-resent more highly evolved/fractionated melts. Both groups ofgranitic pegmatites show strong linear trends away from peliticgneiss compositions on major element Harker diagrams; indicat-ing a possible compositional relationship between the pegmatitesand pelitic gneisses.

The strongly peraluminous to weakly metaluminous characterof the pegmatites suggests that they formed by partial melting ofa metasedimentary source. Since the pegmatites do not show a di-rect connection to migmatitic leucosomes in the pelitic gneiss hostrocks, it is likely that the melt required for them to form was gen-erated at depth. The melts would have travelled up thestructural/lithological discontinuity between the Archean or-thogneisses and Wollaston Group metasedimentary rocks to thelevel of emplacement, where they crystallized to form pegmatitebodies. During transport, the melts would have undergone assim-ilation-fractional crystallization processes, causing enrichment ofthe granitic pegmatites in incompatible elements (especially U,Th, and REEs).

The origin of the Fraser Lakes granitic pegmatites is similarto that for other granitic pegmatite/leucogranite-hosted uraniumdeposits, including the alaskite-hosted deposits at Rossing(Namibia), and the numerous uraniferous granitic pegmatite oc-currences in the Grenville Province.

FORAMINIFERAL DISTRIBUTION IN THE SEYMOURBELIZE INLET COMPLEX, BRITISH COLUMBIA:IMPLICATIONS FOR HOLOCENEPALEOCEANOGRAPHIC RECONSTRUCTION

Babalola, L.O., Center for Petroleum & Minerals, KFUPM, Dhahran31261, Saudi Arabia, Patterson, R.T., Prokoph, A., Earth SciencesDepartment & Ottawa-Carleton Geoscience Center, Ottawa, ON K1S5B6, and Roe, H., School of Geography, Archaeology andPalaeoecology, Queen’s University Belfast, Belfast BT7 1NN, UK

The Holocene distribution of agglutinated foraminifera and fresh-water thecamoebians was reconstructed from two piston cores col-lected from glacier-carved Frederick and Alison sounds in theSeymour-Belize Inlet Complex (SBIC), British Columbia coast.The sedimentary record archived in these late Holocene cores wascharacterized by unevenly distributed massive and laminated in-tervals interrupted by occasional slumps and turbidites.

In the Frederick Sound core, the faunal assemblages are over-whelmingly dominated by the foraminiferal species Eggerella ad-vena. In the Alison Sound core, thecamoebians as a group aremore abundant than any individual foraminiferal species. Clusteranalysis identified the presence of four foraminiferal/thecamoe-bian biofacies; Eggerella advena Biofacies, Eggerella advena-Re-curvoides turbinatus-Spiroplectammina biformis Biofacies,Thecamoebian spp. Biofacies and the Eggerella-advena-The-camoebian spp. Biofacies. In both cores, these biofacies are char-acterized by a low Shannon Diversity Index (SDI) (0.064-1.55)indicating that the foraminifera lived in an unfavourable habitat.The predominance of low-oxygen tolerant agglutinatedforaminifera and absence of calcareous fauna indicate that oxygenwas the main environmental stresser, which exhibited considerablecontrol on the late Holocene foraminiferal distribution in theSBIC. Abundant organic matter in the core sediments provide ad-ditional evidence of the low oxygen conditions that precludedmost organisms that might have utilized this rich food resource.The presence of varying proportions of freshwater thecamoebiansthroughout the cores is a result of soil erosion from the adjacentnearby shore in these narrow fjords and subsequent reworking ofthe nearshore sediments into deep water.

A moderate upcore increase in the abundances of theglaciomarine indicator species Spiroplectammina biformis, Re-curvoides turbinatus, Portatrochammina bipolaris and Cribrosto-moides jeffreysii within the Eggerella advena-Recurvoidesturbinatus-Spiroplectammina biformis Biofacies and Eggerella-advena-Thecamoebian spp. Biofacies suggests a subtle shift tocooler bottom water conditions in the late Holocene. Developmentof these relatively cold bottom water conditions seems to havebeen coeval throughout the SBIC becoming established at ~2,860cal yr BP in both the Frederick Sound and Alison Sound cores,

A 1200-YEAR RECORD OF PALEOCEAONGRAPHICAND PALEOCLIMATIC VARIABILITY FROM THESEYMOUR-BELIZE INLET COMPLEX, CENTRALCOASTAL MOUNTAINS REGION OF BRITISHCOLUMBIA

