Geobiology...Meishan China showing bed-by-bed comparison of dated ash-beds as reported by Bowring et al. (1998) and Mundil et al. (2001). Image removed due to copyright restrictions

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12.007 Geobiology Spring 2009

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Geobiology 2009 Lectures 17& 18

Mass Extinctions in the Geological Record

Carbon Cycle Dynamics and Importance of Timescales

virtually all mass extinctions are accompanied by carbon isotopic ‘excursions’ or anomalies indicating disruption of the biogeochemical carbon cycle.

An extinction at the Precambrian-Cambrian Boundary??? Biocomplexity was not fully developed so, although the Cambrian Radiation is undisputed, the existence of an extinction beforehand is

The Devonian Event (Frasnian-Famennian) in passing The Permian Triassic Boundary (PTB)

C-isotopic anomalies, possible mechanisms of extinction

The Paleocene Eocene Boundary (PEB) or Late Paleocene Thermal Maximum

C-isotopic anomalies, evidence for temperature changes, extinction

The K-T Extinction (Cretaceous Boundary Event) An impact-related phenomenon??

Readings and Sources

• A. D. Anbar A. H. Knoll, Proterozoic Ocean

Chemistry and Evolution: A BioinorganicBridge? Science 2002:Vol. 297, 1137 - 1142

• Erwin D.H. (1994) The Permo-TriassicExtinction Nature 367, 231-236

• A.H. Knoll, R. K. Bambach, D. E. Canfield, J.

P. Grotzinger (1996) Comparative EarthHistory and Late Permian Mass ExtinctionScience 273, 455.

• Erwin D.H. (1996) The Mother of MassExtinctions Scientific American 275, 72-78.

• Erwin D.H. (2006) Extinction, Princeton

Other Readings and Sources

• Bedout: A Possible End-Permian Impact Crater Offshore

of Northwestern Australia L. Becker, R. J. Poreda, A. R. Basu, K. O. Pope, T. M. Harrison, C. Nicholson, and R. Iasky Science 4 June 2004; 304: 1469-1476; publishedonline 13 May 2004

• Photic Zone Euxinia During the Permian-Triassic Superanoxic Event Kliti Grice, Changqun Cao, Gordon D. Love, Michael E. Böttcher, Richard J. Twitchett, Emmanuelle Grosjean, Roger E. Summons, Steven C. Turgeon, William Dunning, and Yugan Jin Science 4 February 2005; 307: 706-709; published online 20 January2005

• Cao C., Love G.D., Hays L.E., Wang W., Shen S. and Summons R.E., 2009. Biogeochemical Evidence for a Euxinic Ocean and Ecological Disturbance Presaging theend-Permian Mass Extinction Event. Earth and PlanetaryScience Letters 288, 188-201.

Need to Know

• Nature of evidence for mass extinctions • Names and ages of five mass extinctions

– Importance of geochronology • Which ones attributed to ‘extraterrestrial’ causes

and why • Those which are matched to geobiological

hypotheses – Types of geobiological evidence (isotopes, evidence

of oceanic euxinia, climate change and the characteristics of these at events)

Major Divisions of Earth History

I II III So

lar S

yste

m F

orm

atio

n

Late

Hea

vy B

omba

rdm

ent

Earli

er S

now

ball

Epis

odes

Late

r Sno

wba

ll Ep

isod

es

Archean Proterozoic Phanerozoic

pO2 < 0.002 pO2 > 0.03 pO2 > 0.2 bar bar bar

ferrous oceans

sulfidic oceans

oxic oceans

cyano-bacteria

algae, protists

complex animals & plants

5.0 4.0 3.0 2.0 1.0 0.0

Figure by MIT OpenCourseWare.

Image removed due to copyright restrictions.

Please see Fig. 2 in Shields, Graham, and Veizer, Ján. “Precambrian Marine Carbonate Isotope Database: Version 1.1.” Geochemistry Geophysics Geosystems 3 (June 6, 2002): 12 pages.

Earth’s Surface

Redox vs Time

Intervals between Redox stages marked by putative Snowball Episodes and Extreme Isotopic Excursions

Anbar and Knoll, 2002

Text removed due to copyright restrictions.

Please see Abstract in Anbar, A. D., and Knoll, A. H. “Proterozoic Ocean Chemistry and Evolution: A Bioinorganic Bridge?” Science 297 (August 16, 2002): 1137-1142.

Global Compilation of Late Neoproterozoic Carbon Isotope Excursions and their Relationships to Glaciations

Varanger Glaciation

1000

0

δ13C (VPDB)-10 -5 0 5 10

Arth

ropo

dsCambrian

VendianEd

iaca

ra

531

U-Pbages(Ma)

543.3 1+_

545.1 1+_

548.1 1+_

580?

Spin

y pl

ankt

on

650

+_746 2+_758 4

+_827 6

Stra

tigra

phic

thic

knes

s(c

omm

on sc

ale

exce

pt a

rbitr

ary

for g

laci

atio

n)

-10 -5 0 5 10

Seawater proxy δ13Ccarb850-530 Ma

MoroccoAdoudounian FormationMagaritz et al. (1991)A.C. Maloof (unpubl.) SiberiaTurkut FormationBartley et al. (1998) NamibiaNama GroupSaylor et al. (1998) AustraliaWonoka FormationCalver (2000) OmanHuqf Group - Shuram FmBurns and Matter (1993) NamibiaOtavi GroupHalverson and Hoffman (2003)

SvaibardAkademikerbreen GroupHalverson (2003) AustraliaBitter Springs FormationHill and Walter (2000)

Compilation modified fromHalverson (2003: in prep.)

