鄂尔多斯周缘地壳应力场研究  

The Crustal Stress Field around the Ordos Block

作　　者：邓山泉 盛书中[1] 

机构地区：[1]防灾科技学院,河北三河065201 [2]中国科学院大学地球科学学院,北京100049

出　　处：《华北地震科学》2015年第2期55-62,共8页North China Earthquake Sciences

基　　金：中国地震局教师基金项目(20140102);中央高校基本科研业务专项资金(创新项目团队资助计划)(ZY20110101)

摘　　要：收集了鄂尔多斯周缘的297个震源机制解数据,应用震源机制解反演应力场的网格搜索法分区反演该地块周缘地区平均应力场。应力场反演结果显示:该地块周缘地区地壳应力场总体表现为NE-SW向的主压应力,NW-SE向的主张应力。北缘的河套活动断陷带处于ENE-WSW向的水平挤压和NNW-SSE向的水平拉张共同作用的应力状态。南缘的渭河断陷带处于近NS向的水平拉张应力状态。东缘的山西断陷盆地带处于NNW-SSE向的水平拉张应力状态。在地块西面,主压应力轴方向由南段的ENE向逐渐向中段逆时针转为近NE向,继而往北转为NNE向。应力场反演结果和鄂尔多斯地块NS两侧呈EW向展布的断陷带表现为左旋剪切拉张带以及EW两侧呈NNE向展布的断陷带则表现为右旋剪切拉张带的性质一致。本研究结果与前人的研究结果一致性较好,说明了结果的可靠性。Based on 297 focal mechanism solutions around the Ordos block,the stress field around the Ordos block was inversed.The inversion result indicates that the principal compression stress direction around the Ordos block is NE-SW and the principal tension stress direction is NW-SE.Hetao active fault subsidence zone,on north edge of the block,are under the joint action of the ENE-WSW horizontal compression and the NNW-SSE horizontal tension stress field.Weihe fault subsidence zone is under the tension of the nearly NS horizontal stress field.Shanxi faulted basin zone is under the tension of the NNW-SSE horizontal stress field.In the west of the Ordos block,the strikes of the principal compression stress axes from south to north,and turn gradually from ENE to NNE direction.Both the Weihe faulted basin zone and Hetao faulted basin zone are nearly EW-trending left-lateral shear zones with extension components,while both the Shanxi faulted basin zone and Yinchuan-Jilantai faulted basin zone are NNE-trending right-lateral shear zones with extension components,that accord with our study results.Our inversion results are similar with previous studies,which indicate the reliability of our study result.

关 键 词：鄂尔多斯地块 应力场 震源机制解 

分 类 号：P315.12[天文地球—地震学]