Sedimentary parameters control the sulfur isotope composition of marine pyrite
Halevy, I.; Fike, D.A.; Pasquier, V.; Bryant, R.N.; Wenk, C.B.; Turchyn, A.V.; Johnston, D.T.; Claypool, G.E. (2023). Sedimentary parameters control the sulfur isotope composition of marine pyrite. Science (Wash.) 382(6673): 946-951. https://dx.doi.org/10.1126/science.adh1215
In: Science (Washington). American Association for the Advancement of Science: New York, N.Y. ISSN 0036-8075; e-ISSN 1095-9203, more
Related to:Bryant, R.N.; Houghton, J.L.; Jones, C.; Pasquier, V.; Halevy, I.; Fike, D.A. (2023). Deconvolving microbial and environmental controls on marine sedimentary pyrite sulfur isotope ratios. Science (Wash.) 382(6673): 912-915. https://dx.doi.org/10.1126/science.adg6103, more
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| Authors | | Top |
- Halevy, I.
- Fike, D.A.
- Pasquier, V.
- Bryant, R.N.
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- Wenk, C.B.
- Turchyn, A.V.
- Johnston, D.T.
- Claypool, G.E.
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| Abstract |
Reconstructions of coupled carbon, oxygen, and sulfur cycles rely heavily on sedimentary pyrite sulfur isotope compositions (δ34Spyr). With a model of sediment diagenesis, paired with global datasets of sedimentary parameters, we show that the wide range of δ34Spyr (~100 per mil) in modern marine sediments arises from geographic patterns in the relative rates of diffusion, burial, and microbial reduction of sulfate. By contrast, the microbial sulfur isotope fractionation remains large and relatively uniform. Over Earth history, the effect of increasing seawater sulfate and oxygen concentrations on sulfate and sulfide transport and reaction may explain the corresponding increase observed in the δ34S offset between sulfate and pyrite. More subtle variations may be related to changes in depositional environments associated with sea level fluctuations and supercontinent cycles. |
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