Role of the Early Miocene Jinhe-Qinghe Thrust Belt in the building of the Southeastern Tibetan Plateau topography

Autor: Yue Chen, Pan Zhang, Chengyu Zhu, Philippe Hervé Leloup, Kai Cao, Guiling Wu, Bo Wu, Paul Sotiriou, Gweltaz Mahéo, Tianyi Shen, Guocan Wang
Přispěvatelé: China University of Geosciences [Wuhan] (CUG), Laboratoire de Géologie de Lyon - Terre, Planètes, Environnement (LGL-TPE), École normale supérieure de Lyon (ENS de Lyon)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut national des sciences de l'Univers (INSU - CNRS)-Université Jean Monnet - Saint-Étienne (UJM)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Géologie de Lyon - Terre, Planètes, Environnement [Lyon] (LGL-TPE), École normale supérieure - Lyon (ENS Lyon)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)
Jazyk: angličtina
Rok vydání: 2021
Předmět:
Zdroj: Tectonophysics
Tectonophysics, 2021, 811, ⟨10.1016/j.tecto.2021.228871⟩
Tectonophysics, Elsevier, 2021, 811, ⟨10.1016/j.tecto.2021.228871⟩
ISSN: 0040-1951
1879-3266
DOI: 10.1016/j.tecto.2021.228871⟩
Popis: International audience; Understanding the role of southeastern Tibetan thrust faults in the development of plateau topography is key to our assessment of the geodynamic processes shaping continental topography. Detailed structural analysis along the ~400 km long Jinhe-Qinghe thrust belt (JQTB) indicates post Late Eocene thrust motion with a minor leftlateral component, inducing ~0.6 to 3.6 km of apparent vertical offset across the fault. The exhumation history of the Baishagou granite, based on thermal modeling of new apatite (U-Th)/He and fission-track results, suggests an accelerated exhumation rate (~0.4 km/Myr) between 20 and 16 Ma, corresponding to ~1.7-2.4 km of exhumation. We interpret this fast exhumation as a manifestation of the activation of the Nibi thrust, a northern branch of the JQTB, resulting in the creation of significant relief across the JQTB in the Early Miocene. When compared with previous studies, our findings show that Cenozoic exhumation and relief creation in southeastern Tibet cannot be explained by a single mechanism. Rather, at least three stages of relief creation should be invoked. The first phase is Eocene NE-SW compression partly coeval with Eocene sedimentation. During the Late Oligocene to Early Miocene and coeval with the extrusion of Indochina, the second thrusting phase occurred along the Yulong and Longmenshan thrust belts, and then migrated to the JQTB at 20-16 Ma. The third phase involved the activation of the Xianshuihe fault and the re-activation of the Longmenshan thrust belt and the Muli thrust. Uplift in the hanging wall of thrust belts appears to explain most of the present-day relief in the southeastern Tibetan Plateau.
Databáze: OpenAIRE
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