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Multiple S-isotopic evidence for episodic shoaling of anoxic water during Late Permian mass extinction.

Shen Y, Farquhar J, Zhang H, Masterson A, Zhang T, Wing BA - Nat Commun (2011)

Bottom Line: Global fossil data show that profound biodiversity loss preceded the final catastrophe that killed nearly 90% marine species on a global scale at the end of the Permian.We observe a sulphur isotope signal (negative δ(34)S with negative Δ(33)S) that may have resulted from limitation of sulphate supply, which may be linked to a near shutdown of bioturbation during shoaling of anoxic water.These results indicate that episodic shoaling of anoxic water may have contributed to the profound biodiversity crisis before the final catastrophe.

View Article: PubMed Central - PubMed

Affiliation: CAS Key Laboratory of Crust-Mantle Materials and Environments, School of Earth and Space Sciences, University of Science and Technology of China, Hefei 230026, China. yashen@ustc.edu.cn

ABSTRACT
Global fossil data show that profound biodiversity loss preceded the final catastrophe that killed nearly 90% marine species on a global scale at the end of the Permian. Many hypotheses have been proposed to explain this extinction and yet still remain greatly debated. Here, we report analyses of all four sulphur isotopes ((32)S, (33)S, (34)S and (36)S) for pyrites in sedimentary rocks from the Meishan section in South China. We observe a sulphur isotope signal (negative δ(34)S with negative Δ(33)S) that may have resulted from limitation of sulphate supply, which may be linked to a near shutdown of bioturbation during shoaling of anoxic water. These results indicate that episodic shoaling of anoxic water may have contributed to the profound biodiversity crisis before the final catastrophe. Our data suggest a prolonged deterioration of oceanic environments during the Late Permian mass extinction.

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Related in: MedlinePlus

Plot of Δ33S against δ34S.(a) Plot of Δ33S against δ34S illustrating fields of data produced by sulphate reduction only, sulphate reduction and disproportionation, and mixing between pyrite produced by near quantitative reduction of sulphate and by a combination of sulphate reduction and disproportionation. (b) Plot of Δ33S against δ34S for data from Meishan pyrites illustrating data that get plotted in fields of sulphate reduction and disproportionation, and also mixing between pyrite produced by near quantitative reduction of sulphate and by a combination of sulphate reduction and disproportionation. Grey filled circles are Beds 22–24, black circles are Beds 25–26 and open circles are Beds 27–30.
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f2: Plot of Δ33S against δ34S.(a) Plot of Δ33S against δ34S illustrating fields of data produced by sulphate reduction only, sulphate reduction and disproportionation, and mixing between pyrite produced by near quantitative reduction of sulphate and by a combination of sulphate reduction and disproportionation. (b) Plot of Δ33S against δ34S for data from Meishan pyrites illustrating data that get plotted in fields of sulphate reduction and disproportionation, and also mixing between pyrite produced by near quantitative reduction of sulphate and by a combination of sulphate reduction and disproportionation. Grey filled circles are Beds 22–24, black circles are Beds 25–26 and open circles are Beds 27–30.

Mentions: We report data for all four S-isotopes (32S, 33S, 34S and 36S) of pyrites from the Meishan section, which is the first multiple S-isotopic study on the Permian–Triassic mass extinctions. Sulphur isotope data are presented using delta notation δ34S=[(34S/32S)sample/(34S/32S)reference−1] and capital delta notation Δ33S=[(33S/32S)sample/(33S/32S)reference−((34S/32S)sample/(34S/32S)reference)0.515]. Capital delta and delta values are given in units of per mil (‰). Small deviations for Δ33S and Δ36S can be used to examine the way in which sulphur is cycled in biological and biogeochemical systems2526272829. Figures 1 and 2 (full analytical data available as Supplementary Data 1) present the δ34S and Δ33S data for pyrites from the Meishan section.


Multiple S-isotopic evidence for episodic shoaling of anoxic water during Late Permian mass extinction.

Shen Y, Farquhar J, Zhang H, Masterson A, Zhang T, Wing BA - Nat Commun (2011)

Plot of Δ33S against δ34S.(a) Plot of Δ33S against δ34S illustrating fields of data produced by sulphate reduction only, sulphate reduction and disproportionation, and mixing between pyrite produced by near quantitative reduction of sulphate and by a combination of sulphate reduction and disproportionation. (b) Plot of Δ33S against δ34S for data from Meishan pyrites illustrating data that get plotted in fields of sulphate reduction and disproportionation, and also mixing between pyrite produced by near quantitative reduction of sulphate and by a combination of sulphate reduction and disproportionation. Grey filled circles are Beds 22–24, black circles are Beds 25–26 and open circles are Beds 27–30.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3105335&req=5

f2: Plot of Δ33S against δ34S.(a) Plot of Δ33S against δ34S illustrating fields of data produced by sulphate reduction only, sulphate reduction and disproportionation, and mixing between pyrite produced by near quantitative reduction of sulphate and by a combination of sulphate reduction and disproportionation. (b) Plot of Δ33S against δ34S for data from Meishan pyrites illustrating data that get plotted in fields of sulphate reduction and disproportionation, and also mixing between pyrite produced by near quantitative reduction of sulphate and by a combination of sulphate reduction and disproportionation. Grey filled circles are Beds 22–24, black circles are Beds 25–26 and open circles are Beds 27–30.
Mentions: We report data for all four S-isotopes (32S, 33S, 34S and 36S) of pyrites from the Meishan section, which is the first multiple S-isotopic study on the Permian–Triassic mass extinctions. Sulphur isotope data are presented using delta notation δ34S=[(34S/32S)sample/(34S/32S)reference−1] and capital delta notation Δ33S=[(33S/32S)sample/(33S/32S)reference−((34S/32S)sample/(34S/32S)reference)0.515]. Capital delta and delta values are given in units of per mil (‰). Small deviations for Δ33S and Δ36S can be used to examine the way in which sulphur is cycled in biological and biogeochemical systems2526272829. Figures 1 and 2 (full analytical data available as Supplementary Data 1) present the δ34S and Δ33S data for pyrites from the Meishan section.

Bottom Line: Global fossil data show that profound biodiversity loss preceded the final catastrophe that killed nearly 90% marine species on a global scale at the end of the Permian.We observe a sulphur isotope signal (negative δ(34)S with negative Δ(33)S) that may have resulted from limitation of sulphate supply, which may be linked to a near shutdown of bioturbation during shoaling of anoxic water.These results indicate that episodic shoaling of anoxic water may have contributed to the profound biodiversity crisis before the final catastrophe.

View Article: PubMed Central - PubMed

Affiliation: CAS Key Laboratory of Crust-Mantle Materials and Environments, School of Earth and Space Sciences, University of Science and Technology of China, Hefei 230026, China. yashen@ustc.edu.cn

ABSTRACT
Global fossil data show that profound biodiversity loss preceded the final catastrophe that killed nearly 90% marine species on a global scale at the end of the Permian. Many hypotheses have been proposed to explain this extinction and yet still remain greatly debated. Here, we report analyses of all four sulphur isotopes ((32)S, (33)S, (34)S and (36)S) for pyrites in sedimentary rocks from the Meishan section in South China. We observe a sulphur isotope signal (negative δ(34)S with negative Δ(33)S) that may have resulted from limitation of sulphate supply, which may be linked to a near shutdown of bioturbation during shoaling of anoxic water. These results indicate that episodic shoaling of anoxic water may have contributed to the profound biodiversity crisis before the final catastrophe. Our data suggest a prolonged deterioration of oceanic environments during the Late Permian mass extinction.

Show MeSH
Related in: MedlinePlus