%0 Journal Article
%T Early Cenozoic Multiple Thrust in the Tibetan Plateau
%A Zhenhan Wu
%A Peisheng Ye
%A Patrick J. Barosh
%A Daogong Hu
%A Lu Lu
%J Journal of Geological Research
%D 2013
%I Hindawi Publishing Corporation
%R 10.1155/2013/784361
%X Recently completed regional geological mapping at a scale of 1£¿:£¿250,000 or larger across all of the Tibetan Plateau coupled with deep seismic surveys reveals for the first time a comprehensive depiction of the major early Cenozoic thrust systems resulting from the northward subduction of the Indian Continental Plate. These systems define a series of overlapping north-dipping thrust sheets that thickened the Tibetan crust and lead to the rise of the plateau. The few south-dipping thrusts present apparently developed within a sheet when the back moved faster than the toe. Many of the thrusts are shown to extend to the middle-lower crustal depths by seismic data. The regional thrust systems are the Main Central, Renbu-Zedong, Gangdese, Central Gangdese, North Gangdese, Bangoin-Nujiang, Qiangtang, Hohxil, and South Kunlun Thrusts. The minimal southward displacements of the South Kunlun, Hohxil, South Qiangtang, and Central Gangdese Thrusts are estimated to be 30£¿km, 25£¿km, 150£¿km and 50£¿km, respectively. Deep thrusting began in the Himalaya-Tibetan region soon after India-Eurasia continental collision and led to crustal thickening and subsequent uplift of the Tibetan Plateau during Late Eocene-Early Miocene when the systems were mainly active. The major thrust systems ceased moving in Early Miocene and many were soon covered by lacustrine strata. This activity succeeded in the late Cenozoic to crustal extension and strike-slip movement in the central Tibetan Plateau. The revelation of the full array of the early Cenozoic thrust systems provides a much more complete understanding of the tectonic framework of the Tibetan Plateau. 1. Introduction A great change in landforms and environments took place during the Cenozoic era as the Indian Continental Plate was subducted northward beneath central Asia to cause crustal thickening and uplift of the Tibetan Plateau. The Tethys Ocean had occupied the Himalayan and southern Tibetan areas at a time when volcanic rocks of the Linzizong Group formed in the Paleocene-Early Eocene magmatic belt along the Gangdese island arc, while the oceanic plate plunged northward along the Yarlung Zangbo suture [1, 2]. Continental red-beds of Fenghuoshan Group were being deposited farther north in central and northern Tibet in Late Cretaceous-Early Cenozoic, and a sea existed beyond Tibet in southwestern Tarim basin [3] (Figure 1). The subduction of the oceanic plate, volcanic eruptions, and intrusions, which ended before ~45£¿Ma, was followed by the subduction of the Indian Continental Plate [4] and the subsequent contractional
%U http://www.hindawi.com/journals/jgr/2013/784361/