THE STRUCTURE OF CRUST AND UPPER MANTLE AND FORMATION OF HUGE THICK CRUST IN QINGHAI-XIZANG PLATEAU, CHINA
TENG Jiwen(Institute of Geophysics, Academia Sinica, Beijing 100101)
This paper, on the basis of the explosion seismological data in Qinghai-Xizang Plateau, carries out analysis and calculation. These data are obtained from the profiles of south part of Yarlung Zangbo River, north part of Yarlung Zangbo River (length nearly 1000km) and profile of nearly NS strike (length nearly 1200kin). The author sets up the three-dimentional comprehensive section of structure of crust and upper mantle at Qinghai-Xizang Plateau, and finds that there exist two low-velocity layers in crust. The Yarlung Zangbo River is a steep deep-seated fracture dipping to the south. It should be pointed out that the structure of crust is laterally and longitudinally heterogenous. Finally, it can be put forward that the Himalayan zone is a transition zone between the collided plates, Indian plate and Eurasian plate. The formation of huge thick crust was discussed.