鄂尔多斯地块周缘垂直形变场负位错反演与应变积累研究

Strain Accumulation and Inversion of Negative Dislocation for Vertical Deformation Field at the Surroundings of Ordos Block

利用鄂尔多斯地块及其周缘1970~2014年的垂直形变速率场资料,借助负位错反演研究该区域长期应变积累。结果表明,地块东北缘山西断陷带中北段年均能量积累增量、剪应力强度都较高,西南缘六盘山断裂与渭河断裂西段次之;山西断陷带中南段至晋陕交界处年均剪应力强度较高且显示一定程度的能量积累;西秦岭构造区尤其西秦岭北缘断裂西段、晋冀蒙交界区也反映一定程度的能量积累特性。

Using the rate data of vertical deformation field from 1970 to 2014 at the surroundings of Ordos block,with the help of negative dislocation inversion,we study the long-term strain accumulation.The results show that,the first average annual growth rate of energy accumulation and shear stress is the middle-northern segment of Shanxi fault belt at the northeastern margin of Ordos block,the second is the Liupanshan fracture and the western segment of Weihe fracture at the southwestern margin of Ordos block.The segments with high shear stress and relatively lower energy accumulation are the middle-southern segment of Shanxi fault belt and the border between Shanxi and Shaanxi.The western Qinling mountains tectonic area,especially the western segment of the northern margin fault of the west Qinling mountains,and the border area between Shanxi,Hebei and Inner Mongolia,also reflect the characteristics of energy accumulation.