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Provenance of Tibetan Geoid Ridge and its Implication to the Collision Evolution between India and Tibet
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  • Peilong Yan,
  • Nan Zhang,
  • Xi Liu,
  • Bo Wan
Peilong Yan
Peking University
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Nan Zhang
Peking University

Corresponding Author:[email protected]

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Xi Liu
Institute of Oceanology Chinese Academy of Sciences
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Bo Wan
Institute of Geology and Geophysics, Chinese Academy of Sciences
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Abstract

The geoid minima in the Indian Ocean and North Eurasia are separated by the Tibetan Geoid Ridge (TGR), yet the origin of TGR remains poorly constrained. Spherical harmonic analysis and geoid kernels indicate that the TGR has wavelengths of degrees 7-10 and is generated by density anomalies of degrees 7-10 in the mantle. By employing numerical geoid modelling with four different tomography-derived density structures, we determined that abundant high-density anomalies in the mantle transition zone beneath Tibet are responsible for TGR. Additionally, two previously proposed alternative evolving scenarios of the India-Tibet collision — Indian lithosphere subduction and Tibetan lithosphere dripping — are evaluated through geoid calculation. The former suggests abundant high-density structures in the Tibetan transition zone, which can generate a well-constrained TGR, while the latter does not. Therefore, we regard the Indian lithosphere subduction as a more plausible evolving scenario.
02 Mar 2024Submitted to ESS Open Archive
05 Mar 2024Published in ESS Open Archive