Marinion Glaciation

Sturtian Glaciation NamibiaGariep GroupFolling and Frimmel (2002)"


Oceanic inorganic-C 42 385 ∼ +0.46

Necrotic-C 4.0 20-40 ∼ -27

Atmospheric-CO2 0.72 4 ∼ -7.5

Living terrestrial biomass 0.56 16 ∼ -27

Living marine biomass 0.007 0.1 ∼ -22

Carbon Reservoirs, Fluxes and Residence Times

δ 13 CSpecies Amount Residence Time (yr)* (in units of 1018 gC) %o PDB**

Sedimentary carbonate-C 62400 342000000 ∼ 0

Sedimentary organic-C 15600 342000000 ∼ -24

Nemotodes most abundantSummary of Animal Phylogeny animals

Ecdysomes- most diversity

Protostomes

Deuterostomes

Animal multicellularity more compl. jelly

tissues, not organs 2layers with jelly

Monophyletic= ‘sister’ to everything single common ancestor

fungi ‘animal protist’ single cell

Bilateral symmetry, Organs

Tissues

Radial symmetry

Individual body plans

490

500

510

520

0 40 80 Temporal Constraints forOrders Burgess shale

Mill

ions

of Y

ears

Bef

ore

Pres

ent

Edia

cara

n A

ssem

blag

e

Late

Middle

Early

Botomian

Atdabanian Tommotian

Nemakit-Daldynian

Cam

bria

nN

eopr

oter

ozoi

c II

IC

ryog

enia

n

-5 0 5

491.0 1.0 Ma 489.0 1.0 Ma

510.0 1.0 Ma+_

+_

+_

+_

+_

531.0 1.0 Ma

522.0 1.0 Ma

543.0 1.0 Ma

555.0 0.3 Ma

565.0 3.0 Ma

575.4 0.4 Ma 580.7 0.7 Ma

-542.0 Ma

+_ +_

+_

+_

+_

fauna Neoproterozoic

530

540

550

560

570

580

590

600

610

620

Classes Cambrian historyFirst trilobites

Shel

ly fo

ssils

Treptichnus pedum

Namacalathus ? and Cloudina Is the base of the

Kimberella

Cambrian an Doushantuo Fm. extinction event??embryos (570 Ma?) Gaskiers glaciation


Namacalathus: more skeletal diversity in

terminal Proterozoic reefs.


Please see Fig. 8a in Grotzinger, John P., et al. “Calcified Metazoans in Thrombolite-Stromatolite of the Terminal Proterozoic Nama Group, Namibia.” Paleobiology 26 (September 2000): 334-359.

Models of Namacalathus

morphology, based on

serial sections through

rocks. Living scyphopolyps

(cnidarians) for comparison.Image removed due to copyright restrictions.

Please see Fig. 10 in Grotzinger, John P., et al. “Calcified Metazoans in Thrombolite-Stromatolite Reefs of the Terminal Proterozoic Nama Group, Namibia.” Paleobiology 26 (September 2000): 334-359.

Precambrian-Cambrian Boundary Extinction ?


Please see Fig. 5 in Knoll, Andrew H., et al. “Early Animal Evolution: Emerging Views from Comparative Biology and Geology.” Science 284 (June 25, 1999): 2129-2137.


Please see Fig. 4.1-1 in Global Biodiversity Assessment. Dowdeswell, Elizabeth, and Heywood, Vernon H., ed. Cambridge, England: Cambridge University Press, 1996. ISBN: 0521564816.

Permo-Triassic Boundary

zWhere is it and how is it defined? z Marine extinctions observed worldwide in the UpperPermian (Changhsingian)

z Base Triassic (Griesbachian) defined at the Global Stratotype, Section and Point , Meishan, China at the first appearance of a specific marine taxon, the conodont Hindeodus parvus

zFloral extinction: well defined ‘coal gap’ in terrestrial sediments worldwide

z eg demise of Glossopteris flora in Australia

z No precisely agreed way to correlate marine and terrestrial sections and an absence of sufficiently accurate geochronology

z Terrestrial faunal extinction (eg Ward et al, Science 2005)

Composite δ13C & Diversity Profiles

Payne et al. Science 305, 506 (2004)


Characteristics of Permian-Triassic Event

• Global regression of seal level; aggregation ofsupercontinent of Pangea; rarity of continuous sedimentation

• Massive volcanism and emplacement of Large Igneous Provinces (LIPS) – 400 to 3700m thick basalts over ca 5 Ma

• Uneven marine extinction; sessile animals worst hit and a terrestrial extinction as well

• Immediate radiation of different physiological groups(disaster species??) than before and then stabilization of theclassic Mesozoic fauna and flora.

• More complex and sophisticated ecosystems; new insectslike today’s and evidence of metabolic versatility eg Claraia which apparently could survive low pO2.

http://volcano.und.nodak.edu/vwdocs/volc_images/north_america w ml

Frequently used decay schemes;

half-lives vary by a factor of > 100

238U Æ 206Pb 4.5 x 109

235U Æ 207Pb 0.71 x 109

40K Æ 40Ar 1.25 x 109

87Rb Æ 87Sr 47 x 109

147Sm Æ 144Nd 106 x 109

Courtesy of USGS.

Zircons: Nature’s Time Capsules/ ashington.ht Acasta: Worlds oldest rock: (Ages in My)

Images removed due to copyright restrictions.

Boundary Clay Bed 25 251-4 Ma (Bowring et al, 1998) Zone of volcanic microspherules

Image and text removed due to copyright restrictions.

Please see Fig. 4 and the final paragraph in Jin, Y. G., et al. “Pattern of Marine Mass Extinction near the Permian-Triassic Boundary in South China.” Science 289 (July 21, 2000): 432-436.


Please see Abstract and Fig. 1 in Mundil, Roland, et al. “Age and Timing of the Permian Mass Extinctions: U/Pb Dating of Closed-System Zircons.” Science 305 (September 14, 2004): 1760-1763.

