Lithium isotope evidence for enhanced weathering and erosion during the Paleocene-Eocene Thermal Maximum
Pogge von Strandmann, P.A.E.; Jones, M.T.; West, A.J.; Murphy, M.J.; Stokke, E.W.; Tarbuck, G.; Wilson, D.J.; Pearce, C.R.; Schmidt, D.N. (2021). Lithium isotope evidence for enhanced weathering and erosion during the Paleocene-Eocene Thermal Maximum. Science Advances 7(42): eabh4224. https://dx.doi.org/10.1126/sciadv.abh4224
In: Science Advances. AAAS: New York. ISSN 2375-2548; e-ISSN 2375-2548, more
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| Authors | | Top |
- Pogge von Strandmann, P.A.E.
- Jones, M.T.
- West, A.J.
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- Murphy, M.J.
- Stokke, E.W.
- Tarbuck, G.
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- Wilson, D.J.
- Pearce, C.R.
- Schmidt, D.N.
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| Abstract |
The Paleocene-Eocene Thermal Maximum (PETM; ~55.9 Ma) was a geologically rapid warming period associated with carbon release, which caused a marked increase in the hydrological cycle. Here, we use lithium (Li) isotopes to assess the global change in weathering regime, a critical carbon drawdown mechanism, across the PETM. We find a negative Li isotope excursion of ~3‰ in both global seawater (marine carbonates) and in local weathering inputs (detrital shales). This is consistent with a very large delivery of clays to the oceans or a shift in the weathering regime toward higher physical erosion rates and sediment fluxes. Our seawater records are best explained by increases in global erosion rates of ~2× to 3× over 100 ka, combined with model-derived weathering increases of 50 to 60% compared to prewarming values. Such increases in weathering and erosion would have supported enhanced carbon burial, as both carbonate and organic carbon, thereby stabilizing climate. |
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