Babalola, L.O.1, Patterson, R.T.2, Prokoph, A.2, Swindles, G.T.3 andKumar, A.1, 1Center for Petroleum & Minerals, KFUPM, Dhahran31261, Saudi Arabia; 2Earth Sciences and Ottawa-Carleton GeoscienceCenter, Carleton University, Ottawa, ON K1S 5B6; 3Division ofArchaeological, Geographical and Environmental Sciences (AGES),School of Life Sciences, University of Bradford, Bradford BD7 1DP,UK

Foraminiferal biofacies and trace elements distribution patternswere utilized to investigate variation in regional paleoceanographyand paleoclimate through the last ~1200 years, as archived in afreeze core (VEC0A13) from Mereworth Sound (MSFC) in theSeymour-Belize Inlet Complex (SBIC). Ocean circulation patterns

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in the SBIC are strongly linked to precipitation, which is closelylinked to the relative strength and position of the Center of Action(COA) of the Aleutian Low (AL) and North Pacific High. TheMSFC was comprised of monotonous massive mud and silt sedi-ments interspersed with minor sandy intervals. The fossiliferousupper portion (after ~1300 A.D. AD) was found to be sandier thanthe poorly fossiliferous lowermost section (~820-1300 AD). Adown core increase and higher concentrations of aluminosilicaterelated elements (e.g. Al, Ca, Ti, K and Mg) particularly prior to~1300 AD, are consistent with the predominance of mud sedi-ments in the basal portion of the core (~820-1300 AD).

Cluster analysis of the quantified foraminiferal results iden-tified four biofacies: Haplophragmoides bradyi-Eggerella advena-Stainforthia feylingi, Buccella frigida, Buccella frigida-Cribroelphidium excavatum, and Buccella frigida-Haplophrag-moides bradyi Biofacies, which characterized subtly different de-positional environments in sediments deposited after ~1300 A.D.It can be generally stated though that the dominance of marine cal-careous foraminifera indicate that higher oxygen and cooler tem-perature prevailed for a significant proportion of the coredeposited after ~1300 years A.D. The high concentrations of redoxsensitive elements and general absence of foraminifera in the basalportion of the core ~820-1300 AD suggests that deposition of thispart of the MSFC occurred under warm, low-oxygen bottom waterconditions. This basal core interval likely corresponds to the Me-dieval Warm Period (MWP). The reduced oxygen conditionslikely came about as a result of diminished precipitation in theSBIC catchment as the COA of the AL progressively moved west-ward over time, resulting in significantly reduced estuarine circu-lation and only infrequent incursions of oxygenated open waterinto the SBIC basin. The overlying fossiliferous ~1300-1500 ADinterval corresponds to the onset of the Little Ice Age (LIA). Dur-ing this time the COA of the AL migrated further to the East,which in the SBIC resulted in higher levels of precipitation, whichgreatly enhanced estuarine circulation and frequent incursions ofcold, well oxygenated ocean currents into the bottom waters anddevelopment of a diverse calcareous foraminiferal fauna.

THE FRACTIONATION OF Nb AND Ta: A POWERFULTRACER OF SILICATE DIFFERENTIATION

Babechuk, M.G., mbabechuk@gmail.com, and Kamber, B.S.,Department of Earth Sciences, Laurentian University, 935 RamseyLake Road, Sudbury, ON P3E 2C6, bkamber@laurentian.ca

Niobium (Nb) and tantalum (Ta) are both highly lithophile high-field-strength elements that occur in a pentavalent state with nearlyidentical effective ionic radii; thus, the two elements are tradition-ally regarded as geochemical twins and are not expected to frac-tionate significantly during magmatic processes. Two majorempirical observations, however, challenge this view. First, all ac-cessible Earth reservoirs are subchondritic. The currently proposedchondritic Nb/Ta ratio of 19.9±0.6 is significantly higher thanthose of continental rocks, mantle-derived basalts, and the sub-continental lithosphere. It has been proposed that the ‘missing’ Nbresides in the core, subducted eclogitic slabs in the deep mantle,or a combination of the two. Second, the degree of fractionationbetween Nb and Ta during silicate differentiation is much higherthan expected. There is agreement that fractionation of Nb and Tamost likely occurs somewhere in the subduction zone magma fac-tory, but there is currently no consensus on the process.

