Crustal Structure of China Mainland and its Adjacent Regions

Abstract

According to the three-component teleseismic records from digital seismic network of China mainland and its adjacent regions, the S-wave velocity structure beneath the 61 teleseismic stations were investigated by using the transform function method and the SA techniques. Based on the results of our work and the information from artificial seismic sounding, this paper presents Moho topography of China mainland and its adjacent regions which can serve as credible geophysics evidence for revealing the geodynamic evolution processes and establishing the continental collisional theory. In principle, the crustal thickness of China mainland and adjacent regions increase from east to west, and the crustal structure can be divided into there types, including the smooth belt such as Mongolia plateau, North China, Central China, South China and Qinghai-Tibet plateau; the transform belt such as regions along the Great Xing'an mountains, the Taihang mountains, the Qinling mountains, the Daba mountains and Yungui plateau; and the gradient belt such as Qinghai-Tibet plateau periphery. For the smooth belt, simple S wave velocity structure and clear crustal-mantle boundary are revealed except for Qinghai-Tibet plateau. The S wave velocity structures beneath regions along Taiwan-Philippine Islands, Qinghai-Tibet plateau and its south flank are complex. It indicates that the tectonic movement and substance exchange are active in the plate boundary regions and the crust remains in the state of imbalance.