Abstract: Fold-thrust belts and salt-related structures are very prevalent in the Kuqa foreland fold-thrust belt of Tarim Basin in Northwest China.The seismic data interpretation and field observation on the structural features of Qiulitake structural belt in the leading edge of Kuqa foreland fold-thrust belt show that there are two layers of halite acting as detachment levels in the Cenozoic of this area.The structural features in perpendicular and horizontal domains are very different as the result of the variety of the halite-detachment levels.The interpretation of seismic profiles indicates that the structural styles mainly include salt welddings,fault-detachment folds,fault-propagation folds,fault-bend folds,triangle zones and their composites,as well as basement-involved fault-related folds.Influenced by the north-south compressive stress,the evolution of salt-related structures in Qiulitake region experienced four stages of wedged-bed formation,detachment fold,detachment fault and opposite-thrusting faults.

Key words: foreland fold-thrust belt, salt-related structures, fault-related folds, detachment levels, formation mechanism

摘要： 褶皱-冲断带和盐相关构造均十分发育的秋立塔克地区构造极其复杂,该地区新生界内部存在两套起滑脱层作用的膏盐层.受滑脱层位置变化影响,垂向上和平面上的构造变形特征均具有很大差别.地震剖面识别出的构造样式主要有盐焊接、断层滑脱褶皱、断层传播褶皱、断层转折褶皱、三角带及其混生构造样式和基底卷入型断层相关褶皱等.秋立塔克地区盐相关构造形成的主要动力是挤压应力,其形成过程主要经历了楔状地层、滑脱背斜、滑脱断层和对冲断裂形成4个阶段.

关键词: 前陆褶皱-冲断带, 盐相关构造, 断层相关褶皱, 滑脱层, 形成机制