With respect to the first observation we report new high-pre-cision Nb and Ta data for a suite of chondritic meteorites, includ-ing Orgueil. The new data yield a very consistent Nb/Ta of21.55±0.27 for chondrites with smooth REE patterns. This findingreinforces the apparent Nb/Ta mass imbalance in the silicate Earth.Eoarchean metasedimentary and metabasaltic rocks have much

lower Nb/Ta (~14-16), which suggests that the missing Nb eithersits in the core or that the early terrestrial differentiation event ev-ident in 142Nd isotopes was also capable of strongly fractionatingNb from Ta, for example in a Ti phase.

With respect to the second observation, we report new datafor greenschist facies basalts from the 1.9 Ga Flin Flon Belt. Someof these have very high Nb/Th (up to 33) and Nb/Ta (up to 18.5)ratios that anti-correlate with LOI. This suggests that relative toNb, Th and Ta might be more soluble in metamorphic fluids. Dur-ing dehydration of oceanic slabs, Ta may be preferentially trans-ferred to the mantle wedge and that the generally low Nb/Ta ofcontinental arc magmas is an expression of this process.

The high-field-strength elements are widely considered asimmobile but high-precision data show that even pentavalentcations can be differentially mobilized in geological environments,leaving behind important chemical clues that are beginning to beunderstood.

A PERMEABILITY STUDY OF CRYSTAL-BEARINGSTROMBOLI BASALTIC MAGMAS: IMPLICATIONSFOR STROMBOLI ERUPTIONS

Bai, L-P.1, liping.bai@mail.mcgill.ca, Baker, D.R.2,1, Polacci, M.2,3

and Hill, R.J.2,4, 1Earth and Planetary Sciences, McGill University,Montreal, QC H3A 2A7; 2Aurex Corporation; 3Istituto Nazionale diGeofisica e Vulcanologia, sezione di Pisa, Via della Faggiola, 32,56126 Pisa, Italy; 4Department of Chemical Engineering and McGillInstitute for Advanced Materials, McGill University, Montreal, QCH3A 2B2

In-situ bubble formation and growth in crystal-bearing Strombolibasaltic magmas were studied with X-ray microtomography athigh (1.85 micron voxel edge length) and low (5.46 or 7.81 micronvoxel edge length) resolution. The effects of crystals on bubblesizes and distributions were investigated and compared to previousexperimental studies of bubble size distributions in crystal-freesamples and to natural scoria from Stromboli. The permeabilitiesof vesicular crystal-bearing Stromboli basaltic run products weredetermined using lattice-Boltzmann simulations and laboratorymeasurements. The permeability and porosity are related by apower-law: k(Ф= 2.04 x 10-20Ф5.24 m2. Such permeabilities areapproximately 1 to 2 orders of magnitude higher than those incrystal-free Stromboli basaltic melts in the porosity range of 31.6to 55.3%. Crystal-bearing run products can easily form large bub-bles due to coalescence, and do not form foams consisting of mul-tiple, partially coalesced bubbles that are generally observed inaphyric samples. The larger bubbles in the crystal-bearing samplescontribute to the higher permeability values.

Our experiments show that the presence of crystals produceshigh bubble number densities in the degassing magma, and thatthe bubble number density in crystal-bearing samples can decreasesignificantly during short durations of bubble growth. We proposethat normal Stromboli explosions are driven by the high bubblenumber density of crystal-rich magma. The higher permeabilityin crystal-bearing samples implies highly efficient degassing inthe shallower, crystal-rich, Stromboli magma body that suppliesthe normal Strombolian activity and sustains passive degassing.This degassed, high density magma is known to sit above the crys-tal-poor, volatile-rich magma body that produces paroxysmaleruptions yielding low crystallinity pumice. We suggest that thisdegassed scoriaceous magma body acts as a cap that allows bub-bles to accumulate and form a foam layer at the top of the volatile-rich pumice magma body, potentially resulting in a more-violentparoxysmal explosion.

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GEOLOGICAL SETTING OF THE LALOR LAKE Zn-AND Au-RICH VMS DEPOSIT, SNOW LAKE,MANITOBA, CANADA

Bailes, A.H., Bailes Geoscience, 6 Park Grove Drive, Winnipeg, MBR2J 3L6, bailesgeoscience@mts.net, Gilmore, K., Levers, J. andJanser, B., Hudson Bay Exploration and Development CompanyLimited, Box 1500, Flin Flon, MB R8A 1N9