Combined chemical and heat treatment

Compensates for lead loss

Gives older ages and smaller ‘error’ ellipses


Please see Abstract and Fig. 3 in Mundil, Roland, et al. “Age and Timing of the Permian Mass Extinctions: U/Pb Dating of Closed-System Zircons.” Science 305 (September 14, 2004): 1760-1763.

Older ages better match the age of

Siberian Traps massive volcanism

ie death by association!!

Siberian Traps 251- to 252 Ma

Low

erTr

iass

ic

Perm

ain

Cha

nghs

ingi

an S

tage

Bowring et al (1998) Mundil et al (2001) 38

36

34 30

22

19

16

15

13 12

9

11

9

12 13

15

16

19

22

34 30

36

38

250.2 ± 0.2 253.5 ± 0.4

252.5 ± 0.3

252.0 ± 0.4

257.3 ± 0.7?

250.4 ± 0.5

250.7 ± 0.3 251.4 ± 0.3

252.3 ± 0.3

253.4 ± 0.2

> 254


A simplified stratigraphic column from the Permo-Triassic section at Meishan China showing bed-by-bed comparison of dated ash-beds as reported by Bowring et al. (1998) and Mundil et al. (2001).


Please see Fig. 1 in Jin, Y. G., et al. “Pattern of Marine Mass Extinction near the Permian-Triassic Boundary in South China.” Science 289 (July 21, 2000): 432-436.


Please see Fig. 2 in Jin, Y. G., et al. “Pattern of Marine Mass Extinction near the Permian-Triassic Boundary in South China.” Science 289 (July 21, 2000): 432-436.

PTB Definition Problems

• Age assignments weak in absence of ash beds (mostknown sections worldwide except south China)

• Biostratigraphic age assignments in absence of index fossils are problematic (Parochial vs Cosmopolitan taxa)

• Uncertainties in correlating marine and terrestrial sedimentary sections because fauan/flora don’t overlap

• Multiple isotopic excursions in δa and δo, rare to have both

• Uncertainties in the tempo and ‘causes’ of carbon isotopic excursions

Isotopic pattern

of P/T contact

in Woodada-2

Perth Basin

An ‘excursion’ or

something else

first appearance of

Claraia sp.


Please see Fig. 1 in Foster, C. B., et al. “The Permian-Triassic Boundary in Australia – Organic Carbon Isotopic Anomalies Related to Organofacies, not a Biogeochemical ‘Event’.” In Ninth Annual V. M. Goldschmidt Conference, Abstract #7301.

http://gs.wustl.edu/archives/goldschmidt/1999 /ABSTRCTS/1-400/7301.pdf

http://gs.wustl.edu/archives/goldschmidt/1999 /ABSTRCTS/1-400/7301.pdfhttp://gs.wustl.edu/archives/goldschmidt/1999 /ABSTRCTS/1-400/7301.pdf

PTB Killing Mechanisms

#1 Overturn of an anoxic ocean; CO2 and H2S poisoning

#2 Explosive volcanism and associated icehouse/greenhouse followed by productivity collapse (numerous authors)

#3 Regression, catastrophic methane release and associated greenhouse (numerous authors)

#4 Impact (Becker and Poreda)


#1 Overturn of an anoxic ocean

Comparative Earth History and Late Permian Mass Extinction A. H. Knoll, R. K. Bambach, D. E. Canfield, J. P. Grotzinger

The repeated association during the late Neoproterozoic Era of large carbon-isotopic excursions, continental glaciation, and stratigraphically anomalous carbonate precipitation provides a framework for interpreting the reprise of these conditions on the Late Permian Earth. A paleoceanographic model that was developed to explain these stratigraphically linked phenomena suggests that the overturn of anoxic deep oceans during the Late Permian introduced high concentrations of carbon dioxide into surficial environments. The predicted physiological and climatic consequences for marine and terrestrial organisms are in good accord with the observed timing and selectivity of Late Permian mass extinction

PTB Killing Mechanisms #1 Overturn of an anoxic ocean


#1 Overturn of an anoxic ocean (Holser et al., 1980’s; Kajiwara Paleo-cubed , 1994; Wignall and Twitchett, Science1996; Knoll, Bambach, Canfield and Grotzinger Science 273, 455 (1996); Isozaki, Y. Permo-Triassic Boundary Superanoxia and Stratified Superocean: Records from Lost Deep Sea. Science 276: 235-238 (1997 )

Sulfur & carbon isotope anomalies, extensive deposition of pyrite (Fe++ and H2S)

Analogies to Neoproterozoic glacial times – rapid 13C changes, carbonate crystal

fans etc

Selective susceptibility of animals with no gills, weak internal circulation and low

metabolic rates

Sessile animals such as corals, bryozoans, crinoids and echinoderms

Selective survival and rapid recovery of animals with gills, active circulation, and high metabolic rates

Motile taxa such as Arthropods, Cephalopods (Ammonoids, Nautiloids),

Conodont animals, bivalves


#1 Overturn of an anoxic ocean COASTAL HYPOXIA: CONSEQUENCES FOR LIVING RESOURCES AND ECOSYSTEMS Edited by Nancy N. Rabalais and R. Eugene Turne Coastal and Estuarine Studies Series Volume 58

Preface

Hypoxia is a condition that occurs when dissolved oxygen falls below the level necessary to sustain most animal life. In U.S. coastal waters, and in the entire western Atlantic, we find the largest hypoxic zone in the northern Gulf of Mexico on the Louisiana/Texas continental shelf. The area affected, which is about the size of the state of New Jersey at its maximal extent, has increased since regular measurements began in 1985. Sediment cores from the hypoxic zone also show that algal production and deposition, as well as oxygen stress, were much lower earlier in the 1900s and that significant increases occurred in the latter half of the twentieth century. We publish this book against the background of such measurements, and to review how the developing and expanding hypoxic zone has affected living resources on this continental shelf.

