BIROn - Birkbeck Institutional Research Online

    Drainage evolution and exhumation history of the eastern Himalaya: Insights from the Nicobar Fan, northeastern Indian Ocean

    Chen, W.-H. and Yan, Y. and Clift, P. and Carter, Andrew and Huang, C.-Y. and Pickering, K. and Chemale, F. and Shan, Y. and Zhang, X. (2020) Drainage evolution and exhumation history of the eastern Himalaya: Insights from the Nicobar Fan, northeastern Indian Ocean. Earth and Planetary Science Letters 548 , ISSN 0012-821X.

    This is the latest version of this item.

    [img]
    Preview
    Text
    Chen Final.pdf - Author's Accepted Manuscript
    Available under License Creative Commons Attribution Non-commercial No Derivatives.

    Download (1MB) | Preview

    Abstract

    The eastern Himalayan syntaxis, where the Yarlung Tsangpo sharply bends, is one of the areas experiencing most rapid exhumation on Earth. The rapid exhumation is often regarded as the result of capture of the Yarlung Tsangpo by the Brahmaputra River. However, both the timing of integration of the Yarlung Tsangpo-Brahmaputra River and initiation of the rapid syntaxial exhumation are debated. As the ultimate sedimentary trap of the Yarlung Tsangpo-Brahmaputra River, the Nicobar Fan is a window to look into the drainage evolution and exhumation history of the eastern Himalaya. International Ocean Discovery Program Expedition 362 drilled the Nicobar Fan for the first time, recovering fan sediments dating back to the Early Miocene (∼19Ma). We apply trace elements and Sr-Nd isotopes to investigate the provenance of the sediments in the Nicobar Fan with the aim of constraining the timing of integration of the Yarlung Tsangpo-Brahmaputra River and initiation of the rapid syntaxial exhumation. The geochemical and Sr-Nd isotope compositions indicate an eastern Himalayan source dominated by the Greater Himalaya, with significant Gangdese arc contribution and primarily carried by the Brahmaputra River. Flux of Gangdese arc material appears to have been continuous from the base of the Nicobar Fan, suggesting that the Yarlung Tsangpo-Brahmaputra River has been established at least since ∼19Ma. Synchronously with the sharp rise in sedimentation rate, the abrupt change of geochemical and isotope compositions at ∼9.2Ma indicates an increase in erosion of the Greater Himalaya as the result of initiation of rapid exhumation in the broad syntaxial region. The proportion of Greater Himalayan material increased again at 3.5–1.7Ma, consistent with a younger pulse of rapid exhumation focused in the core of the syntaxis since ∼3.5Ma. Our results show that initiation of the rapid syntaxial exhumation postdated integration of the Yarlung Tsangpo-Brahmaputra River by at least ∼10 m.y. Therefore, tectonic uplift rather than river capture could be responsible for the initiation of the rapid syntaxial exhumation.

    Metadata

    Item Type: Article
    School: Birkbeck Faculties and Schools > Faculty of Science > School of Natural Sciences
    Research Centres and Institutes: Earth and Planetary Sciences, Institute of
    Depositing User: Andy Carter
    Date Deposited: 04 Aug 2020 12:46
    Last Modified: 02 Aug 2023 18:01
    URI: https://eprints.bbk.ac.uk/id/eprint/32771

    Available Versions of this Item

    • Drainage evolution and exhumation history of the eastern Himalaya: Insights from the Nicobar Fan, northeastern Indian Ocean. (deposited 04 Aug 2020 12:46) [Currently Displayed]

    Statistics

    Activity Overview
    6 month trend
    138Downloads
    6 month trend
    123Hits

    Additional statistics are available via IRStats2.

    Archive Staff Only (login required)

    Edit/View Item Edit/View Item