Portal de Periódicos da CAPES

Oceanic plateau subduction during closure of the Bangong-Nujiang Tethyan Ocean: Insights from central Tibetan volcanic rocks

2018; Geological Society of America; Volume: 131; Issue: 5-6 Linguagem: Inglês

10.1130/b32045.1

1943-2674

Lu‐Lu Hao, Qiang Wang, Chunfu Zhang, Quan Ou, Jin‐Hui Yang, Wei Dan, Zi‐Qi Jiang,

Geological and Geophysical Studies

Research Article| November 29, 2018 Oceanic plateau subduction during closure of the Bangong-Nujiang Tethyan Ocean: Insights from central Tibetan volcanic rocks Lu-Lu Hao; Lu-Lu Hao 1State Key Laboratory of Isotope Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China2University of Chinese Academy of Sciences, Beijing 10069, China Search for other works by this author on: GSW Google Scholar Qiang Wang; Qiang Wang † 1State Key Laboratory of Isotope Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China2University of Chinese Academy of Sciences, Beijing 10069, China3Chinese Academy of Science Center for Excellence in Tibetan Plateau Earth Sciences, Beijing 100101, China †Corresponding author: State Key Laboratory of Isotope Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China; wqiang@gig.ac.cn. Search for other works by this author on: GSW Google Scholar Chunfu Zhang; Chunfu Zhang 4Department of Geosciences, Fort Hays State University, Hays, Kansas 67601-4099, USA Search for other works by this author on: GSW Google Scholar Quan Ou; Quan Ou 1State Key Laboratory of Isotope Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China2University of Chinese Academy of Sciences, Beijing 10069, China Search for other works by this author on: GSW Google Scholar Jin-Hui Yang; Jin-Hui Yang 5Institute of Geology and Geophysics, Chinese Academy of Science, Beijing 100029, China Search for other works by this author on: GSW Google Scholar Wei Dan; Wei Dan 1State Key Laboratory of Isotope Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China3Chinese Academy of Science Center for Excellence in Tibetan Plateau Earth Sciences, Beijing 100101, China Search for other works by this author on: GSW Google Scholar Zi-Qi Jiang Zi-Qi Jiang 6School of Earth Science, Guilin University of Technology, Guilin 541004, China Search for other works by this author on: GSW Google Scholar Author and Article Information Lu-Lu Hao 1State Key Laboratory of Isotope Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China2University of Chinese Academy of Sciences, Beijing 10069, China Qiang Wang † 1State Key Laboratory of Isotope Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China2University of Chinese Academy of Sciences, Beijing 10069, China3Chinese Academy of Science Center for Excellence in Tibetan Plateau Earth Sciences, Beijing 100101, China Chunfu Zhang 4Department of Geosciences, Fort Hays State University, Hays, Kansas 67601-4099, USA Quan Ou 1State Key Laboratory of Isotope Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China2University of Chinese Academy of Sciences, Beijing 10069, China Jin-Hui Yang 5Institute of Geology and Geophysics, Chinese Academy of Science, Beijing 100029, China Wei Dan 1State Key Laboratory of Isotope Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China3Chinese Academy of Science Center for Excellence in Tibetan Plateau Earth Sciences, Beijing 100101, China Zi-Qi Jiang 6School of Earth Science, Guilin University of Technology, Guilin 541004, China †Corresponding author: State Key Laboratory of Isotope Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China; wqiang@gig.ac.cn. Publisher: Geological Society of America Received: 03 Mar 2018 Revision Received: 08 May 2018 Accepted: 23 Aug 2018 First Online: 29 Nov 2018 Online Issn: 1943-2674 Print Issn: 0016-7606 © 2018 Geological Society of America GSA Bulletin (2019) 131 (5-6): 864–880. https://doi.org/10.1130/B32045.1 Article history Received: 03 Mar 2018 Revision Received: 08 May 2018 Accepted: 23 Aug 2018 First Online: 29 Nov 2018 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation Lu-Lu Hao, Qiang Wang, Chunfu Zhang, Quan Ou, Jin-Hui Yang, Wei Dan, Zi-Qi Jiang; Oceanic plateau subduction during closure of the Bangong-Nujiang Tethyan Ocean: Insights from central Tibetan volcanic rocks. GSA Bulletin 2018;; 131 (5-6): 864–880. doi: https://doi.org/10.1130/B32045.1 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 Identification of arc magmatic rock associations in a subduction zone has important implications for specifically revealing the geodynamic evolution of the subduction system. The closure time of the Bangong-Nujiang Tethyan Ocean and the detailed subduction processes have been hotly debated, hindering our understanding of the tectonic evolution of central Tibet. Here, we investigated the ca. 110–104 Ma Gerze lavas (basalts, basaltic andesites, andesites, dacites, and rhyolites) in southern Qiangtang. Fusion of slab fluid-metasomatized mantle wedge could yield the basalts, and such basaltic magmas, if contaminated with ancient basement orthogneisses, could have formed the andesites. The basaltic andesites with high Nb and Nb/La are similar to the Nb-enriched arc basalts and probably originated from slab melt-metasomatized mantle. The dacites were generated by fractional crystallization of the subducted mélange-derived intermediate magmas. The rhyolites have geochemical characteristics (high SiO2 and La/Yb; low MgO and Sr/Y) similar to those of Jamaican-type adakites and were possibly sourced from the subducted oceanic plateau at low pressures. The Gerze Jamaican-type adakites and Nb-enriched basalt association could imply intense slab-mantle interactions. The Gerze lava suites show clear arc affinities, indicating that oceanic subduction may have lasted until 100 Ma. Based on previous studies and a noticeable ca. 145–125 Ma magmatic lull in southern Qiangtang, we suggest that the Bangong-Nujiang oceanic subduction geodynamics involved normal subduction (170–145 Ma), flat subduction (145–125 Ma), and slab roll-back (125–101 Ma). Moreover, the flat subduction was most likely caused by subduction of the oceanic plateau. Therefore, we propose, for the first time, that Tethyan oceanic plateau subduction during the Early Cretaceous could explain the tectonic evolution of the Bangong-Nujiang Ocean and distinctive magmatism in southern Qiangtang, central Tibet. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.