香山北缘活动断裂带东段构造特征及活动性分析  

Structural features and activity in the east segment of Xiangshan northern margin active fault zone

作　　者：李海峰 马学东 李明涛 梁志荣 黄生金 

机构地区：[1]宁夏地质调查院,中国银川750021

出　　处：《地震学报》2014年第2期306-317,340,共12页Acta Seismologica Sinica

基　　金：中国地质调查局1:5万地质调查项目(1212010510409)资助

摘　　要：在野外实测工作基础上,对香山北缘活动断裂带东段自晚更新世以来的水平活动强度分时、分段进行了研究.结果表明,该断裂带东段自晚更新世以来,总体水平活动强度不大:晚更新世早—中期水平位移速率为1.44mm/a,晚期水平位移速率为0.53mm/a,全新世水平位移速率为1.01mm/a.该断裂带左旋走滑强度在走向上具有不均一性,而且其活动强度的最大部位(活动中心)随时间向东发生迁移,碱沟—刘岗井次级断层是现今活动强度最大的次级断层.Xiangshan northern margin active fault zone, mainly characterized by sinistral strike-slip faults with a little dip-slip component in the Holocene, is one of the important active faults of arc structural belt in the northeast margin of Tibetan Plateau. The fault zone consists of nine discontinuous secondary faults and is divided into eastern and western segment by the Yiwanquan discon- tinuity. Based on the field survey, the study on active intensity of the eastern segment of the fault zone since the Late Pleistocene has been conducted in dif- ferent periods. The results show that the active intensity of the east segment since the Late Pleistocene is not strong because the average horizontal displace- ment rates are 1.44, O. 53 and 1.01 mm/a in early-middle stage of Late Pleisto- cene, late stage of Late Pleistocene, and Holocene, respectively. The sinistral strike-slips of the faults distribute inhomogeneously along the strike, and thelocation of the maximal slip （the center of the activation） displaced eastward, resulting in the Jiangou-Liugangjing secondary fault being the most active part up to now.

关 键 词：活动断裂带 构造特征 滑动速率 活动强度最大部位 

分 类 号：P315.2[天文地球—地震学]