Lithospheric electrical structure in the central Tibetan Plateau and its tectonic significance

Abstract The Himalaya-Tibetan Plateau that is situated in the southwest China is an ideal natural field laboratory for continental dynamics. In this study, through the careful processing and analyzing of the magnetotellurics data, the reliable 2-D electrical model was obtained to examine the relationship between the lithospheric electrical structure and dynamics in the central Himalaya-Tibetan Plateau. Six conductors mainly result from the partial melting and aqueous fluids, and three resistors are related to different tectonic evolution in the model. Combined with other observations, we summarize that the upwelling hot material (partial melting), aqueous fluids, subduction erosion and crushed zone contribute to the error between the electrical location and the geographic location of the Indus-Yarlung Zangbo suture. The subducted Indian plate is shown by the different angles and different locations of its frontier in different areas. The electrical structure beneath the Lhasa terrane corresponds well with the geological features of an old, locally reworked crust dominantly in the central Lhasa terrane with two young juvenile crustal blocks surrounding the central terrane, and it also shows the relationship among the dynamics, magmatism and mineralization in the Gangdise metallogenic belt. Meanwhile, we indicate that the subducted polarity of the Bangong-Nujiang Tethyan Ocean lithosphere was double-sided, and the smooth subduction of the Longmu Tso-Shuanghu Tethyan Ocean lithosphere may cut through the Moho surface approximately 20 km. Above all, these results can provide helpful constrains to understand the evolution mechanism of the Himalaya-Tibetan Plateau.