利用GPS数据探讨鄂尔多斯地块南缘地壳形变特征

Deformation Characteristics Investigation in the Southern Margin of Ordos Block Based on GPS Data

利用2010～2012年GPS水平运动速度场数据,计算并探讨了鄂尔多斯地块南缘地区的面膨胀率、主应变率、最大剪应变率等应变场变化特征,初步获得了3点结论:(1)鄂尔多斯地块南缘的关中盆地内部显示了显著的面压缩特性,平均压应变率约-4. 0×10^(-8)/a,而在盆地北部鄂尔多斯地块内边缘及盆地以南的秦岭区域则表现为面膨胀特征;(2)关中盆地内部主应变率变化幅度较小,但盆地周边主应变强度较大;(3)当地壳断裂走向与GPS水平运动矢量方向接近时,可能会出现最大剪应变高值区。

In this article,we used GPS velocity field data from 2010 to 2012 calculated and analyzed the surface expansion rate,principal strain rate,maximum shear strain rate about southern margin of Ordos block.We got three conclusions preliminary:①the Guanzhong Basin internal with on the southern of Erdos block shows significant compression characteristics,the average compressive strain rate is about-4.0×10^-8/a,but the edges in the northern basin and Qinling Mountains area are performance of surface expansion characteristics.②The main strain rate changes slightly inside of the Guanzhong Basin,but the main strain intensity is strike around the basin.③When the trend of crustal fracture is close to that of GPS horizontal motion vector,the maximum shear strain high value area may occur.