This presentation gives the results of an investigation of the geo-logical setting of the Hudson Bay Mining and Smelting CompanyLimited (HBMS) Lalor Lake deposit. The deposit setting is dis-cussed in terms of its stratigraphic position and relationship to alarge, well exposed, footwall alteration system. An important andsurprising outcome is identification of an angular discordance (60-45°) between strata in the hanging wall and underlying rocks thathost the Lalor Lake, Chisel Lake and North Chisel Zn-rich VMSdeposits. This angular discordance is interpreted to be a structuraldiscontinuity, most likely a pre-metamorphic thrust fault followingthe top of the deposits. The similar stratigraphic and structural set-ting of the nearby Chisel and Chisel North mines strongly suggeststhat all three deposits are part of the same, large-scale VMS systemand share the same hangingwall thrust fault. In contrast, thenearby, more Cu-rich Photo Lake deposit is part of the structuralhanging wall (thrust sheet) above the Lalor deposit. This investi-gation of the Lalor Lake deposit has dramatically modified previ-ous understanding of the regional geology and interpreted settingof the Snow Lake VMS deposits.

3-D IMAGING OF GEOMATERIALS: X-RAYMICROTOMOGRAPHY APPLIED TO VOLCANICEJECTA

Baker, D.R.1, don.baker@mcgill.ca, Polacci, M.2, Bai, L.1, Mancini,L.3, LaRue, A.1 and O'Shaughnessy, C.A.1, 1Earth and PlanetarySciences, McGill University, 3450 rue University, Montreal, QC H3A2A7; 2Istituto Nazionale di Geofisica e Vulcanologia, sezione di Pisa,Via della Faggiola, 32, 56126 Pisa, Italy; 3SYRMEP Group,Sincrotrone Trieste S.C.p.A., S.S. 14, km 163, 5 in Area Science Park,34149 Basovizza (Trieste)-Italy

Geology is a three-dimensional (3-D) science. We are not merelyinterested in the surface of objects but desire knowledge of theirshapes, orientations and distributions in 3-D, whether we are look-ing at bedded strata on an outcrop and are measuring the strike anddip, or trying to understand the “twists and turns” of an igneousintrusion or a vein of precious ore. Often, however, we must con-tent ourselves with a two-dimensional (2-D) sample, such as a thinsection, because of the difficulty of making 3-D measurements. Inmany cases 2-D samples provide us with a wealth of informationand are sufficient for our studies, but in other cases they fail and atrue 3-D investigation is necessary, especially when quantitativedata are desired. Stereologic techniques can be used to convertsome 2-D measurements into 3-D, but they are often applicableonly to objects of similar shape that are topologically convex (i.e.tangents to the surface do not penetrate the object). Thus, in manygeological cases true 3-D measurements are a necessity. With theadvent of synchrotrons and laboratory microfocus x-ray sources,x-ray computed microtomography has become an easy-to-use toolthat allows the rapid acquisition of 3-D imagery at spatial resolu-tions routinely approaching 1 micron (and in some cases at sub-micron resolution), albeit with the restriction that the higher theresolution the smaller the sample. The reconstructed volumesallow us to quantitatively measure the true 3-D sizes, shapes andspatial orientations of phases in our samples. We have been apply-ing 3-D microtomography to the study of experimentally producedbubbles and of vesicles in natural volcanic rocks in order to betterunderstand the mechanisms involved in magma degassing and therelationship between bubble formation and volcanic eruptions. Thereconstructed volumes allow us to view crystal and bubble textures

directly in 3-D and to measure their 3-D size distributions. But,more than producing “pretty pictures” we can correlate the 3-Ddata with other measurements and also use the reconstructed vol-umes as input into models for the prediction of the behavior of ge-ological materials. In particular, we have been actively modelingthe permeability of vesicular magmas using lattice-Boltzmanntechniques and are now beginning to model the strength of mag-matic foams based upon 3-D microtomographic imagery.

DETAILED CHEMOSTRATIGRAPHY OF THENEOPROTEROZOIC RAPITAN IRON FORMATION,WITH EMPHASIS ON THE REE+Y, Mo, AND U

Baldwin, G.J., Turner, E.C. and Kamber, B.S., Dept. of Earth Sciences,Laurentian University, Sudbury, ON P3E 2C6

