Pyrite framboid study of marine Permian–Triassic boundary sections: A complex anoxic event and its relationship to contemporaneous mass extinction

Bond, David P.G.; Wignall, Paul B.

doi:10.1130/b30042.1

Cited by 400 publications

(256 citation statements)

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“…The timing for the onset of widespread oceanic anoxia implied by our results from Dawen is difficult to reconcile with previous hypotheses of persistent anoxia for hundreds of thousands or millions of years prior to the end-Permian extinction event (3,5,6,8). The abrupt increase in Th/U ratios and decrease in δ 238 U that begin at or just below the EH indicate that sustained expanded anoxia did not exist in the Late Permian ocean until immediately prior to the extinction event.…”

Section: Resultscontrasting

confidence: 85%

“…Proposed kill mechanisms have included a nearby supernova, bolide impacts, periods of extreme volcanism (e.g., Siberian Traps), extensive glaciation, and widespread oceanic anoxia (2). Evidence for shallow-ocean anoxia in conjunction with the end-Permian mass extinction is widespread (3)(4)(5)(6), but the intensity and timing of oceanic redox changes remain uncertain (7)(8)(9)(10). Recent hypotheses have invoked the release of hydrogen sulfide gas (H 2 S) from seawater as a kill mechanism (11)(12)(13).…”

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confidence: 99%

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Rapid expansion of oceanic anoxia immediately before the end-Permian mass extinction

Brennecka

Herrmann

Algeo

et al. 2011

Proc. Natl. Acad. Sci. U.S.A.

309

204

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Periods of oceanic anoxia have had a major influence on the evolutionary history of Earth and are often contemporaneous with mass extinction events. Changes in global (as opposed to local) redox conditions can be potentially evaluated using U system proxies. The intensity and timing of oceanic redox changes associated with the end-Permian extinction horizon (EH) were assessed from variations in 238 U∕ 235 U (δ 238 U) and Th/U ratios in a carbonate section at Dawen in southern China. The EH is characterized by shifts toward lower δ 238 U values (from −0.37‰ to −0.65‰), indicative of an expansion of oceanic anoxia, and higher Th/U ratios (from 0.06 to 0.42), indicative of drawdown of U concentrations in seawater. Using a mass balance model, we estimate that this isotopic shift represents a sixfold increase in the flux of U to anoxic facies, implying a corresponding increase in the extent of oceanic anoxia. The intensification of oceanic anoxia coincided with, or slightly preceded, the EH and persisted for an interval of at least 40,000 to 50,000 y following the EH. These findings challenge previous hypotheses of an extended period of whole-ocean anoxia prior to the end-Permian extinction.carbonates | uranium isotopes | paleoredox T he end-Permian extinction represents the largest mass extinction in Earth history, with the demise of an estimated 90% of all marine species (1). While it has been extensively studied, the exact nature and cause of the end-Permian extinction remains the subject of intense scientific debate. Proposed kill mechanisms have included a nearby supernova, bolide impacts, periods of extreme volcanism (e.g., Siberian Traps), extensive glaciation, and widespread oceanic anoxia (2). Evidence for shallow-ocean anoxia in conjunction with the end-Permian mass extinction is widespread (3-6), but the intensity and timing of oceanic redox changes remain uncertain (7-10). Recent hypotheses have invoked the release of hydrogen sulfide gas (H 2 S) from seawater as a kill mechanism (11-13). Such models call upon strong expansion of oceanic anoxia below the oxygenated surface layer to allow buildup of H 2 S, followed by an upward excursion of the chemocline that releases the poisonous gas into the atmosphere (13). In this study, we examine the 238 U∕ 235 U and Th/U (thorium/ uranium) ratios in a carbonate section spanning the end-Permian extinction horizon (EH) to evaluate the timing and scale of these possibilities. Samples for this study were collected from the Dawen section of the Yangtze Block in southern China (Fig. 1), which has been correlated with the global stratotype section and point (GSSP) of the Permian-Triassic boundary at Meishan (14).Due to the geochemical properties of U, the ratio of 238 U∕ 235 U can be used as a tool to investigate the history of ocean oxygenation at a global scale, as opposed to the local redox information provided by most commonly used proxies. The long residence time (∼500 ky) of U in the oceans leads to a homogeneous U concentration in seawater (15, 16), as well as to ...

