库车坳陷克拉苏-依奇克里克构造带的构造演化

野外露头上的小尺度构造记录着整个褶皱逆冲带运动学演化进程。通过对库车褶皱逆冲带坎亚肯褶皱发育的小尺度构造的特征和相互叠加、切割关系的分析,认为克拉苏-依奇克里克构造带在新生代的构造挤压变形中经历了三个阶段,即平行层面的挤压缩短作用阶段、弯滑与弯流褶皱作用阶段和逆冲断层改造作用阶段。同时,对不同阶段出现的断层滑动数据进行反演和古应力恢复的结果表明,整个变形过程,最大主应力方向σ1(即构造缩短方向)集中分布在NNW—SSE,没有发生大的变化,说明三个阶段的构造变形是在同一稳定应力场下发生的,从而进一步证明所有的变形是同一次构造挤压下的渐进式序列变形,而不是多期构造挤压变形的结果。此次构造挤压变形主要发生在康村沉积期(12～5Ma),对于克依构造带的构造圈闭最终定型起着决定性作用。

PROGRESSIVE STRUCTURAL EVOLUTION OF KELASU-YIQIKELIKE STRUCTURAL BELT IN KUQA DEPRESSION

Minor structures in field record a progressive sequence of deformation of an entire fold and thrust belt. Observations of these structures and their overprinting relationships of the Kanyaken fold of Kuqa fold and thrust belt unravel three stages of compressive deformation in the Cenozoic, they are layer parallel shortening, flexural slip and flexural flow folding and modifying by thrusting. Meanwhile, results of inversion on the fault slip data from different stages and paleostress reconstruction show that, the maximal orientation of σ 1, also structural shortening direction, is NNW SSE during the whole compressive deformation. So we can conclude that these deformations of three stages are produced in a same stable stress field progressively, and that they are of progressive sequential deformations, rather than polyphase compressive deformations. This compressive deformation which took place mainly in 12～ 5 Ma did play a crucial role in final formation of these structural trap of the Kelasu Yiqikelike structural belt.