Research on Recent Crustal Horizontal Movement of Northeastern Margin of Qinghai-Tibet Block Based on GPS

Northeastern margin of Qinghai-Tibet block is an important tectonic movement boundary, and is also a window to research on crustal movement of Qinghai-Tibet Plateau. Through studying the geology structure and tectono-dynamic characteristics of the test area, it is of great significance not only for Qinghai-Tibet Plateau itself, but also for correctly realizing and analyzing present-day tectonic deformation and dynamic mechanism in northwest China. Based on the GPS observation data from 1999 to 2001 and the soft of GAMIT/GLOBK, the horizontal movement rate-field in northeastern margin of Qinghai-Tibet block is obtained, which is relative to the stable Eurasian continent from 1999 to 2001. Combing with the mechanism of tectonic movement and geo- dynamics, we mainly conclude that:①Haiyuan left-lateral active fault and northern edge thrust fault of Qiliang mountain compose the marjor northeastern boundary of present-day crustal movement of Qinghai-Tibet block; ②the west part of Gansu-Qinghai block’crustal movement characteristics is dominated by N-S compression and crustal shortening, and the east part rotates clock-wisely as an integral rigid body;③the Erdos block may take anti-clockwise rotation drived by Gansu-Qinghai rotating block, and the velocity reaches the maximum at the northwest part of Liupan mountain fault.