www.agu.org

http://www.agu.org/



NEED TO KNOW: FACT vs. FICTION The dead zone, also known as Gulf hypoxia, has doubled in size since researchers first mapped it in 1985. Despite this trend, last year's swath of oxygen-depleted bottom waters spanned a mere 4,400 square kilometers--only about one fifth of the record size in 1999. Because nitrogen inputs to the Mississippi River Basin have stayed constant, some people have falsely assumed that nitrogen must not cause hypoxia. In reality, factors other than nitrogen can cause the size of the dead zone to fluctuate. Midwestern floods in 1999 washed more nutrients down the Mississippi, for instance, and severe drought caused river levels to drop in 2000. Strong winds over the Gulf of Mexico can also resuscitate salty bottom waters by mixing them with the oxygen-rich river water that usually floats above


#1 Overturn of an anoxic ocean OCEANOGRAPHY Persistent Toxic Gas Eruptions Plague Waters off Namibian Coast The smell of rotten eggs could ruin anyone's day at the beach. But residents of coastal towns in Namibia have become used to the disagreeable smells that accompany frequent eruptions of toxic hydrogen sulfide gas in the area. Now research published in the current issue of the journal Nature suggests that these noxious emissions are much more extensive and persistent than previously thought. Oxygen-starved organic matter decaying on the seafloor in the waters off the coast of southwestern Africa generates the hydrogen sulfide gas. Townspeople know when an eruption has occurred because nearshore fish die and rock lobsters run ashore, fleeing the poisonous water. To get a broader perspective, Scarla Weeks of the University of Cape Town, South Africa and colleagues tracked the gas from afar using satellite imagery. The team observed a region of turquoise-colored, sulfide-infused water that stretched more than 200 kilometers along the coast of the Namib Desert. Moreover, even as the poisonous patch of water moved offshore, a second distinct hydrogen sulfide emission event occurred closer to the coast. Formerly believed to have only limited local consequences, the bursts of hydrogen sulfide could also have long-term effects, according to the report. Because the gas strips oxygen from the water, subsurface hypoxia might linger longer than the gas itself. If so, the authors note, the marine ecology and valuable coastal fisheries of this region could face considerable problems. —Sarah Graham



Nature 415, 493 - 494 (31 Jan 2002) Satellite imaging: Massive emissions of toxic gas in the Atlantic Scarla J. Weeks, Bronwen Currie, Andrew Bakun SUMMARY: Recurrent eruptions of toxic hydrogen sulphide gas in the waters along the Namibian coast off southwestern Africa have been considered to be local features...

PTB Killing Mechanisms #1 Overturn of an anoxic, CO2-rich ocean, hypercapnia and H2S poisoning (Numerous papers prior to 1996; effectively articulated by Knoll, Bambach, Canfield and Grotzinger, Science 1996).

#2 Explosive volcanism and associated icehouse/greenhouse followed by productivity collapse(numerous authors)

#3 Regression, methane release and associated greenhouse (numerous authors)

#4 Impact (Becker et al., Science 291, 1530)


#2 Extensive, incl. explosive volcanism and associated icehouse/greenhouse (numerous authors)

Huge abundances of volcanic spherules in the China PTB sections

Siberian Traps and S. Chinese volcanism but these appear to be long-term events with only partial overlap (see Erwin Sci Am)

More recent instances of massive volcanism had little obvious effect on biodiversity


#3 Regression, methane release and associated greenhouse (numerous authors)

Paucity of Late Permian and E. Triassic sediments and continuous

sedimentation

rapid 13C and repeated excursions

Loss of habitat for sessile animals such as corals, bryozoans,

crinoids and echinoderms

Selective survival of mobile animals such as Arthropods,

Cephalopods (Ammonoids, Nautiloids), conodont animals, bivalves

(Knoll et al; Jin et al)

Methane on Earth

http://woodshole.er.usgs.gov/project-

pages/hydrates/what.html

http://woodshole.er.usgs.gov/project-pages/hydrates/what.htmlhttp://woodshole.er.usgs.gov/project-pages/hydrates/what.html

Methane

http://woodshole.er.usgs.gov/project-pages/hydrates/what.html

http://woodshole.er.usgs.gov/project-pages/hydrates/what.html

Hydrate seams in mud

Hydrate outcropping on seafloor and colonised

by chemosynthetic ecosystem


#4 Impact (Becker and Poreda) Fig. 1. LDMS of the Meishan, China, and Sasayama, Japan, boundary sediments. (A) LDMS spectrum of Meishan (toluene) extract, showing peaks at m/z of 720 and 840 amu (C60+ and C70+). (B) LDMS spectrum of

Image removed due to copyright restrictions. Meishan (TMB) extract, showing a small mass peak for C60+ and a range of larger carbon clusters between C70+ and C160+. (C) The higher fullerenes in the Sasayama (TMB) extract

(Becker et al., Science 291, 1530)


Buckminsterfullerene Buckminsterfullerene (IUPAC name (C60-Ih)[5,6]fullerene) is the smallest fullerene in which no two pentagons share an edge (which can be destabilizing — see pentalene). It is also the most common in terms of natural occurrence, as it can often be found in soot.

The structure of C60 is a truncated T=3 icosahedron, which resembles a soccer ball of

the type made of hexagons and pentagons, with a carbon atom at the corners of each

hexagon and a bond along each edge.

The C60 molecule has two bond lengths. The 6:6 ring bonds (between two hexagons)

can be considered "double bonds" and are shorter than the 6:5 bonds (between a

hexagon and a pentagon).

