南天山山前冲断带的构造样式及成因探讨

塔里木盆地南天山山前冲断带东西分段、南北分带.受走滑断裂控制,自西向东分为喀什北缘、西克尔区段、柯坪断隆主体、温宿凸起和库车坳陷.受南天山逆掩推覆作用影响,发育多排NE向构造带,喀什北缘主要发育乌恰、阿图什、喀什3排构造带,柯坪断隆主体发育3排古生界逆冲褶皱带,库车坳陷主要由北部单斜带、克拉苏—依奇克里克、秋里塔格构造带组成.由于山前带基底结构和构造运动的差异,造成了各区段地层分布的不均衡,普遍发育的逆冲断裂和走滑断裂,使得地质结构和构造样式更为复杂,多套塑性地层对区带展布和构造变形起到了重要作用.

DISCUSSION ABOUT THE TECTONIC STYLES AND THE CAUSE OF FORMATION OF THE STRUCTURES IN THE PRECORDILLERA THRUST BELT OF SOUTHERN TIANSHAN MOUNTAIN

Precordillera thrust belt(PTB)in Southern Tianshan Mountain(STM)of Tarim Basin is separated into segments in West-East direction and into belts in South-North direction.Controlled by the strike-slip faults,it's separated into 5 segments from west to east,as Kashi North Edge,Xiker Segment,the Main part of Keping Upheaval,Wensu Uplift and Kuche Depression.Affected by the overthrust of STM,several NE-SW tectonic belts are formed in this area.There are mainly three tectonic belts namely Wuqia,Atushi and Kashi in Kashi North Edge and three Paleozoic thrust fold belts in the Main part of Keping Upheaval.Kuche Depression is mainly composed of Northern Monocline Belt,Kelasu-Yiqikelike Belt and Qiulitage Belt.Because of the differences in basement structures and tectonic movements in the precordillera belts,the strata are unevenly distributed in each of the segments.The ubiquitous thrust faults and strike-slip faults complicate the geological structures and the tectonic styles in the studied area,and there are several sets of plastic layers which play an important part in the segments distribution and the tectonic deformation.