Identification of tectonic units within Lhasa terrane in western Tibet by velocity structure along Hi-Climb and its indication for the evolution of the Tibetan Plateau
The northward collision and subduction of the Indian continental plate have led to the rapid uplift of the Tibetan Plateau. During the uplift process,the material composition and tectonic evolution are highly complicated in the plateau,and the distribution characteristics and tectonic origin of the low-velocity layer within the plateau are not clear. In this paper,we collected data from the northern stations of the Hi-Climb and used the receiver function complex spectral ratio-based nonlinear inversion method to obtain 1-D shear velocity structure. Combining previous geophysical research results,our result show that the shear-wave low-velocity layer in the lower crust beneath the profile is separated by the Shiquanhe-Namco Melange suture zone (SNMZ) and the Bangong-Nujiang suture zone (BNS),and distinctly differ from each other. This result indicates that the SNMZ is a deep fault zone between the Central and North Lhasa terranes,and also an important transition zone at the uppermost mantle. Low-velocity layer in the upper crust is mainly related to the surface geological structure and the distribution of sedimentary layers. Horizontal distribution of the low velocity layer in the middle and lower crust is not only constrained by terrane boundaries,such as SNMZ and BNS,but also related to the uplift of the Tibetan Plateau.
Tibetan Plateaureceiver function analysisShiquanhe-Namco Melange suture zonelow velocity zoneLhasa terrane
万方数据
维普
