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Xigaze forearc basin revisited (South Tibet): Provenance changes and origin of the Xigaze Ophiolite

2014; Geological Society of America; Volume: 126; Issue: 11-12 Linguagem: Inglês

10.1130/b31020.1

1943-2674

Wei An, Xiumian Hu, Eduardo Garzanti, Marcelle K. BouDagher‐Fadel, Jian‐Gang Wang, Gaoyuan Sun,

High-pressure geophysics and materials

Research Article| November 01, 2014 Xigaze forearc basin revisited (South Tibet): Provenance changes and origin of the Xigaze Ophiolite Wei An; Wei An 1State Key Laboratory of Mineral Deposits Research, School of Earth Sciences and Engineering, Nanjing University, Nanjing, 210029, 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, Nanjing, 210029, China †E-mail: huxm@nju.edu.cn. Search for other works by this author on: GSW Google Scholar Eduardo Garzanti; Eduardo Garzanti 2Department of Earth and Environmental Sciences, Università di Milano-Bicocca, Milano, 20126, Italy 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, WC1E 6BT, UK Search for other works by this author on: GSW Google Scholar Jiangang Wang; Jiangang Wang 4Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing, 100029, China Search for other works by this author on: GSW Google Scholar Gaoyuan Sun Gaoyuan Sun 1State Key Laboratory of Mineral Deposits Research, School of Earth Sciences and Engineering, Nanjing University, Nanjing, 210029, China Search for other works by this author on: GSW Google Scholar Author and Article Information Wei An 1State Key Laboratory of Mineral Deposits Research, School of Earth Sciences and Engineering, Nanjing University, Nanjing, 210029, China Xiumian Hu † 1State Key Laboratory of Mineral Deposits Research, School of Earth Sciences and Engineering, Nanjing University, Nanjing, 210029, China Eduardo Garzanti 2Department of Earth and Environmental Sciences, Università di Milano-Bicocca, Milano, 20126, Italy Marcelle K. BouDagher-Fadel 3Department of Earth Sciences, University College London, London, WC1E 6BT, UK Jiangang Wang 4Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing, 100029, China Gaoyuan Sun 1State Key Laboratory of Mineral Deposits Research, School of Earth Sciences and Engineering, Nanjing University, Nanjing, 210029, China †E-mail: huxm@nju.edu.cn. Publisher: Geological Society of America Received: 22 Oct 2013 Revision Received: 18 Apr 2014 Accepted: 16 May 2014 First Online: 08 Mar 2017 Online ISSN: 1943-2674 Print ISSN: 0016-7606 © 2014 Geological Society of America GSA Bulletin (2014) 126 (11-12): 1595–1613. https://doi.org/10.1130/B31020.1 Article history Received: 22 Oct 2013 Revision Received: 18 Apr 2014 Accepted: 16 May 2014 First Online: 08 Mar 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn Email Permissions Search Site Citation Wei An, Xiumian Hu, Eduardo Garzanti, Marcelle K. BouDagher-Fadel, Jiangang Wang, Gaoyuan Sun; Xigaze forearc basin revisited (South Tibet): Provenance changes and origin of the Xigaze Ophiolite. GSA Bulletin 2014;; 126 (11-12): 1595–1613. doi: https://doi.org/10.1130/B31020.1 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 Our new stratigraphic, sedimentological, and micropaleontological analysis, integrated with basalt geochemistry, sandstone petrography, and detrital-zircon U-Pb and Hf isotope data, suggests the revision of current models for the geological evolution of the Asian active margin during the Cretaceous. The Xigaze forearc basin began to form in the late Early Cretaceous, south of the Gangdese arc, during the initial subduction of the Neotethyan oceanic lithosphere under the Lhasa terrane. Well-preserved stratigraphic successions document the classical upward-shallowing pattern of the forearc-basin strata and elucidate the origin of the associated oceanic magmatic rocks. The normal mid-ocean-ridge basalt (N-MORB) geochemical signature and stratigraphic contact with the overlying abyssal cherts (Chongdui Formation) indicate that the Xigaze Ophiolite formed by forearc spreading and represents the basement of the forearc sedimentary sequence. Volcaniclastic sedimentation began with thick turbiditic sandstones and interbedded shales in the late Albian–Santonian (Ngamring Formation) followed by shelfal, deltaic, and fluvial strata (Padana Formation), with final filling of the basin by the Campanian age. Forearc sandstones do not show the classical trend from feldspatho-lithic volcaniclastic to quartzo-feldspathic plutoniclastic compositions, indicating limited unroofing of the Gangdese arc prior to collision. U-Pb age spectra of detrital zircons are unimodal with a 107 Ma peak in the lower Ngamring Formation (104–99 Ma), bimodal with a subordinate additional peak at 157 Ma in the middle Ngamring Formation (99–88 Ma), and multimodal with more abundant pre-Mesozoic ages in the upper Ngamring and Padana Formations (88–76 Ma). These three petrofacies with distinct provenances document the progressive erosional evolution of the Gangdese arc, with uplift of the central Lhasa terrane and expanding river catchments to include the central Lhasa terrane during the Late Cretaceous. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.