Orbital climate variability on the northeastern Tibetan Plateau across the Eocene–Oligocene transition

• Published in: Nature Communications
• Main Authors: Ao, Hong, Dupont-Nivet, Guillaume, Rohling, Eelco, Zhang, Peng, Ladant, Jean-Baptiste, Roberts, Andrew, Licht, Alexis, Liu, Qingsong, Liu, Zhonghui, Dekkers, Mark, Coxall, Helen, Jin, Zhangdong, Huang, Chunju, Xiao, Guoqiao, Poulsen, Christopher, Barbolini, Natasha, Meijer, Niels, Sun, Qiang, Qiang, Xiaoke, Yao, Jiao, An, Zhisheng
• Other Authors: Chinese Academy of Sciences Beijing (CAS), Géosciences Rennes (GR), Université de Rennes (UR)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Observatoire des sciences de l'environnement de Rennes (OSERen), Université de Rennes (UR)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Rennes 2 (UR2)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Rennes 2 (UR2)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), Key Laboratory for Orogenic Belts and Crustal Evolution, Peking University Beijing, University of Potsdam = Universität Potsdam, Australian National University (ANU), National Natural Science Foundation of China
• Format: Article in Journal/Newspaper
• Language: English
• Published: CCSD 2020
• Subjects: [SDU.STU.ST]Sciences of the Universe [physics]/Earth Sciences/Stratigraphy; Antarctic; Antarc*
• Online Access: https://insu.hal.science/insu-03006953; https://insu.hal.science/insu-03006953v1/document; https://insu.hal.science/insu-03006953v1/file/Ao-2020.pdf; https://doi.org/10.1038/s41467-020-18824-8

International audience The first major build-up of Antarctic glaciation occurred in two consecutive stages across the Eocene-Oligocene transition (EOT): the EOT-1 cooling event at ~34.1-33.9 Ma and the Oi-1 glaciation event at ~33.8-33.6 Ma. Detailed orbital-scale terrestrial environmental responses to these events remain poorly known. Here we present magnetic and geochemical climate records from the northeastern Tibetan Plateau margin that are dated precisely from ~35.5 to 31 Ma by combined magneto- and astro-chronology. These records suggest a hydroclimate transition at ~33.7 Ma from eccentricity dominated cycles to oscillations paced by a combination of eccentricity, obliquity, and precession, and confirm that major Asian aridification and cooling occurred at Oi-1. We conclude that this terrestrial orbital response transition coincided with a similar transition in the marine benthic δO record for global ice volume and deep-sea temperature variations. The dramatic reorganization of the Asian climate system coincident with Oi-1 was, thus, a response to coeval atmospheric CO decline and continental-scale Antarctic glaciation.