Physical structure features of the crust at southeast region of Tibetan Plateau

Abstract

Research results show the obvious differences between the crustal deep physical features of each block and fault zone, and obvious inhomogeneity in longitudinal and horizontal directions. The Gandise block is especially outstanding. Squeezed by Indian Continent, the high conductive layer inclines northward, which is continuous in the Gandise block, but becomes horizontal in distribution and thick in Qiangtang and Bayan Har blocks. The Jinshajiang fault zone inclines northward near Yushu, while Lancangjiang and Nujiang fault zones present vertical distributions. Gravity Bouguer anomalies are high at the south and north edges and low in the center of the plateau. The Zayu-Shama region has not reached gravity equilibrium yet and represents obvious negative anomaly, which indicates that the region is in rapid uplift. Its geomagnetic anomaly varies evidently in different blocks and on different fault zones, and decreases obviously both in intensity and amplitude variations from south to north. The surveys and researches of various geophysical methods reflect the spatial distribution features of the blocks and faults in the surveyed area.