This study investigates hydrologic perturbations during the Paleocene-Eocene Thermal Maximum (PETM) using clay mineral hydroxyl isotopes from the North Sea Basin. The authors demonstrate that hydroxyl isotopes in clays are less susceptible to compositional changes than bulk isotopes, providing a more accurate proxy for hydrologic variability. A significant decrease in clay OH hydrogen isotope values (~8‰) at the PETM onset, coinciding with increased kaolinite, indicates enhanced rainfall and weathering. This suggests an amplified hydrologic cycle response to global warming, particularly during the early PETM. Hydrologic changes were short-lived compared to carbon cycle perturbations, with isotope values returning to pre-PETM levels well before the CIE's end.

Gregory L. Walters, Simon J. Kemp, Jordon D. Hemingway, David T. Johnston, David A. Hodell