Neoproterozoic iron formations represent an unusual and appar-ently final reoccurrence of this sediment type, deposited followinga more than one-billion-year hiatus. Despite the unusual and pos-sibly unique environmental parameters that led to their formation,Neoproterozoic iron formations have strongly influenced deposi-tional models for iron formations of much greater antiquity andplay a crucial role in many ideas regarding the surficial evolutionof the Precambrian Earth. These proposals have been put forwardusing a surprisingly slim database of geochemical data for Neo-proterozoic iron formations. One of the most recognised and well-known of these is the Rapitan iron formation of northwesternCanada. In this study, a suite of high-quality trace element datafrom the Rapitan iron formation was used to reconstruct the con-figuration and redox evolution of the Rapitan basin. Complete,shale-normalized REE+Y patterns demonstrate that the basin waswell connected with the open ocean, demonstrating several diag-nostic features of seawater, such as elevated Y/Ho and Gd/Gd*ratios. Local granitoid catchments also supplied dissolved REE+Y,mainly evident in the subdued shale-normalized La anomaly, sug-gesting partial basin restriction. Molybdenum and U systematicsare very well behaved, but are unrelated to Fe and Mn contents.Combined Mo and U data indicate a partly restricted, or ‘silled’basin. In contrast to modern analogues of such basins, (e.g. theCariaco Basin of Venezuela), the stratigraphic association ofglaciogenic clastic rocks requires the consideration of ice coverin attempts to construct a depositional model. Based on the Moand U metal stratigraphy, we propose that the Rapitan iron forma-tion was deposited in either of the following two basin configura-tions: (1) an ice-capped, stagnant, open-marine basin in whichlong-term redox stratification helped develop euxinic and ferrug-inous water masses; or (2) a combination of a silled basin and icecover, in which permanent restriction at depth was magnified byice-capping of the basin. Regardless of the preferred model, theabsence of a positive Eu anomaly in the Rapitan iron formationsuggests that the open ocean was fully ventilated by this time.

LASER ABLATION WITH FULLY SIMULTANEOUS ICP-MS DETECTION

Barger, W., Ardelt, D. and Primm, O., Spectro Analytical InstrumentsGmbH, Boschstr. 10, 47533 Kleve, Germany,Willi.Barger@ametek.com

Inductively coupled plasma mass spectrometry is a widely usedanalytical method for the elemental analysis and the measurementof isotope ratio’s in geochemistry and is extensively used for thefingerprinting of rocks, minerals and ceramics. The combinationof such an analytical instrument with Laser ablation as a sampleintroduction system has several advantages. Potential errors andcontamination problems are eliminated with a direct measurementof the sample. Also spatially resolved information can be obtained.

Sequential detection of the elements has several disadvan-tages when using laser ablation as a sample introduction system.

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Fluctuations and noise of the laser ablation system as well asflicker noise from the plasma are limiting precision and accuracyof the analytical results.

A completely new detector placed in the focal plane of doublefocusing sector field mass spectrometer in Mattauch HerzogGeometry offers now the possibility to fully simultaneously recordthe signals of all isotopes of the inorganically relevant mass rangefrom a permanent ion beam. This offers new possibilities for thesimultaneous determination of element ratio’s across the completeinorganic relevant mass range as well as simultaneous determina-tion of multiple isotope ratio’s out of one measurement. Whenworking with transient signals, the full duty cycle applies to all el-ements selected and a potential signal skew can be eliminated.

The technologies of this new detector together with the massspectrometer setup and the advantages for Laser Ablation are dis-cussed.

IMPROVED UNDERSTANDING OF SEAFLOORHYDROTHERMAL SYSTEMS USING THE NEPTUNECANADA CABLED OCEAN OBSERVATORY

Barnes, C.R., Best, M.M.R., Heesemann, M., Johnson, F.R., Pautet, L.and Pirenne, B., NEPTUNE Canada, University of Victoria, PO Box1700, Victoria, BC V8W 2Y2, crbarnes@uvic.ca

Steve Scott’s interest in modern seafloor hydrothermal systemsand sulfide deposit genesis was partly generated by volcanic vent-ing and hydrothermal deposits along the Endeavour Segment(2200m), Juan de Fuca Ridge, offshore BC. Earlier submersiblestudies are now supplemented by NEPTUNE Canada (NC), theworld’s first regional cabled ocean observatory, transforming ourunderstanding of biological, chemical, physical, and geologicalprocesses at the spreading ridge and shelf to deep sea relationshipsacross the tectonic plate. Real-time continuous monitoring andarchiving (www.neptunecanada.ca) captures the temporal nature,characteristics, and linkages of these natural processes in wayspreviously impossible.

