库车前陆冲断带横断层发育特征及其形成机制

Development characteristics and formation mechanism of transverse faults along the Kuqa thrust belt

横断层是指走向与主构造走向线直交或大角度相交的伴生断层,在冲断带中普遍存在且具有一定的研究意义。库车前陆逆冲带是中亚地区典型的逆冲褶皱带,是经历多期构造形成的再生前陆盆地,具备发育横断层的构造基础。结合前人资料,通过对地貌遥感影像、深部物理资料以及地震勘探等资料的分析解译,对库车前陆冲断带的横断层构造特征、形成机制以及地质意义进行了探讨。通过研究发现:(1)库车前陆冲断带存在16条主要横断层(组),其中9条横断层结构及性质确定,总体来看主要分布在北部单斜带、克拉苏构造带以及秋里塔格构造带;(2)依照形成机制,研究区横断层可以分为基底断裂活化型走滑横断层、盖层撕裂型走滑横断层以及盐上张性横断层三大类;(3)横断层在调节冲断带不同段逆冲差异、横向河流发育、丰富构造样式以及控制油气运移等方面具有一定的地质意义。

Transverse faults are widespread in the thrust belt,and the study of these faults is significant and valuable. Having experienced multi-episodic tectonic changes, the Kuqa thrust belt has had the structural foundation of developing transverse faults.In combination with the remote sensing image, deep geophysical data and seismic section analysis,the authors studied the tectonic characteristics and genetic types of transverse faults in the Kuqa thrust belt. Some conclusions have been reached：（1） There are 16 transverse faults in the Kuqa thrust belt, with structure and properties of nine faults being confirmed. These transverse faults aremainly distributed in northern monocline tectonic zone, Kelasu tectonic zone and Qiulitag tectonic zone;（2） Transverse faults can be divided into three genetic types, i.e., basement activation transverse fault, cover-tear fault and tensional transverse fault;（3）Transverse faults have some geological significance in adjusting the thrust displacement difference between segments, developing transverse rivers, enriching structural styles and controlling oil and gas migration.