Upper limits on the extent of seafloor anoxia during the PETM from uranium isotopes
Clarkson, M.O.; Lenton, T.M.; Andersen, M.B.; Bagard, M.L.; Dickson, A.J.; Vance, D. (2021). Upper limits on the extent of seafloor anoxia during the PETM from uranium isotopes. Nature Comm. 12(1): 399. https://dx.doi.org/10.1038/s41467-020-20486-5
In: Nature Communications. Nature Publishing Group: London. ISSN 2041-1723; e-ISSN 2041-1723, meer
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| Auteurs | | Top |
- Clarkson, M.O.
- Lenton, T.M.
- Andersen, M.B.
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- Bagard, M.L.
- Dickson, A.J.
- Vance, D.
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| Abstract |
The Paleocene Eocene Thermal Maximum (PETM) represents a major carbon cycle and climate perturbation that was associated with ocean de-oxygenation, in a qualitatively similar manner to the more extensive Mesozoic Oceanic Anoxic Events. Although indicators of ocean de-oxygenation are common for the PETM, and linked to biotic turnover, the global extent and temporal progression of de-oxygenation is poorly constrained. Here we present carbonate associated uranium isotope data for the PETM. A lack of resolvable perturbation to the U-cycle during the event suggests a limited expansion of seafloor anoxia on a global scale. We use this result, in conjunction with a biogeochemical model, to set an upper limit on the extent of global seafloor de-oxygenation. The model suggests that the new U isotope data, whilst also being consistent with plausible carbon emission scenarios and observations of carbon cycle recovery, permit a maximum ~10-fold expansion of anoxia, covering <2% of seafloor area. |
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