In molecular beam experiments, discrete peaks were observed corresponding to molecules with the exact mass of sixty or seventy or more carbon atoms. In 1985, Harold Kroto (then of the University of Sussex, now of Florida State University), James R. Heath, Sean O'Brien, Robert Curl and Richard Smalley, from Rice University, discovered C60, and shortly after came to discover the fullerenes. Kroto, Curl, and Smalley were awarded the 1996 Nobel Prize in Chemistry for their roles in the discovery of this class of compounds

http://en.wikipedia.org/wiki/IUPAChttp://en.wikipedia.org/wiki/Pentalenehttp://en.wikipedia.org/wiki/Truncated_icosahedronhttp://en.wikipedia.org/wiki/Football_%28ball%29http://en.wikipedia.org/wiki/Double_bondhttp://en.wikipedia.org/wiki/Mass_spectroscopyhttp://en.wikipedia.org/wiki/Harold_Krotohttp://en.wikipedia.org/wiki/University_of_Sussexhttp://en.wikipedia.org/wiki/Florida_State_Universityhttp://en.wikipedia.org/wiki/Se%C3%A1n_O%27Brienhttp://en.wikipedia.org/wiki/Robert_Curlhttp://en.wikipedia.org/wiki/Richard_Smalleyhttp://en.wikipedia.org/wiki/Rice_Universityhttp://en.wikipedia.org/wiki/Nobel_Prize_in_Chemistryhttp://en.wikipedia.org/w/index.php?title=James_R._Heath&action=edit

3He as a tracer

Extraterrestrial 3He is the major source

– From solar wind and implanted in bolides and IDP – 3He/ 4He = 100 (ET) Ra vs 0.03 Ra (Terrestrial He) normalized

to atm. value of 1.39 x 10-6 – Vaporized from bolides and large IDP by heat on entry – Retained in small IDP and normally accrete uniformly – Can give estimated of sedimentation rate independent of

absolute time – Enhanced accretion during ‘dusty’ episodes such as comet

showers – All He leaks so not useful over >400Ma timescales

PTB Killing Mechanisms #4 No 3He evidence for impact

(K. A. Farley and S. Mukhopadhyay, Science 293, 2343a, 2001)


Because the "3He

from Sasayama is significantly older

PTB Killing Mechanisms enriched" sample

#4 Impact (Becker and Poreda) ?? than Meishan Bed 25, they cannot have been from the same impact event. Yukio Isozaki

In other words, in Japan, this bed is Permian


(Becker et al., Science 291, 1530)

Science, Vol 304, Issue 5676, 1469-1476, 4 June 2004

Fig. 1. Positions of the continents during end-Permian time. Red dots denote where extraterrestrial fullerenes have been reported. In addition, other suggested impact tracers have been found in P-T boundary layers at Graphite Peak, Antarctica; Meishan, China; and Sasayama, Japan, including meteoritic debris (8), Fe-Ni-Si grains (5, 8), shocked quartz (4), and impact spherules (6). Recently, large shocked quartz grains (fig. S1) were found in the Fraser Park, Australia, and Graphite Peak, Antarctica, P-T boundary layer (yellow dot). [The Permian map was modified from the Scotese Paleomap Project Web site (www.scotese.com).] [View Larger Version of this Image (61K GIF file)] [Return to Article]

http://www.scotese.com/http://www.sciencemag.org/cgi/content/full/304/5676/1469/FIG1http://www.sciencemag.org/cgi/content/full/304/5676/1469#FIG1

Fullerene analysis of Meishan PTB sediment by negative ion mass spectrometry

13C-enriched C60727- 742 Da

13C-enriched C60O

No detectable ‘natural’ C70

840 Da

No detectable

‘natural’ C60720 Da

C60720.0 C60O

736.0

C60O2752 + 753 Da

sta

sed

13C fullerene-spiked toluene extract of Meishan Bed 25

authentic fullerene standard (3.5pg)

ndards and toluene extracts of crushed & demineralized iments were analyzed by ESI-

TOF MS

Biogeochemical Carbon Cycle in Modern Ocean

hν

sediment

CO2 + H2O Æ CH2O + O2 PhotosynthesisÅ Respiration

H2S + 2CO2 + 2H2O Å CH3COOH + SO42-+ 2H+ Sulfate Reduction

Links Between Carbon and Sulfur Cycles

hν

sediment

CO2 + H2O Æ CH2O + O2 PhotosynthesisÅ Respiration


Carbon Cycle in a Stratified Ocean

hν

sediment

CO2 + H2O Æ CH2O + O2 Photosynthesis


Euxinic Water Column

Green sulfur bacteriaChlorobiaceae

O2

H2S

Green-pigmentedChlorobiaceae

Brown-pigmentedChlorobiaceae

hν

sediment

20 m

100 m

Anoxygenic photosynthesis

H2S + CO2

hν

chlorobactane

SO 2-4 + Corgisorenieratane

● requires reduced sulfur

● requires light

● strictly anaerobic

Biomarkers of Chlorobiaceae

Summons et al., 1987

-

C40 carotenoid

C-C bond cleavage

*C40 isorenieratane(preserved extractable HC)

free isorenieretene(found in Chlorobiumsp.)

cyclisation/ aromatisation

free and boundcomplex polyaromatichydrocarbons

H2S / H2

covalently-bound (partially reduced)isorenieretene

C-C bond cleavage

covalently-bound isorenieratane(fully reduced)

H2S / H2

S-S and C-S linkage cleavage

S

S

S

*C14-30 aryl isoprenoids(preserved extractable HCs)

Molecular Markers for Chlorobiaceae

Biolipid precursor

m/z = 133/134m/z = 133/134

Damsté, De Leeuw et al., 1990-1995

Identification of Isorenieratane at the PTB

Isorenieratane unambiguous marker for ‘brown pigmented’strains of Green Sulfur Bacteria Æ

H2S at 80 -100m from surface

Meishan Stratigraphy & Radiometeric Ages

0 1 2 3 4 5 -1-2 (PDB)

253.5

253

252.5

252

251.5

251

250.5

250

249.5 (Ma)

34-36

33 29-32

28

27

26

25

23-24

22 21 20 17 15

12-14 11 9

8

7

1- 6

Lithological Column

Bed No.


