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Late Cretaceous evolution of the Coqen Basin (Lhasa terrane) and implications for early topographic growth on the Tibetan Plateau

2015; Geological Society of America; Linguagem: Inglês

10.1130/b31137.1

1943-2674

Gaoyuan Sun, Xiumian Hu, Hugh D. Sinclair, Marcelle K. BouDagher‐Fadel, Jian‐Gang Wang,

Geological and Geophysical Studies Worldwide

Research Article| July 01, 2015 Late Cretaceous evolution of the Coqen Basin (Lhasa terrane) and implications for early topographic growth on the Tibetan Plateau Gaoyuan Sun; Gaoyuan Sun 1State Key Laboratory of Mineral Deposits Research, School of Earth Sciences and Engineering, Nanjing University, Xianlin Dadao 163, Nanjing, 210023, China Search for other works by this author on: GSW Google Scholar Xiumian Hu; Xiumian Hu † 1State Key Laboratory of Mineral Deposits Research, School of Earth Sciences and Engineering, Nanjing University, Xianlin Dadao 163, Nanjing, 210023, China †E-mail: huxm@nju.edu.cn Search for other works by this author on: GSW Google Scholar Hugh D. Sinclair; Hugh D. Sinclair 2School of GeoSciences, University of Edinburgh, Drummond Street, Edinburgh EH8 9XP, Scotland, UK Search for other works by this author on: GSW Google Scholar Marcelle K. BouDagher-Fadel; Marcelle K. BouDagher-Fadel 3Department of Earth Sciences, University College London, London WC1H 0BT, UK Search for other works by this author on: GSW Google Scholar Jiangang Wang Jiangang Wang 4State Key Laboratory of Lithospheric Evolution, Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing, 100029, China Search for other works by this author on: GSW Google Scholar Author and Article Information Gaoyuan Sun 1State Key Laboratory of Mineral Deposits Research, School of Earth Sciences and Engineering, Nanjing University, Xianlin Dadao 163, Nanjing, 210023, China Xiumian Hu † 1State Key Laboratory of Mineral Deposits Research, School of Earth Sciences and Engineering, Nanjing University, Xianlin Dadao 163, Nanjing, 210023, China Hugh D. Sinclair 2School of GeoSciences, University of Edinburgh, Drummond Street, Edinburgh EH8 9XP, Scotland, UK Marcelle K. BouDagher-Fadel 3Department of Earth Sciences, University College London, London WC1H 0BT, UK Jiangang Wang 4State Key Laboratory of Lithospheric Evolution, Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing, 100029, China †E-mail: huxm@nju.edu.cn Publisher: Geological Society of America Received: 22 May 2014 Revision Received: 09 Dec 2014 Accepted: 15 Jan 2015 First Online: 08 Mar 2017 Online ISSN: 1943-2674 Print ISSN: 0016-7606 © 2015 Geological Society of America GSA Bulletin (2015) 127 (7-8): 1001–1020. https://doi.org/10.1130/B31137.1 Article history Received: 22 May 2014 Revision Received: 09 Dec 2014 Accepted: 15 Jan 2015 First Online: 08 Mar 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn Email Permissions Search Site Citation Gaoyuan Sun, Xiumian Hu, Hugh D. Sinclair, Marcelle K. BouDagher-Fadel, Jiangang Wang; Late Cretaceous evolution of the Coqen Basin (Lhasa terrane) and implications for early topographic growth on the Tibetan Plateau. GSA Bulletin 2015;; 127 (7-8): 1001–1020. doi: https://doi.org/10.1130/B31137.1 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 tectonic evolution of the Lhasa terrane (southern Tibetan Plateau) played a fundamental role in the formation of the Tibetan Plateau. However, many uncertainties remain with regard to the tectonic and paleogeographic evolution of the Lhasa terrane prior to the India-Asia collision. To determine the early tectonic processes that controlled the topographic evolution of the Lhasa terrane, we analyze the Cretaceous strata exposed in the Coqen Basin (northern Lhasa subterrane), which comprises the Langshan and Daxiong Formations. The Langshan Formation unconformably overlies the volcanic rocks of the Lower Cretaceous Zelong Group and consists of ∼80 m of Orbitolina-bearing limestones, which were deposited in a low-energy, shallow marine environment. Micropaleontological analysis indicates that the Langshan Formation in the Coqen Basin was deposited from late Aptian to early Cenomanian times (ca. 113–96 Ma). The overlying Daxiong Formation (∼1700 m thick) consists of conglomerate, coarse sandstone, and siltstone with interbedded mudstone, and represents deposits of alluvial fans and braided rivers. The Daxiong Formation was deposited after the early Cenomanian (ca. 96 Ma) and accumulated until at least ca. 91 Ma, indicating accumulation rates of greater than 0.3 km m.y.–1. By combining paleocurrent data, sandstone petrology, detrital zircon U-Pb ages, and Hf isotope analysis, we demonstrate that the Daxiong Formation was derived from Lower Cretaceous volcanic rocks and pre-Cretaceous strata in the northern Lhasa subterrane. During Late Cretaceous time, two thrust systems with opposite vergence were responsible for transforming the northern Lhasa subterrane into an elevated mountain range. This process resulted in the evolution from a shallow marine environment (Langshan Formation) into a terrestrial depositional environment (Daxiong Formation) on the southern margin of the northern Lhasa subterrane. Given the regional paleogeographic context, we conclude that the Daxiong Formation in the Coqen Basin records local crustal shortening and flexure resulting in foreland basin development on the southern margin of the northern Lhasa subterrane, which implies early topographic growth of the northern Lhasa subterrane in southern Tibet prior to the India-Asia collision. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.