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Section: Resultscontrasting

confidence: 85%

mentioning

confidence: 99%

Rapid expansion of oceanic anoxia immediately before the end-Permian mass extinction

Brennecka

Herrmann

Algeo

et al. 2011

Proc. Natl. Acad. Sci. U.S.A.

309

204

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“…Framboids growing in the water column have a limited diameter range, as once they have grown to a certain size, they will sink out of the narrow redox interface zone and into oxygen-free bottom water and sediment where further growth is not possible (Wilkin et al 1996;Dustira et al 2013). The smallest mean diameters (3Á5 mm) with a very limited size range are indicative of euxinic conditions (Bond & Wignall 2010). Framboids forming within the sediment under oxic bottom water conditions attain greater diameters on average (7.7 mm) as they reside and grow at the redox interface zone for a longer time (Wilkin et al 1996).…”

Section: Interpretations and Discussionmentioning

confidence: 99%

“…Analyses were carried out with a Carl Zeiss Merlin microscope (Standort Gö ttingen, Vertrieb, Germany) at the Centro de Instrumentació n Científico-Técnica at the University of Jaén, Spain. Framboid size distributions have been successfully applied as anoxia and euxinia indicators in fossil marine sediments (Wignall et al 2005;Shen et al 2007;Bond & Wignall 2010;Liao et al 2010).…”

Section: Methodsmentioning

confidence: 99%

Palaeoenvironment of Eocene prodelta in Spitsbergen recorded by the trace fossilPhycosiphon incertum

2014

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“…They are abundant in low-latitude shallow-marine carbonate shelves in central Tethyan continents where they occupied similar environments to Upper Permian reefs but extended into deeper waters FOREL M.B., Ostracods from the Permian-Triassic boundary in Guizhou (Kershaw et al 2007(Kershaw et al , 2012. Current evidence regarding oxygen levels associated with microbialites growth is conflicting : (i) evidence of low-oxygen conditions (Bond & Wignall 2010;Liao et al 2010;Chen et al 2011), (ii) abundant benthic shelly faunas dominated by ostracods, and occasionally some rare micro-gastropods, microbrachiopods, foraminifers and conodonts (e.g. Crasquin-Soleau & Kershaw 2005;Forel et al 2009;Song et al 2009;Yang et al 2011;Forel et al in press).…”

Section: Introductionmentioning

confidence: 99%

Ostracods (Crustacea) associated with microbialites across the Permian-Triassic boundary in Dajiang (Guizhou Province, South China).

Forel

2012

EJT

451

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Abstract. 26 samples were processed for a taxonomic study of ostracods from the Upper Permian (Changhsingian) -Lower Triassic (Griesbachian) interval of the Dajiang section, Guizhou Province, South China. 112 species belonging to 27 genera are recognized. Five new species are described: Acratia candyae sp. nov, Bairdia adelineae sp. nov., Bairdia? huberti sp. nov., Bairdia jeromei sp. nov., Orthobairdia jeanlouisi sp. nov. The unexpected survival faunas associated with microbial formations in the aftermath of the end-Permian extinction are documented for the first time. Ostracod biodiversity variations and palaeo-environmental modifications associated with microbial growth through the Permian-Triassic boundary (PTB) are discussed.

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Pyrite framboid study of marine Permian–Triassic boundary sections: A complex anoxic event and its relationship to contemporaneous mass extinction

Cited by 400 publications

References 64 publications

Rapid expansion of oceanic anoxia immediately before the end-Permian mass extinction

Rapid expansion of oceanic anoxia immediately before the end-Permian mass extinction

Palaeoenvironment of Eocene prodelta in Spitsbergen recorded by the trace fossilPhycosiphon incertum

Ostracods (Crustacea) associated with microbialites across the Permian-Triassic boundary in Dajiang (Guizhou Province, South China).

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