摘要
利用青藏块体东北缘地区 1 993、1 999年GPS观测资料 ,给出了本区地壳水平运动速度场及视应变场分布图 ,提出了由位移观测值直接求解块体旋转和变形参数的方法 ,初步研究了本区构造块体运动与变形特征 .结果表明 :①本区存在整体性向东—东南方的运动(速率约 9mm/a) ;②南部的甘肃—青海块体的运动较快 ,而北部的阿拉善块体的运动较慢 ,二者运动速率相差近 6mm/a,祁连—海原断裂带左旋走滑运动显著 .③自西向东存在北北东—北东东向压性运动 ;④阿拉善块体、甘肃—青海块体内部存在北西西向张性变形 ,阿拉善块体的整体张性变形更显著 ,鄂尔多斯块体西侧的块体交接地带为压性运动 .
HTThe distribution of velocity field of crustal horizontal movement and apparent strain field in the northeast margin of Qinghai-Xizang block is studied on the basis of GPS data in 1993 and 1999. A method for directly solving the parameters of block rotation and deformation from displacement observation is presented. The characteristics of tectonic motion and deformation in this area are studied preliminarily. The results show that (1) There exists a whole motion toward east-southeast with a velocity of 9mm/a; (2) Gansu-Qinghai block in the south of this area moves faster, while Alashan block in the north of this area moves slower, the difference of the velocity between two blocks is near 6mm/a, the sinistral strike slip movement of Qilian-Haiyuan fracture zone is much more remarkable; (3) There exists NNE-NEE compressional movement from west to east; (4) Inside Alashan block and Gansu-Qinghai block, there exist NWW tensional deformation, the whole tensional deformation of Alashan block is even more obvious. In the meeting region of blocks in the west side of Ordos block, there exists compressional movement. HTH
出处
《地球物理学报》
SCIE
EI
CAS
CSCD
北大核心
2001年第5期636-644,共9页
Chinese Journal of Geophysics
基金
国家重点基础研究发展规划项目 (G1 9980 40 70 3 )
关键词
GPS观测
块体运动
变形
视应变场
青藏块体
地壳运动
HTZK(GPS observational results, Block movement and deformation, Apparent strain field, Qinghai-Xizang block.
