EGU21-12452
https://doi.org/10.5194/egusphere-egu21-12452
EGU General Assembly 2021
© Author(s) 2023. This work is distributed under
the Creative Commons Attribution 4.0 License.

Chemical weathering response to extreme global warming during Paleocene-Eocene Hyperthermals, Southern Pyrenees, Spain

Rocio Jaimes-Gutierrez1, Thierry Adatte2, Emmanuelle Puceat3, Jean Braun4, and Sebastien Castelltort1
Rocio Jaimes-Gutierrez et al.
  • 1Department of Earth Sciences, University of Geneva, Rue des Maraîchers 13, 1205 Geneva, Switzerland (rocio.jaimesgutierrez@unige.ch)
  • 2Institute of Earth Sciences, Géopolis, University of Lausanne, 1015 Lausanne, Switzerland
  • 3Biogéosciences, UMR 6282, UBFC/CNRS, Université Bourgogne Franche-Comté, 6 boulevard Gabriel, 21000 Dijon, France
  • 4Institute of Earth and Environmental Science, Universität Potsdam, 14473 Potsdam, Germany

The Paleocene and early Eocene were periods yielding multiple hyperthermal events. The most pronounced of them was the Paleocene-Eocene Thermal Maximum (PETM), which was characterized by an abrupt increase in global temperature (5–8 °C) over a short time (20 ka). A negative carbon isotope excursion marks the onset of the PETM, which resulted in the fast injection of CO2 into the ocean-atmosphere system, triggering global climatic changes. Geochemical, mineralogical, and sedimentological markers record the resulting increase in continental weathering. This is important, as enhanced chemical erosion influences both the CO2 concentration in the atmosphere and ocean acidity, generating a feedback mechanism. Hence, constraining the rates and intensity of weathering response can further clarify the causes for the PETM and Eocene hyperthermals. This study focuses on the well-preserved Pyrenean foreland basin and intends to assess the continental chemical weathering response of the sediment routing system during the PETM. Clay mineralogy is a climate-sensitive proxy, which records changes in continental erosion. Therefore, clay mineral proportions will be analyzed using X-ray diffraction and major element chemistry on clay-rich samples from the entire source-to-sink system (continental to deep marine deposits). Kaolinite and smectite will be separated from the detrital clay fraction and further subjected to δ18O and δD isotopic analysis for paleoclimatic reconstruction. The combined Lu-Hf and Sm-Nd isotope systems in the clay fraction of the sediments will be used to track the evolution of chemical weathering intensity. The outcome of this project will serve to validate numerical models to understand erosion as a function of rapid climatic change. This topic is of keen interest, as the PETM and its sedimentological signal work as a natural analog for anthropogenically-induced climatic change. The project has received funding from the European Union's Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie Grant Agreement No 860383.

How to cite: Jaimes-Gutierrez, R., Adatte, T., Puceat, E., Braun, J., and Castelltort, S.: Chemical weathering response to extreme global warming during Paleocene-Eocene Hyperthermals, Southern Pyrenees, Spain, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-12452, https://doi.org/10.5194/egusphere-egu21-12452, 2021.

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