Onset of aridification by 34 Ma across the Eocene-Oligocene transition in Central Asia

Research Article| November 01, 2015 Onset of aridification by 34 Ma across the Eocene-Oligocene transition in Central Asia Jimin Sun; Jimin Sun * 1State Key Laboratory of Cenozoic Geology and Environment, Institute of Geology and Geophysics, Chinese Academy of Sciences, P.O. Box 9825, Beijing 100029, China2CAS (Chinese Academy of Sciences) Center for Excellence in Tibetan Plateau Earth Sciences, Beijing 100101, China *E-mail: jmsun@mail.igcas.ac.cn Search for other works by this author on: GSW Google Scholar Brian F. Windley Brian F. Windley 3Department of Geology, University of Leicester, University Road, Leicester LEI 7RH, UK Search for other works by this author on: GSW Google Scholar Author and Article Information Jimin Sun * 1State Key Laboratory of Cenozoic Geology and Environment, Institute of Geology and Geophysics, Chinese Academy of Sciences, P.O. Box 9825, Beijing 100029, China2CAS (Chinese Academy of Sciences) Center for Excellence in Tibetan Plateau Earth Sciences, Beijing 100101, China Brian F. Windley 3Department of Geology, University of Leicester, University Road, Leicester LEI 7RH, UK *E-mail: jmsun@mail.igcas.ac.cn Publisher: Geological Society of America Received: 16 Jul 2015 Revision Received: 15 Sep 2015 Accepted: 16 Sep 2015 First Online: 09 Mar 2017 Online ISSN: 1943-2682 Print ISSN: 0091-7613 © 2015 Geological Society of America Geology (2015) 43 (11): 1015–1018. https://doi.org/10.1130/G37165.1 Article history Received: 16 Jul 2015 Revision Received: 15 Sep 2015 Accepted: 16 Sep 2015 First Online: 09 Mar 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn Email Permissions Search Site Citation Jimin Sun, Brian F. Windley; Onset of aridification by 34 Ma across the Eocene-Oligocene transition in Central Asia. Geology 2015;; 43 (11): 1015–1018. doi: https://doi.org/10.1130/G37165.1 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyGeology Search Advanced Search Abstract Cenozoic climate has changed markedly from a warm, wet climate to the present cool, dry glacial-interglacial cycles. The largest of these cooling steps is thought to have taken place across the Eocene-Oligocene transition. Terrestrial airborne eolian loess is a direct result of land aridification; therefore, the prolonged formation of thick eolian loess deposits provides a key to aridification history in the geological past. However, the oldest eolian loess in the Asian interior has been dated to only 25–22 Ma. Here we present new sedimentological, geochemical, and magnetostratigraphic data from Cenozoic sections in southwestern Mongolia to show that the earliest eolian dust accumulation occurred by 34 Ma, ∼10 m.y. earlier than currently believed. We suggest that this oldest eolian dust accumulation provides direct evidence for enhanced aridification across the Eocene-Oligocene transition in Central Asia; this is explicable by reduced moisture transport caused by prevailing westerlies during retreat of the Neotethys Ocean. These climatic changes were related to the changing regional plate configuration as well as to global cooling and ice-sheet growth in Antarctica. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.