辽西地区燕山板内造山带东段中生代逆冲推覆构造  

Thrust Tectonics in the Eastern Segment of the Intraplate Yanshan Orogenic Belt,Western Liaoning Province,North China

作　　者：张长厚[1] 王根厚[1] 王果胜[1] 吴正文[1] 张路锁[1] 孙卫华[1] 

机构地区：[1]中国地质大学地球科学与资源学院,北京100083

出　　处：《地质学报》2002年第1期64-76,共13页Acta Geologica Sinica

基　　金：国家自然科学基金委员会青年基金(编号49702034;49802019);国际合作项目(编号49910121214;40111120436);中国地质调查局1:25万区域地质调查项目(编号20001300005141)资助的成果。

摘　　要：本文厘定并阐述了辽西地区燕山中生代板内造山带东段发育的逆冲推覆构造的宏观构造格局、运动学特征、形成时代和形成过程;探讨了形成该构造体系的区域构造背景及其大地构造意义。该区的逆冲构造系统由6条主干逆冲断层组成。分布于西北和东南缘的两条最外缘道冲断层走向为ENE,居于其间的逆冲断层呈NNE—NE,而且,向东北和南西方向这些断层具有汇合的趋势。在东北端收敛于凌源—东官营子断裂(“内蒙地轴”南缘断裂)上,而在西南端则汇拢于大屯—锦州断裂及其西延的密云—喜峰口断裂。总体上构成一个类似于双重构造(duplex)的巨型逆冲系统。该区边冲作用始于中侏罗世之前,于侏罗纪末达到高峰并基本形成了本区的推覆构造格局。本区逆冲断层系统,总体逆冲方向指向南东,与燕山板内造山带中段、西段以向北、北西逆冲为主的逆冲推覆构造明显不同。结合燕山中段发现的近东西向右行走滑断裂系统及其与本区逆冲推覆构造体系的时-空关系分析,指出本区逆冲推覆构造的形成,是沿燕山东西向构造带右行走滑作用因构造方向的改变发生构造转换的结果。The tectonic framework, kinematics and the development of the thrust fault system of the eastern segment of the Mesozoic intraplate Yanshan orogenic belt in western Liaoning province are described in the paper. The tectonic settings and the significance of this fault system have been evaluated following the aforementioned de-scription. The thrust fault system consists of six master thrust faults. Both the northwestern and the southeast-ern faults of them extend east-north-east. The thrust faults between them take, however, the orientation of north-east-north. All these thrust faults tend to be connected together in the northeast and the southwest part respectively. In the northeastern part they tend to get together along the Lingyuan-Dongguanyingzi thrust fault. In the southwestern area they seem to be getting together along Yaolugou-Jinxi fault zone and its coun-terpart , Miyun-Xifengkou fault zone to the west. Structurally all those thrust faults form a tectonic frame-work which looks like a large-scale duplex. Both the geological interrelations and the dating results define a de-velopment sequence of the thrust fault system in this area. The thrusting commenced before Middle Jurassic and reached its deformation peak at the end of Jurassic. The tectonic framework of thrust faults in the area formed as a result of the extensive contraction during this time interval. Top-to-the-southeast movement dominates the thrusting of this tectonic system, which differ profoundly from those thrust faults in the middle and western parts of the intraplate Yanshan orogenic belt in propagation vergence. The spatial and temporal relations be-tween these thrust faults and the east-west trending dextral fault systems in the middle part suggests a unified tectonic model. This model implies that the top-to-northwest thrusting in middle and western part and the top-to-southeast thrusting in the eastern segment of Yanshan intraplate orogenic belt might formed as a result of a right lateral transform deformation along the latitude fault

关 键 词：逆冲断层系统 双重构造 板内造山带 燕山 辽宁 中生代 辽西地区 

分 类 号：P534[天文地球—古生物学与地层学]