Evidence of enhanced continental weathering during Oceanic Anoxic Event 2 (OAE 2) in the eastern Asian continental margin

The Cretaceous is characterized by major environmental perturbations at the Earth's surface, including accelerated global warming and Oceanic Anoxic Events (OAEs). Continental chemical weathering may have played a crucial role in triggering OAEs. To evaluate the dominant controls on hinterland chemical weathering throughout the Cretaceous, and to assess whether an acceleration of continental weathering could have triggered OAE 2, this study examines temporal variations in the degree of continental weathering along the eastern Asian continental margin. We calculated the W value, a chemical weathering index derived from major element composition. The overall increasing trend in W values from the Aptian to the Campanian is similar to the pattern of global paleotemperature fluctuations inferred from oxygen isotopes of fossil fish teeth and benthic foraminifers and atmospheric CO 2 concentration. High-resolution measurements interval reveal an abrupt increase in hinterland weathering before the onset of OAE 2 that ceased simultaneously with its termination. Combining previous studies from the Tethys and North Atlantic oceans with our data from the western Pacific margin indicates that enhanced hinterland weathering during the middle Cretaceous was a global and pervasive phenomenon that may have triggered OAE 2.