30 samples from beds 22 to 39 (ca. 3 Ma)

molecular lipid biomarkers

bulk geochemical parameters (TOC, δ13Corg, δ15Norg)

Meishan-1 core drilled Jan 2004

Multiple radiometric ages help constrain pace Ash in bed 25 = 251.4 ± 0.3 Ma, Bowring et al, 1998)

252.6 ± 0.2 Ma Mundil et al, 2004

Paleographic Reconstruction: Ron Blakey, Northern Arizona University

http://jan.ucc.nau.edu/rcb7/presentmoll.jpgCourtesy Ron Blakey. Used with permission.

http://jan.ucc.nau.edu/rcb7/presentmoll.jpg

http://jan.ucc.nau.edu/

50 Ka

Courtesy Ron Blakey. Used with permission.



20 Ma



35 Ma

http://jan.ucc.nau.edu/Courtesy Ron Blakey. Used with permission.



50 Ma




65 Ma




90 Ma




105 Ma




120 Ma




150 Ma




170 Ma




200 Ma




220 Ma




240 Ma




260 Ma



Meishan sediments deposited on N.-E. margin of Paleotethysequatorial latitudes, deepwater shales

Meishan Section


Please see http://www.scotese.com/images/255.jpg

http://www.scotese.com/images/255.jpg

Meishan (Core 1)Bulk geochemical parameters

-115

-110

-105

-100

-95

-90

-850 2 4 6

Pristane/Phytanede

pth/

m

-115

-110

-105

-100

-95

-90

-85

-34 -32 -30 -28 -26 -24 -22

δ13Corg ( kerogen)

dept

h/m

-115

-110

-105

-100

-95

-90

-850 0.5 1.0 1.5

TOC/wt%

dept

h/m

37-2 37-2 37-2

dysoxic

34-1

anoxic

34-1

22-3 22-3

26-3

22-3

26-3

23-423-423-4

24-6 24-624-626-3

32-3

29-1

34-1

Identification of Isorenieratane at the PTB

standard

sample

Isorenieratane indicative of ‘brown pigmented’

Green Sulfur Bacteria Æ

H2S 20 -100m from surface

Images removed due to copyright restriction.

Please see Fig. 1a in Grice, Kliti, et al. “Photic Zone Euxinia during the Permian-Triassic SuperanoxicEvent.” Science 307 (February 4, 2005): 706-709.andFig. S2 in the associated Online Supplement.

115

110

105

100

95

90

85

0 1 2

Dep

th (m

)

0 1 2 3 4 5 6

TOC (wt%) δ13C kerogen (‰VPDB) Pristane/Phytane Aryl isoprenoids (ppm TOC) Isorenieratane (ppm TOC)

bed 25bed 26

-32 -28 -24

bed 24

0 2 4 6

bed 24

bed 27

bed 37

0 2 4 6 8 10

C18

C19

C20

bed 37

bed 35

bed 30

Abundance of GSB BiomarkersMeishan-1 core

Intense euxinia in Late Permian Bed 24

euxinia repeatedly in Triassic

δ15N of Meishan Organic Matter

z Positive values (+3 to +2) in late Permian Beds 22-24

z Trend to zero or negative values of δ15N in latest Permian reflects depletion of nitrate/nitrite pool driven by euxinic cond.

zLarge swings in E. Triassic may reflect waxing and waning of euxinia

z Predominantly cyanobacterial primary production

-115

-110

-105

-100

-95

-90

-85-4 -2 0 2 4

δ15N kerogen

dept

h/m

26-2

22-323-4

34-334-1

34-12

b24

30-1

35-1 35-2

36-3

37-2

-ve +ve

Peaks of aryl isoprenoidabundance

Peaks in 2-MeHI >15%

Hopane/Sterane and Methylhopane ratios for Meishan Core

Extremely high cyanobacterial inputIn top of bed 34-bed 36

Hop/st> 100 in beds 35/36(max. 190!)

-115

-110

-105

-100

-95

-90

-850 10 20 30

% 2Me/(2Me + des)

dept

h/m

37-2

26-3

22-3

24-2

34-12

36-3

39-1

-115

-110

-105

-100

-95

-90

-8540 60 80 100

%(2/2+3) Me hopane

26-3

22-3

24-2

34-12

36-3

39-1

34-1

-115

-110

-105

-100

-95

-90

-85

1 10 100 1000

hopane/sterane

dept

h/m

36-337-2

34-12

34-134-1

30-1

22-3

24-6

Central Tethys Ocean Section

Present-day Tibet

http://www.scotese.com

m/z = 134Twitchett‘D’ Section Outcrop

5.00 30.00 35.00 40.00 45.00 50

36.5439.09

41.78

36.5439.09

41.78

36.5439.07

41.78

36.54

33.2831.43

28.92

39.09

41.7845.20

33.26

28.4025.51

36.54

39.0741.78

48.7145.48

16

1819

2021

17

5.00 30.00 35.00 40.00 45.00 50

36.5439.09

41.78

36.5439.09

41.78

36.5439.07

41.78

36.54

33.2831.43

28.92

39.09

41.7845.20

33.26

28.4025.51

36.54

39.0741.78

48.7145.48

16

1819

2021

17

Aryl isoprenoids



http://www.scotese.comhttp://www.scotese.com/images/255.jpg

Great Bank of Guizhou


PGD 84

Meishan

PGD-104

12.00 16.00 20.00 24.00 28.00

14

15 1618 19 20

21

17

PGD 84

Meishan

PGD-104

12.00 16.00 20.00 24.00 28.0012.00 16.00 20.00 24.00 28.00

14

15 1618 19 20

21

17

Aryl isoprenoids m/z 134

~ 250 Ma

~ 251 Ma


Please see Fig. 1 in Payne, Jonathan L., et al. “Large Perturbations of the Carbon Cycle DuringRecovery from the End-Permian Extinction.”Science 305 (July 23, 2004): 506-509.





