帕米尔弧东段逆冲推覆构造特征  

Characteristics of Overthrust in the Eastern Pamir Structural Arc,Western Tibetan Plateau

作　　者：宋扬[1] 胡建中[2] 王瑞江[3] 李瑞清[1,4] 田斌[1] 李世杰[1] 

机构地区：[1]中国地质大学地球科学与资源学院,北京100083 [2]中国地质大学地学实验中心,北京100083 [3]中国地质科学院矿产资源研究所,北京100037 [4]筑波大学生命与环境学院

出　　处：《现代地质》2011年第1期15-21,共7页Geoscience

基　　金：中国石化西部新区勘探指挥部项目(XBKY04-44-04);中央级公益性科研院所基本科研业务费专项项目(K0803)

摘　　要：帕米尔弧形构造带是青藏高原碰撞挤压表现最明显的地区之一。通过构造剖面和地震剖面解释,认为帕米尔弧东段逆冲推覆构造具有分带性特点,自南西向北东方向可以划分为逆冲推覆构造的根带、中带、锋带与锋前带,相应地发育叠瓦状逆冲断层、冲断褶皱、断层相关褶皱、单斜构造等不同的构造组合。对逆冲推覆锋带中苏盖特和阿克陶生长背斜、生长地层及形成时序分别进行了研究,确定了帕米尔弧形逆冲推覆构造以前展式(背驮式)向前陆方向扩展,逆冲推覆始于上新世,并一直持续到早更新世。弧形构造东西两段逆冲推覆运动方式和地层缩短量有很大差异:西段为与挤压方向垂直的逆冲,而东段为斜冲兼顺时针走滑;西段地层缩短量大于东段。Pamir structural arc is one of the most intensively deformed areas produced by continued compressing of Tibetan Plateau after collision between Indian and Eurasian plates.Geological investigation and interpretation for the seismic section in the eastern Pamir structural arc revealed that thrust nappe was composed of 4 zones from southwest to northeast,i.e.,root zone,middle zone,frontal zone and frontal out zone,which are characterized by imbricate thrusting,thrust fold,fault related fold and monoclinal structure,respectively.The study of growth strata of Sugaite and Aketao growth anticlines occured in the frontal zone indicated that the Pamir structural arc was characterized by piggy-back imbricated duplex.The deformation time was constrained at Pliocene to Early Pleistocene by growth strata and unconformity.The kinematical mode of thrust nappe was different between eastern and western sections.The thrusting in the west is vertical to extrusion direction,and in the east is oblique and clockwise strick-slipe.The stratum shortening in the west was much bigger than that in the east.

关 键 词：帕米尔弧形构造 逆冲推覆 前展式 地层缩短量 

分 类 号：P542[天文地球—构造地质学]