摘要
宁夏香山—天景山地区逆冲推覆构造由天景山北麓断裂带(主滑脱断裂)和香山-天景山冲断席(可分为9个次级逆冲推覆岩席)组成,推覆岩席前端为一系列形态相似的铲式叠瓦状逆冲推覆断层,构造变形强烈;岩席内部构造变形相对较弱。整个推覆构造带主要遭受了燕山期和喜马拉雅期挤压逆冲推覆作用,燕山期主压应力σ1方向为44°,由南西往北东推覆,总位移量26.6km;喜马拉雅期主压应力σ1方向为75°,由南西西往北东东逆冲推覆,晚更新世以来还兼有左行走滑,总位移量大于4km。
The thrust nappe structure in the Xiangshan-Tianjingshan area, Ningxia, consists of the Tianjingshan northern piedmont fault zone (main detachment fault) and Xiangshan-Tianjingshan thrust sheet (which may further divided into nine second-order thrust sheets). The front of the thrust sheet is composed of a series of nearly parallel listric, imbricate thrust nappe faults and its tectonic deformation is strong, while tectonic deformation inside the thrust sheet weak. The thrust nappe as a whole underwent Yanshanian and Himalayan compression and nappe-thrusting. In the Yanshanian period the principal compressional stress σ1 was oriented in a 44° direction and the nappes was thrust northeastward with a total displacement of 26.6 km. In the Himalayan period, the principal compressional stress σ1 was oriented in a 75° direction and the nappes was thrust from SWW to NEE. Since the late Pleistocene, there also occurred left-lateral strike-slip motion with a total displacement of more than 4 km.
出处
《地质通报》
CAS
CSCD
北大核心
2005年第4期309-315,共7页
Geological Bulletin of China
基金
中国地质调查局1:25万吴忠市幅区域地质调查项目(编号:20001300004031)成果之一。
