南天山库车褶皱-冲断带喀拉玉尔滚构造带新生代变形特征及其控制因素

喀拉玉尔滚构造带是南天山库车褶皱-冲断带的变形前缘, 其地下深层变形特征仍然不清楚.结合野外地质调查结果、数字高程模型数据、钻井数据和高品质二维地震反射剖面, 厘定喀拉玉尔滚构造带背斜的平面展布、几何学和运动学特征及变形时间, 并结合前人研究成果探讨喀拉玉尔滚构造带新生代变形控制因素.喀拉玉尔滚构造带为典型的挤压构造带, 近EW向延伸约165km, 由一系列带状背斜组成, 且背斜核部发育多条隐伏逆冲断层.喀拉玉尔滚构造带新生代变形特征主要表现为5个方面: (1)北喀背斜为盐枕构造; (2)中喀背斜和南喀背斜的几何形态不对称、背斜倾伏方向相反, 分别为向北和向南, 二者交汇处发生了位移转换; (3)羊塔克背斜和英买力背斜为基本对称的低幅度滑脱褶皱; (4)背斜幅度整体上从西往东逐渐降低; (5)背斜变形时间从西往东逐渐变新.研究结果表明, 喀拉玉尔滚构造带新生代变形主要受区域挤压作用、盐层和基底构造共同控制. 

Cenozoic Deformation Characteristics and Controlling Factors of Kalayuergun Structural Belt, Kuqa Fold and Thrust Belt, Southern Tianshan

Kalayuergun structural belt (KSB) is the deformation leading edge of Kuqa fold and thrust belt, southern Tianshan, whose subsurface deformation characteristics is still unclear. Based on field observations, digital elevation model, well data and high-quality 2D seismic reflection profiles, we explore the distribution, geometry, kinematics and deformation age of anticlines in the KSB. Combined with the results of previous studies, the deformation controlling factors of the KSB are discussed. KSB extending E-W for about 165km, is a typical compressional structural belt, which is characterized by five elongate anticlines, including Beika, Zhongka, Nanka, Yangtage and Yingmaili anticlines, as well as several blind thrust faults developed at the core of anticlines. Cenozoic deformation characteristics of the KSB are summarized as the following five aspects: (1) Beika anticline is a salt pillow structure; (2) Asymmetric Zhongka and Nanka anticlines have opposite structural vergence, while a displacement transfer zone was formed between them; (3) Yangtage and Yingmaili anticlines are symmetric, low-amplitude detachment folds; (4) The amplitude of anticlines decrease gradually from west to east; (5) The deformation ages were youngling eastward progressively. The results of this study reveal that the major controlling factors of Cenozoic deformation in the KSB are regional compression, salt layer and basement structures.