Peace River EmbaymentTriassic rocks to east of dashed line

are in the subsurface.


Calais, Crooked Creek + other cores ~ 25 km apart




Hindeodus parvus from subsurface Montney Fm., Western Canada

Calais and Cr. Ck samples are from parvus Zone and younger

STRATIGRAPHYRESEARCH GROUP

APPLIED

Modified from Henderson, 1997.

Tria

ssic

Low

erM

IDD

LE

LOW

ER ANISIAN

SPATHIAN

SMITHIAN

DIENERIAN

GRIESBAC-HIAN

CHANGHSIN-GIAN

WUCHIAPIN-GIAN

CAPITANIAN

WORDIAN

Upp

er

Perm

ian

bitteri

rosenkrantzi-postbitteri

shenimeishanensis

isarcica

parvus-taylorae

Kummeli

cari

nata

-pl

anat

a

cristagalli

pakistanensis

waagenimilleri

homericollinsoni

triangularisjubata

regale

timorensis

BIOZONESTAGESYSTEM FORMATION

Doig Fm.

Toad

Fm

.G

rayl

ing

Fm.

Ellis

onia

condensedbasal SulphurMountain Fm.

??

Belloyor

Ranger Canyonor

Fantasque Fm.

Mowitch

Mon

tney

Fm

.Su

lphu

r Mt.

Fm.

Pach

ycla

dina

??


Aryl isoprenoids present in 7 samples from 4 wells at the H. parvus level

20.00 40.00 60.00 80.00 100.00

RI m/z 134.00

100

ABR016 Chevron Crooked Creek 3500ftAromatic hydrocarbons

isorenieratane

β- isorenieratane

14

15

16

18

19 20

2117


Kap StoschLate Permian to Early Triassic rocks from outcrop

Curt Teichert, and Bernhard Kummel Bulletin of Canadian Petroleum Geology; December 1972; v. 20; no. 4; p. 659-67Permian-Triassic boundary in the Kap Stosch area, east Greenland Kap Stosch




Barney Ck. Fm aromatic hydrocarbon fraction Æretention standard for 2,3,6-trimethylaryl

isoprenoids

isorenieratane

16 18

19

2022

21

16

isorenieratane

1819

20

22

19990456 aromatic hydrocarbon fractionGreenland, Kap Stosch

Upper Permian; loc 13.75

C# of aryl isoprenoid

21

SIM m/z = 134.1

SIM m/z = 134.1

16

1819

20

22

19990445 aromatic hydrocarbon fractionGreenland, Kap StoschLower Triassic; loc 1

isorenieratane21

SIM m/z = 134.1

10080604020

Time min.

Hydrogen sulfide poisoning?

Grice et al. Science, 2005

z Spread of anoxic and sulfidic waters onto continental shelves

Kump, Pavlov and Arthur, Geology 33 (May) 2005

z Flux of H2S to the atmosphere that depletes hydroxyl radicals in the troposphere

z H2S plume would be persistent; could poison terrestrial biota

PTB SummaryCharacteristics

z Extinction selectively killed sessile organisms with calcareous skeletons; vertebrates less affected

z Recovery was very protracted > 10 million years

z Biomarker and isotopic evidence for deep ocean euxniaacross P-T

z Multiple excursions in δ13Ccarb , δ13Corg, δ15Norg, δ34Spyritenear boundary

z These anomalies indicate there were major, long-termchanges in the redox state of the ocean and a long-termdisruption of the C-cycle

z Evidence for near-surface euxinia at PTB from 5 localities Æ Tethys and Panthalassic were euxinic Æ compelling extinction mechanism

PTB SummaryH2S in ocean & atmosphere toxic to all but bacterial life

What are the underlying causes of this oceanic euxinia?z The ‘complex web of causality’z Aggregation of Pangea in greenhouse worldÆ low

equator-pole temperature differentialÆ sluggish ocean circulation

zMassive weathering of Paleozoic coals Ædrawdown of pO2 and rise of pCO2; OM for SRB

z Long delay in recovery until ocean is re-ventilatedz Environmental disturbance may have been made

more extreme due to intense volcanism


Loci of Aryl Isoprenoid OccurrencesMeishan

N.-E. margin Paleotethysequatorial, deepwater

shale & carb.

Kap Stoschmid N. lat., paralic shales

Perth BasinHigh S. lat. Tethys,

paralic shales

TibetS. lat., Tethyscarbonates

Peace River Embaymentmid N. lat., Panthalassa,

paralic shales

Great Bank of GuizhouE. margin of Paleotethysequatorial, carbonates




Carbon Cycle Dynamics (Berner RA, PNAS, 99, 4172

2002)

Image removed due to copyright restrictions. Please see Fig. 2 in Bowring, S. A., et al. "U/Pb Zircon

Geochronology and Tempo of the End-Permian Mass Extinction." Science 280 (1998): 1039-1045.

Carbon Cycle

Dynamics

Structure of GeoCarb

Model of sources and sinks

of carbon

Fig. 2. Diagram for the carbon cycle box model used in the present paper. Fv flux of volcanic CO2; Fm flux of methane from methane hydrates (the methane is assumed to be oxidized to CO2 essentially instantaneously); Fwc uptake of CO2 by means of the weathering of carbonates (twice this value is the flux of carbon to the oceans from carbonate weathering); Fwsi uptake of atmospheric CO2 by means of the weathering of Ca–Mg silicates with transfer of the carbon to the oceans; Fbg burial flux of organic carbon in sediments; Fwg weathering flux of ancient sedimentary organic carbon (kerogen); Fbio flux of CO2 caised by the mass mortality of terrestrial biota; Fbc burial flux of marine carbonates ( flux of CO2 from ocean to the atmosphere). Modified from Beerling and Berner (18).

