新疆库车地区秋里塔格构造带成因分析

MECHANICAL ANALYSIS ON THE QIULITAGE STRUCTURAL BELT IN KUQA AREA, XINJIANG

秋里塔格构造带位于库车前陆逆冲带前锋 ,区域构造位置介于库车坳陷三叠 侏罗系烃源岩生排烃中心与塔北前缘隆起带之间 ,第三系广泛分布两套膏盐岩层 ,发育多套储盖组合和复杂的构造样式 ,石油地质条件非常优越。本文在分析 3个区带的变形特征基础上 ,探讨了盐上层和盐下层的构造成因 ,认为盐上层的构造成因与盐层的流动性有关 ,西段变形比东段强烈 ;盐下层构造成因东、西差异较大 ,东段与盐层的塑性变形无关 ,西段则受其影响。

The Qiulitage structural belt situated in the front of the Kuqa fold-and-thrust belt,with a regional structural position being sandwiched in between the generating-drainage center of the Triassic-Jurassic source rocks in the Kuqa Depression and the front belt of the North Tarim Rise. There existed widely two layers of evaporite rocks in the Tertiary, with several sets of reservoir-sealing system and complicated structural styles in this area, so as to have an excellent geological conditions for petroleum geology. Based on the deformation characters of three structural sub-belts, namely, the east Qiulitage, west Qiulitage and Quele sub-belts,this paper analyzed the structural causes of the evaporate-above layer and the evaporate-below layer. It could be concluded that the formation of the evaporate-above layer resulted, structurally, from the flow of the evaporite rocks, evidenced by that the western part of the Qiulitage structural belt deformed stronger, since the evaporitic flow better developed there, than that in the eastern part. However, the structural causes of the formation of the evaporate-below layer changed obviouslyly in varied localities.