HR: 1340h
AN: T23C-0568    [Abstracts]
TI: Northeastward Growth and Uplift of the Tibetan Plateau: Tectonic-Sedimentary Evolution Insights from Cenozoic Hoh Xil, Qaidam and Hexi Corridor Basins
AU: * Wang, C
EM: chshwang@cugb.edu.cn
AF: Tibetan Plateau Geology Research Center, China University of Geoscience, 29 Xueyuan Road, Beijing, 100083 China
AU: Liu, Z
EM: lzhifei@mail.tongji.edu.cn
AF: State Key Laboratory of Marine Geology, Tongji University, 1239 Siping Road, Shanghai, 200092 China
AU: Zhu, L
EM: zhuld33@sohu.com
AF: School of Earch Scineces, Chengdu University of Technology, 1 Dongsan Road, Erxianqiao, Chengdu, 610059 China
AB: The northeastward growth of the Tibetan Plateau was addressed as a major uplift process of Northeast Tibet. But sedimentary basins in central Tibet still remain less studied. From the Hoh Xil Basin in central Tibet northeastwards to the Qaidam Basin in Northeast Tibet, and to the Hexi Corridor Basin at the northeast edge of Tibet, the Tibetan Plateau consists mainly of the basin-ridge tectonic- sedimentary system, i.e. the Hoh Xil, Qaidam, and Hexi Corridor basins with the Kunlun and Qilian ranges between them. The Hoh Xil Basin provides an amount of 5823 m thick Cenozoic sediments, which were paleomagnetically dated as the Eocene-Early Oligocene (51.0-31.3 Ma) Fenghuoshan Group below, the Early Oligocene (31.3-30.1 Ma) Yaxicuo Group above, with the Early Miocene Wudaoliang on the top. The Qaidam Basin is situated between the Kunlun range in the south and the Qilian range in the north, with an amount of >15000 m thick Cenozoic sediments. Following previous studies, we reconstruct the tectonic-sedimentary history as: the extensional basin stage (65-46 Ma), the foreland basin stage (46- 2.45 Ma), and the intermontane basin stage (2.45-0 Ma). The Hexi Corridor Basin was formed under the Altyn Tagh Fault activity as a strike-slip basin started from 37.7 Ma. The three Cenozoic sedimentary basins have a similar tectonic-sedimentary history, i.e. first as strike-slip/extensional basin, then as foreland basin, and last as intermontane basin. The evolution of their foreland basin stage indicates a northeastward shift of the orogenic uplift: from 47.0-30.1 Ma in central Tibet, to 46-2.45 Ma in Northeast Tibet, and to 30.3-0.13 Ma in the northeast edge of Tibet. At the same time, the each basin depocenter with predominant northeastward paleocurrents also shift northeastwards. The tectonic- sedimentary evolution of the series of Cenozoic sedimentary basin strongly suggests the northeastward growth and uplift process of the Tibetan Plateau started from Eocene to present.
DE: 1625 Geomorphology and weathering (0790, 1824, 1825, 1826, 1886)
DE: 5415 Erosion and weathering
DE: 5475 Tectonics (8149)
DE: 8169 Sedimentary basin processes
DE: 8175 Tectonics and landscape evolution
SC: Tectonophysics [T]
MN: Fall Meeting 2005