NC is instrumenting two of five vent fields – Main EndeavourField (MEF) and Mothra. At MEF, temperature-resistivity probes,high-resolution digital camera (or HDTV), McLane remotely ac-tivated fluid sampler and short-period seismometer were installedin 2010. At Mothra, temperature-resistivity probe, microbial in-cubator, McLane fluid sampler and high-resolution digital camerawill be deployed in 2011/12. Many instruments from Universityof Washington, Rutgers University and PMEL/NOAA were mod-ified to be network compatible. In 2010, two trans-ridge cableswere successfully laid connecting to 41 instruments, two junctionboxes, and three interface adapters. Data flowed satisfactorily fora month before the MEF connection failure. A regional circulationexperiment characterizes hydrothermally driven water mass move-ment; one of four mooring arrays was installed north of MEF, withacoustic three-dimensional current meters at 10, 50, 125 and 250m above the seafloor, measuring temperature and salinity varia-tions. A bottom pressure sensor accurately measures local tides. Abroadband seismometer will characterize the overall seismicity tounderstand linkages between local tectonics and biological andoceanographic phenomena. A novel Cabled Observatory ImagingSonar System (COVIS) installed at MEF to acoustically image,quantify and monitor seafloor hydrothermal flow on timescales ofhours (response to ocean tides) to weeks-months-years (responseto volcanic and tectonic events) to advance understanding of theseinterrelated processes.

This Endeavour and later Middle Valley instrumentation willquantitatively document real-time complex interactions amongvolcanic, tectonic, hydrothermal and biological processes. Newusers and instruments are welcomed to utilize the infrastructure’sexpansion capacity.

RESEARCH FRONTIERS ADDRESSED BY CABLEDOCEAN OBSERVATORIES: PERSPECTIVES FROMNEPTUNE CANADA

Barnes, C.R., Best, M.M.R., Johnson, F.R., Pautet L. and Pirenne, B.,NEPTUNE Canada, University of Victoria, PO Box 1700, Victoria, BCV8W 2Y2, crbarnes@uvic.ca

Cabled ocean observatories are transforming the ocean sciences.Examples are drawn from North America, Europe and Asia, butin particular from NEPTUNE Canada (NC) as the world’s first re-gional cabled ocean observatory, off British Columbia’s coast. Itsfinal set of the initial 130 instruments, being deployed in 2011-12,will result in over 400 data streams. Continuous power and highbandwidth facilitates real-time integrated data on physical, chem-ical, geological, and biological gradients at temporal resolutionsrelevant to the dynamics of the earth-ocean system through a rangeof environments, particularly the deep ocean frontier. This allowsdiscrimination between short and long-term events, interactive ex-periments, real time data and imagery, and complex multidiscipli-nary teams interrogating a vast database over the observatory’s25-year design life.

NC’s observatory nodes at the coast, continental slope,abyssal plain, and ocean-spreading ridge are in 100-2660m waterdepths. Principal research frontier themes are: plate tectonicprocesses and earthquake dynamics; dynamic processes of seabedfluid fluxes and gas hydrates; regional ocean/climate dynamicsand effects on marine biota; deep-sea ecosystem dynamics; andengineering and computational research.

The building of this $100M facility integrates hardware, soft-ware, and people networks. Hardware progress includes: installa-tion of the 800km powered fiber-optic backbone (10kV DC and10Gbsec communications); innovative technological developmentof Nodes and Junction Boxes; acquisition/development/testing ofInstruments; development of mobile instrument platforms such asVertical Profiler and Crawler; and integration of over a thousandcomponents into an operating subsea sensor system. Software andhardware systems are developed for acquiring, archiving, and de-livering continuous, free, open, real-time data through the Internet(about 60TB/yr); the web environment combines this data accesswith analysis and visualization, collaborative tools, interoperabil-ity, and instrument control. A network of scientists and techniciansare contributing to the process along with thousands of data users.

Cabled observatories are yielding new knowledge and scien-tific interpretations, including: ocean/climate change, ocean acid-ification, recognizing and mitigating natural hazards,non-renewable and renewable natural resources. Frontier chal-lenges are considerable: new scientific inquiry, technical innova-tions, maximizing educational/outreach activities. Socio-economicbenefits include applications in sectors such as sovereignty, secu-rity, transportation, data services, and public policy.