Fig. 1, 2, 3, 4, 5, 6, and 9 from Berner, Robert A. "Examination of Hypotheses for the Permo-Triassic Boundary Extinction by Carbon Cycle Modeling." PNAS 99 (April 2, 2002): 4172-4177. Copyright 2002 National Academy of Sciences, USA.

Carbon Cycle

Dynamics

Methane hydrate collapse and oxidation at realistic rates, with oxidation to CO2 on realistic timescales can explain observed large carbon isotopic shifts.

However, resultant pCO2 increase is not as high as seen through most of Mesozoic so cannot have killed by hypercapnia (CO2 poisoning).

Fig. 3. Plots of oceanic 13C and atmospheric CO2 vs. time as a result of the input of methane hydrate-derived CH4 to the atmosphere or oceans. It is assumed that the methane is oxidized essentially instantaneously to CO2 in either case. (A) 13C. (B) CO2.


Carbon Cycle

Dynamics

Volcanism and CO2 release at realistic timescales cannot explain observed carbon isotopic shifts.

May have been a contributory factor

Fig. 4. Plots of oceanic 13C and atmospheric CO2 vs. time as a result of the input of volcanically derived CO2. The terms fast and slow refer to inputs lasting approximately 30,000 and 200,000 years, respectively. (A) 13C. (B) CO2.


Carbon Cycle Dynamics

Fig. 5. Plots of 13C and atmospheric CO2 vs. time Fig. 6. Plots of oceanic 13C and atmospheric CO2 for the sudden mass mortality of terrestrial vs. time as a result of a sudden drop in global vegetation with all vegetation plus soil carbon organic C burial rate from 60 Gt C/kyr to 24 Gt converted to CO2. Note the much shorter time C/kyr with a constantly maintained organic C scale compared with Figs. 3 and 4. weathering rate of 60 Gt C/kyr.

Alone, mass mortality, productivity collapse, OM remineralization, CO2 release and cessation of biological pump at realistic timescales cannot explain observed carbon isotopic shifts or generate toxic amounts of CO2. Cannot have been the sole cause but may have been a contributory factor


Carbon Cycle Dynamics

Fig. 9. Plots of 13C and CO2 vs time for the combined inputs of carbon to the atmosphere from mass terrestrial mortality, CH4 hydrate decomposition, and volcanic CO2 degassing combined with an imbalance in the rates of burial and weathering of sedimentary organic matter.

A combination of productivity collapse, imbalance between burial and weathering, CH4 release and volcanic degassing at realistic timescales can explain observed carbon isotopic shifts and amounts of CO2 sufficient to create intense greenhouse.



#5 Tangled web of causality

Erwin, Nature 367, 231 (1994); Berner PNAS 99, 4172 (2002) Regression = loss of habitat

Exposure of supercontinent (Pangea) exacerbates loss of habitat

Large supercontinent and its paleogeography = a deep ocean that might more

easily become anoxic

Volcanism, XS CO2, warming, productivity collapse

However, cannot sustain exceedingly high CO2 in presence of limestone on ocean

floor because this dissolves with a buffering effect

Rapid E. Triassic transgression destroyed coastal habitat and contributed to

floral extinctions

Terrestrial primary productivity on the land replaced by primary productivity in

ocean Æ reorganization of C-cycle (Berner)

Geobiology 2009�Lectures 17& 18�Mass Extinctions in the Geological Record Slide Number 2Slide Number 3Need to KnowPermo-Triassic BoundarySlide Number 17Slide Number 18Slide Number 19Slide Number 20Composite d13C & Diversity Profiles Payne et al. Science 305, 506 (2004)Characteristics of Permian-Triassic EventPTB Killing MechanismsPTB Killing Mechanisms�#1 Overturn of an anoxic oceanPTB Killing MechanismsPTB Killing MechanismsPTB Killing MechanismsPTB Killing MechanismsPTB Killing MechanismsPTB Killing MechanismsPTB Killing MechanismsPTB Killing MechanismsPTB Killing MechanismsMethane on EarthMethaneSlide Number 44PTB Killing MechanismsSlide Number 463He as a tracerPTB Killing MechanismsPTB Killing MechanismsSlide Number 50Slide Number 52Slide Number 53Slide Number 54Slide Number 55Slide Number 56Slide Number 57Identification of Isorenieratane at the PTBPTB Killing Mechanismsnn.pdfEarth’s Surface Redox vs TimeSummary of Animal PhylogenyNamacalathus: more skeletal diversity in terminal Proterozoic reefs.Models of Namacalathus morphology, based on serial sections through rocks. Living scyphopolyps (cnidarians) for comparison.

nn.pdfSiberian Traps 251- to 252 MaPTB Definition ProblemsIsotopic pattern of P/T contact in Woodada-2�Perth Basin�An ‘excursion’ or something else

nn.pdfIdentification of Isorenieratane at the PTBPTB SummaryPTB SummaryCarbon Cycle Dynamics (Berner RA, PNAS, 99, 4172 2002)Carbon Cycle Dynamics��Structure of GeoCarb Model of sources and sinks of carbonCarbon Cycle DynamicsCarbon Cycle DynamicsCarbon Cycle DynamicsCarbon Cycle Dynamics

Documents

Geobiology...Meishan China showing bed-by-bed comparison of dated ash-beds as reported by Bowring et al. (1998) and Mundil et al. (2001). Image removed due to copyright restrictions