库车坳陷活动构造的基本特征  

THE BASIC FEATURES OF THE ACTIVE TECTONICS IN THE KUQA DEPRESSION OF THE SOUTHERN TIANSHAN

作　　者：沈军[1] 吴传勇[1] 李军[1] 向志勇[1] 陈建波[1] 谢天[2] 宋正娜[1] 王翠[2] 

机构地区：[1]新疆维吾尔自治区地震局,乌鲁木齐830011 [2]新疆大学资源与环境学院,乌鲁木齐830046

出　　处：《地震地质》2006年第2期269-278,共10页Seismology and Geology

基　　金：新疆科技攻关项目(200333116);中国地震局"新疆巴楚-伽师6.8级地震应急工作专项计划"项目;科技部国际合作重点项目(2004DFBA0005)资助

摘　　要：简要介绍了南天山山前库车坳陷的主要活动逆断裂-背斜带的分布特征、构造样式、最新活动证据等资料。平面上库车坳陷呈一“眼”状,由南北两大背斜带构成。北部靠近南天山为一套向南逆冲的逆断裂-背斜系统,最新活动的逆断裂-背斜带为喀桑托开逆断裂-背斜带;南部靠近塔里木盆地的是一套向北逆冲的逆断裂-背斜系统,最新活动的主要是秋里塔格逆断层-背斜带及其以南的亚肯背斜等新背斜;南北两大背斜系统夹持着拜城盆地。坳陷区北部的喀桑托开断裂与坳陷区南部的秋里塔格断裂带是区内最主要的活动断裂,前者长逾60km,后者长近200km,沿这两条断裂带均发现了清楚的断裂露头和古地震形变带。此外,在秋里塔格背斜带以南发育了更新的、规模较小的背斜,表明库车坳陷区的褶皱作用继续向盆地方向扩展。石油地震剖面资料显示,库车坳陷南北两侧的褶皱作用均受盖层与基底之间的滑脱断层控制,属于山前的薄皮构造。滑脱面的深度可达10km左右。这是库车坳陷主要的发震层。The distribution, tectonic style and new displacement and other features of the main active tectonics in Kuqa depression in the front of southern Tianshan were introduced in this paper. This depression is an ＂eye-shaped＂ tectonics in plane. It is composed of two fold zones in the south and north respectively. The northern one close to the main southern Tianshan Range is a southward thrusting fault-folding system. The most recent active fold in this system is the Kasangtuokai fold belt. The southern one close to the Tarim Basin is a northward thrust fault-fold system. The recent active folds in this system are the Qiulitage fault-fold belt and other young folds in its south, such as the Yaken fold. These two folding systems embrace the Baicheng Basin which likes an eyeball in the eyelids. The Kasangtuokai Fault with a length of 60km in the north and the Qiulitag Fault with the length over 200km in the south are the most important active faults in Kuqa depression. The younger and smaller folds in the south of Qiulitag anticline belt indicate the southward propagation of the thrust fault in Kuqa depression. The petroleum seismic profiles show that the folding and faulting processes are controlled by the detachment fault between the sediment cover and the basement of the basin. The depth of the detachment fault is around 10km and possibly defines the main seismogenic zone in the depression area.

关 键 词：活动构造 库车坳陷 天山 

分 类 号：P315.2[天文地球—地震学]