Eastward migration of the Qaidam basin and its implications for Cenozoic evolution of the Altyn Tagh fault and associated river systems

Research Article| March 01, 2006 Eastward migration of the Qaidam basin and its implications for Cenozoic evolution of the Altyn Tagh fault and associated river systems Erchie Wang; Erchie Wang 1Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing 100029, People's Republic of China and Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing 100029, People's Republic of China Search for other works by this author on: GSW Google Scholar Feng-Yin Xu; Feng-Yin Xu 2Qinghai Petroleum Sub-corporation of PetroChina Company Limited, Dunhuang 736202, People's Republic of China Search for other works by this author on: GSW Google Scholar Jian-Xun Zhou; Jian-Xun Zhou 3Earth Science Department, University of Petroleum, Beijing 102249, People's Republic of China Search for other works by this author on: GSW Google Scholar Jinglin Wan; Jinglin Wan 4Laboratory of Neotectonic Chronology of Institute of Geology, China Seismological Bureau, Beijing 100029, People's Republic of China Search for other works by this author on: GSW Google Scholar B. Clark Burchfiel B. Clark Burchfiel 5Department of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA Search for other works by this author on: GSW Google Scholar GSA Bulletin (2006) 118 (3-4): 349–365. https://doi.org/10.1130/B25778.1 Article history received: 14 Dec 2004 rev-recd: 27 Aug 2005 accepted: 01 Sep 2005 first online: 08 Mar 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation Erchie Wang, Feng-Yin Xu, Jian-Xun Zhou, Jinglin Wan, B. Clark Burchfiel; Eastward migration of the Qaidam basin and its implications for Cenozoic evolution of the Altyn Tagh fault and associated river systems. GSA Bulletin 2006;; 118 (3-4): 349–365. doi: https://doi.org/10.1130/B25778.1 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 SocietyGSA Bulletin Search Advanced Search Abstract The Qaidam basin is the largest Cenozoic intermontane basin within the Tibetan plateau, bounded by the Qilian Shan range to the north, the East Kunlun range to the south, the Altyn Tagh range to the west, and the Ela Shan range to the east. Its deposits consist of nonmarine sedimentary rocks, with a maximum thickness exceeding 13,400 m. Modern sedimentation mainly takes place along the marginal areas of the basin, where alluvial fans are formed along a series of rivers that originate from the surrounding mountains. Nevertheless, drilling, sedimentary, and seismic data reveal that the depocenter of the basin during much of Cenozoic time was not developed as foreland basins of the Qilian Shan belt to the north and the East Kunlun belt to the south, but instead the depocenter was in the center of the western part of the basin and had a northwest-southeast trend that shifted eastward ∼380 km during Oligocene to Quaternary time. This indicates that most of the basin sediments were not derived from the surrounding mountain ranges. The results of the fission-track age dating reveal that the rapid uplift of the Yousha Shan anticline bounding the depocenter to the southwest initiated at ca. 31 Ma, indicating that the southeastward shift of the depocenter began at that time, yielding a migration rate for the depocenter of 10.2 mm/yr. The northwestern margin of the depocenter of the Qaidam basin lies to the east of the westward prolongation of the Qaidam basin, the Tula trough, a 300-km-long narrow trough flanked by the Altyn Tagh range along the Altyn Tagh strike-slip fault on the north and the East Kunlun thrust belt on the south. The sedimentary and deformational evidence from this region indicates that the Tula trough was formed as a syncline, along which a paleoriver flowed to the east into the Qaidam basin. To the southwest, this river valley merges with the trace of the Altyn Tagh fault. The latter and its westward continuation are interpreted to have extended to the northern margin of the Pamir folded belt north of the western syntaxis of the Himalaya. We propose that most of the sediments within the depocenter of the Qaidam basin were transported from the northern margin of the Pamir folded belt along a progressively lengthening 2000-km-long longitudinal river that developed along the left-lateral Altyn Tagh fault and its western continuation, as the eastward extrusion of the Tibetan plateau took place in Oligocene time. Both the crustal uplift and continuous southeastward aggradations of the sediments carried by the paleo–Kunlun River are interpreted to be the cause for southeastward migration of the depocenter of the Qaidam basin. The longitudinal river disappeared in late Cenozoic time (2–4 Ma) due to stream capture and climate change. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.