摘要
中国地壳运动观测网络工程等GPS观测结果表明 ,相对于稳定的阿拉善地块 ,青藏块体东北缘及其邻区现今地壳运动具有如下特征 :①甘青块体西部以北东向挤压运动和地壳缩短为主 ,其中柴达木盆地南缘 8mm/a的北东向地壳运动几乎全为柴达木盆地的压陷沉降和祁连山地的上升缩短所吸收 ;②柴达木盆地以东的甘青块体中、东部表现为整体的顺时针刚性旋转运动 ,其旋转北边界为毛毛山—海原走滑断裂带 ,旋转角速率为 0 .135°/Ma ;③受甘青块体顺时针旋转运动的耦合影响 ,鄂尔多斯地块表现为逆时针旋转运动 ,两者的耦合边界为北西向的六盘山断裂带 ;④海原左旋走滑断裂带和祁连北缘逆冲断裂带构成了青藏块体东北缘现今地壳运动的主边界。
GPS observations of CMONOC reveal that,relative to the stable Alashan block,the crustal movements of north eastern margin of Qinghai Tibet block and its adjacent region mainly display the following characteristics:(1)the western part of Gansu Qinghai block mianly manifests itself northeastward motion and crustal shortening,the movement of 8 mm/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 with angular velocity of 0.135° degree/Ma,the northern boundary of the rotating block is Haiyuan fault;(3)Acted by Gansu Qinghai rotating block at the NW Liupanshan range,the Erdos block takes anti clockwise rotation;(4)Haiyuan left lateral active fault and northern edge thrust fault of Qilian moutain compose the major northeastern boundary of present day crustal movement of the Qinghai Tibet block.
出处
《大地测量与地球动力学》
CSCD
2002年第4期12-16,共5页
Journal of Geodesy and Geodynamics
基金
国家 973项目<大陆强震机理与预测>子课题 (G19980 40 70 3 )
