Asian Aridification Linked to the First Step of the Eocene-Oligocene Climate Transition (EOT) in Obliquity-Dominated Terrestrial Records in Xining Basin, China

摘要

At the Eocene/Oligocene boundary, ca. 34 Ma, the Earth experienced a change from a greenhouse world to an icehouse world. It was also accompanied by a significant global biotic reorganization, known as the Mongolian Remodeling in Asia and the Grande Coupure ("Great Break") in Europe, which is marked by the abrupt replacement of perissodactyl-dominant faunas in Eocene bv rodent/lagomoroh-dominant faunas in Oligocene. The present understanding of the triggering mechanisms, processes and environmental effects of this climatic event is mostly based upon oceanic sediment records and climatic modeling results, studies of terrestrial record with highresolution, however, are rare and poorly constrained. Here, we present a continuous continental record (Tashan Section) from the Xining basin at the northeastern edge in the Tibetan plateau, covering the period between ～35 and 33 Ma.