Study Of The Northeastern Margin Of Qinghai-tibet Block Crustal Movement Monitoring And Dynamic Mechanism

The northeastern margin of Qinghai-Tibet block is an important tectonic deformation and large earthquake activity region of China. In this paper, three questions have been studied: 1. On the basis of two years'GPS observation of Crustal Movement Observation Network of China (CMONOC) project in this area ( 1999&2001) , GAMIT/GLOBK GPS analysis software was used for data processing and achieved the GPS movement velocity field in northeastern margin of Qinghai-Tibet block; 2. This paper have analysed the data of leveling in recent 30 years in this area; 3. Discussion on crustal dynamics of the northeastern Qinghai-Tibet block. The results show that:1) The western part of Gansu-Qinghai block mainly manifests itself northeastward notion and crustal shortening, the movement of 8mm/a of southern margin of Qaidam basin is nearly completely absorbed by the compressed subsidence of Qaidam basin and compressed uplift of Qilian mountain;2) In the east to Qaidam basin ,the middle and eastern part of the Gansu-Qinghai block rotates clock-wisely as a whole rigid body ;3) Acted by Gansu-Qinghai rotating block at the NW Liupanshan range, the Erdos block takes anti-clockwise rotation;4) The vertical deformation feature of northeastern margin of Qinghai-Tibet block is a returns of the mountain go up, the basin go down and the mountain go down, the basin go up;5) The reason of crustal deformation of northeastern margin of Qinghai-Tibet block is the collision and northward penetration of India block into Eurasia, which result in the northeastern motion of Qinghai-Tibet block.