Abstract:
Abstract: The last-phase and strongest uplift of the Qinghai-Tibet plateau occurred at 1-0.8Ma BP, which was related to the Australasian meteorite impact event in the triple junction of the Indian Ocean ridge. The impact event resulted in rapid spreading of the Indian Ocean ridge and strong A-subduction of the Indian plate beneath the Siwalik. The strong subduction gave rise to the rapid uplift of the Qinghai-Tibet Plateau and its surrounding mountains, thus forming the basin-range geomorphology in western China. The eastern Kunlun Mountains were elevated approximately 3000 m by the thrust system and meanwhile moved ~ 400km to the north, which should be responsible for the Cenozoic deformation in the Qaidam basin and Hexi corridor. Therefore, this impact event can interpret the last phase of the uplift of the Qinghai-Tibet Plateau and geodynamic background of the formation of continental tectonics of western China. 40Ar/39Ar dating of neogenic minerals during deformation suggests that the strike-slip movement of the Altun (Altyn) fault may have started at 97-89Ma, occurring nearly synchronously with the formation of the "Western tectonic node" in the Nepal-western Kunlun area The Altun strike-slip fault has a cumulative offset of 350-400km and displaced the original tectonic belts and basins in the Late Cretaceous-Cenozoic, which provides a new idea for mineral, oil and natural gas searching in western China.