OXIDE GOLD DEVELOPMENT ABOVEVOLCANOGENIC MASSIVE SULFIDE DEPOSITS:EXAMPLES FROM THE ARABIAN-NUBIAN SHIELD

Barrie, C.T., C.T. Barrie and Associates, Inc., Ottawa, ON,barriect@sympatico.ca, Abufatima, M., Ariab Mining Company,Khartoum, Sudan, and Kjarsgaard, I., Ottawa, ON

Oxide gold deposits above VMS deposits form during weatheringand interaction with the groundwater table under arid and temper-ate conditions, and add considerable value to the economics ofmining the deposit. Classic examples are found in the Neoprotero-zoic Arabian-Nubian shield, including at Bisha in western Eritrea,in the Ariab district of northeast Sudan, and at Al Hajar in southernSaudi Arabia. The oxide gold cap at Bisha has 1.08 M oz Au and4.66 M oz. Ag in 4.8 M tonnes of hematite-dominant, with lesserkaolinite-alunite-sulfate ore (M+I) from the surface to ~35 mdepth. It is underlain by a supergene copper zone (7.5 M tonnes

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@3.96% Cu, M+I+I), and a primary Cu-Zn sulfide zone (26.4 Mtonnes, 0.7 g/t Au, 47.5 g/t Ag, 0.99% Cu, 0.22% Pb, 5.72% Zn,M+I+I). In the Ariab district, at least ten VMS deposits are over-lain by kaolinite-alunite-sulfate dominant oxide gold caps thathave produced >2.2 M oz. Au. The Hassai South deposit is a large(>20 M tonnes), planar, moderately-dipping sulfide lens currentlybe evaluated at depth. The mined oxide ore in the upper 120 me-ters contained native gold, electrum, calaverite, petzite, telluridesof lead, silver and bismuth, native copper, copper oxides and car-bonates, anglesite, cerrusite, and smithsonite. Iron oxides and chal-cedony were redistributed for several tens of meters to either sideof the original sulfide lens into sericite-chlorite schists. The pre-mining surface had massive, brecciated and rebrecciated hematite-goethitesilica formed a 2-20 m-thick cap. Significant native goldis present along fractures and in cavities in the oxide material atsurface.

In this environment, much gold and lead remains in the oxidecaps, whereas copper is more widely distributed, and zinc may benearly absent. Gold is found along fractures and in cavities in ox-ides, sulfates and carbonates, and tends to bind to oxide mineralsurfaces. Gold may migrate in solution, released from the disso-lution of sulfides and sulfosalts; or it may be transported physi-cally if native gold grains are sufficiently large. Lead liberatedfrom sulfides is commonly locked in low solubility anglesite. Cop-per oxides and chalcocite may cement surface gravels abovebedrock and above the groundwater table. Sulfide zinc may formsmithsonite, or it may be washed out of the nearsurface environ-ment. Manganese contents are variable. At Bisha, the surface gos-san is depleted in Mn, whereas exhalites along strike aresignificantly enriched in Mn, reflecting original Mn distributionon the paleo-seafloor.

THE INFLUENCE OF CANADA AND STEVE SCOTT INTHE BUILDING OF PORTUGUESE EXPERTISE INMASSIVE SULPHIDE DEPOSITS AND MARINEGEOLOGY

Barriga, F.J.A.S., Relvas, J.M.R.S., Pinto, A.M.M. and Marques,A.F.A., f.barriga@fc.ul.pt, Creminer FCUL LA-ISR, Fac CienciasUniv Lisboa, Campo Grande, 2780-016 Lisboa, Portugal

The influence of Canada and Steve Scott on the development ofPortuguese VMS expertise has been immense. It all started in thelate 1970’s, when the first Portuguese PhD students in the topicof VMS deposits (and the Iberian Pyrite Belt) went to London,Ontario to work with Bill Fyfe, Dick Hutchinson, Bob Hodder andRob Kerrich.

From then on the links never ceased to strengthen. The aboveCanadians, accompanied by Fred Longstaffe (and others) and yes,Steve Scott, started visiting Portugal rather frequently. At the sametime, the development of a Portuguese scientific team on VMSgenerated the more and more frequent appearance of Portuguesescientists in international meetings. A high turning point was anUMI meeting in Estes Park, Colorado, back in 1993, co-convenedby Steve. Since then, the influence of Steve over our group con-tinued to grow.

Another key event was leg 193 of the Ocean Drilling Pro-gram, in the early 2000’s, to Papua New Guinea, very close toNautilus Minerals Solwara 1 deposit, which will soon become thefirst deep sea VMS mining operation ever. Steve was one of thescientists responsible for the discovery of the target, Pacmanus.Because of ODP rules, only one scientist from the discovery teamcould be co-chief scientist in the expedition. The second co-chiefhad to be invited from a different group. The choice ended in aPortuguese scientist. Steve sailed as a “simple” scientist. What afantastic opportunity to get to know Steve better, both as a scientistand as a colleague! A second Portuguese, Alvaro, an ore mineral-

ogist, sailed as well. Steve and Alvaro spent as much time as theycould over the reflection microscope, finding rare minerals andfluid pathways.

