湘鄂西地区构造演化特征及成因机理分析

Tectonic evolution characteristics and mechanism in Western Hunan-Hubei

本文基于湘鄂西地区二维地震资料,结合研究区野外地质调查资料,认为研究区是江南—雪峰造山带及其前陆冲断带和东秦岭—大别造山带及其前陆冲断带两个盆山体系联合而成的复合盆山体系,具有"两山夹一盆"的区域地质结构。自基底形成以来经历了多期构造运动,构造演化及构造特征复杂,发育多种类型的构造样式,整体具有对冲干涉、南北分带、纵向叠置的结构特征,部分地区存在"双层结构",本文对其演化和成因机理进行了简要的分析。

This study is conducted based on 2-D seismic data and field geological survey data in Western Hunan-Hubei.The following observations are obtained:A.The area is a complex mountain-basin system formed by the Jiangnan-Xuefeng Orogenic belt and its foreland thrust belts,and the East Qingling-Dabie Orogenic belt and its foreland thrust belts,which comprises a regional geologic structure with a basin intervening between two mountains;B.The multi-phase tectonic movements since the basement formed resulted in a complicated tectonic evolution history and characteristics with a variety of tectonic styles.As a whole, structures are characterized by ramp fringe,northsouth zonation,and vertical superimposition.Locally,two-layer structures occur.In addition,the mechanism for evolution and formation is summarized in the paper.