After Leg 193 Steve became a member of the InternationalAdvisory Committee of our research center, Creminer. We havevery strong links with engineers, who better than Steve to help uscommunicate with them? Indeed Steve, over the years, producedmany extremely useful comments and suggestions.

Many of us benefited from Steve’s formal lecturing. Severalgroups of Portuguese graduate students went to Brest (France)year after year to attend the Mineral Deposits Course co-organizedby Steve.

Last but not least, Steve is now in charge of a post-doc fromPortugal, Filipa. She will speak for herself, I will only commentthat the Steve’s participation in our growth continues. Manythanks, Steve, may the force be with you.

PETROLOGICAL, GEOCHEMICAL, ANDPETROGENETIC ANALYSIS OF THE LATE-TECTONICGRENVILLIAN URANIFEROUS LAC TURGEONINTRUSIVE COMPLEX, QUEBEC

Beal, K., k.beal@unb.ca, Lentz, D.R. and McFarlane, C.R.M.,Department of Geology, University of New Brunswick, PO Box 4400,Fredericton, NB E3B 5A3The Lac Turgeon Intrusive Complex (LTIC), along the north

shore of the St. Lawrence Seaway in the Grenville Province ofQuebec, is host to pegmatite-related uranium mineralization. Themain zone has inferred resources of 44 million pounds U3O8, av-eraging 0.012% U3O8; isolated occurrences have up to 0.38%U3O8. The intrusion lithologies include granite, pink pegmatite,and white pegmatite all of which are heterogeneous in texture andhave irregular contacts. The main accessory minerals include bi-otite, muscovite, zircon, illmenite, hematite, and magnetite withminor apatite, uranothorite, uraninite, monazite, and xenotime. U-Pb monazite dating for the granite, white pegmatite, and pink peg-matite yielded ages of 1004.2 ± 4.1 Ma, 1001.9 ± 4.2 Ma, and998.3 ± 5 Ma, respectively. This age corresponds to the terminalstages of the Ottawan Orogeny (1080-1020 Ma) of the GrenvilleOrogenic Cycle that is associated with extension and uplift.

The LTIC is characterized as peraluminous (A/CNK>1) withhigh SiO2 (65-85 wt.%) and most samples are calc-alkaline to al-kali-calcic, have K2O>Na2O, and have low P2O5 and TiO2. Thewhite pegmatite has lower CaO, FeO, and MgO compared to theother phases and is more fractionated with elevated Rb/Sr andRb/Ba and decreased Rb/Cs, K/Rb, and Zr. The chondrite-normal-ized REE patterns for the white pegmatite have a less pronounced,negative Eu/Eu*, and lower ΣREE (average 34 ppm) compared tothe other phases (average 142 ppm for the granite and 94 ppm forthe pink pegmatite). The LaN/LuN is similar for all lithologies(2.1 ± 2.1); however, the REE profile is relatively flat reflectingapatite and monazite fractionation. The LTIC is extremely evolvedas reflected by Rb/Sr (average 5.8 ± 14.0), Rb/Ba (2.7 ± 6.4), andZr/Hf (20.1 ± 7.2) fractionation ratios and Zr (108 ± 194 ppm) andRb (247 ± 107 ppm) abundances. The zircon-, monazite-, and ap-atite-saturation temperatures decrease from the non-mineralizedgranite, pink pegmatite, to the white pegmatite with averages forthe LTIC of 690ºC, 805ºC, and 702ºC, respectively. The LTIC ischaracterized as an A-type granite with a crustal origin followedby additional fractionation.

The U and Th content is highly variable (

IMPACT OF PYRITE ON THE MOBILIZATION OFANTIMONY IN THE MINING ENVIRONMENT

Beauchemin, S., Kwong, Y.T.J., MacKinnon, T., Natural ResourcesCanada, CANMET-MMSL, 555 Booth Street, Ottawa, ON K1A 0G1,sbeauche@nrcan.gc.ca, and Adelman, J., McGill University, NaturalResource Sciences, Ste. Anne de Bellevue, QC

Antimony (Sb) is considered carcinogenic and has been targetedas a priority pollutant by the USEPA, the European Union