喜马拉雅运动在塔里木盆地库车坳陷的表现——来自岩石声发射实验的证据

Expression of the Himalayan orogeny in the Kuqa depression, Tarim basin——evidence from the rock acoustic emission experiment

根据岩石声发射记忆信息,并结合构造变形分析,对塔里木盆地库车坳陷喜马拉雅运动的构造期次和强度进行了研究。喜马拉雅运动在库车坳陷分为3期,其构造挤压强度依次增强,平均最大有效应力值分别为55.7MPa、63.6MPa和79.4MPa,喜马拉雅晚期达到高峰,是该区构造的主要变形期和定格期。库车坳陷构造从喜马拉雅早期开始发育,各构造带的发育时间从北至南依次变晚。在喜马拉雅运动强烈的构造挤压作用下,库车坳陷广泛发育逆冲构造,包括断层相关褶皱、对冲构造、背冲构造、构造三角带、叠瓦构造、被动顶板双重构造等。喜马拉雅运动对库车坳陷油气的生成、储集性能、圈闭、运聚与保存条件有重要的影响,是该区油气形成和分布的主要控制因素。

According to rocky memory information determined by means of acoustic emission, combined with an analysis of tectonic deformation, the tectonic stages and intensity of the Himalayan orogeny in the Kuqa depression, Tarim basin, are studied. The Himalayan orogeny may be divided into three stages. The tectonic compressional intensity of the Himalayan orogeny was increased in the order of the stages. The average maximum effective stress values were 55.7, 63.6 and 79.4 MPa respectively and reached the acme in the late Himalayan orogeny, which was the main stage of tectonic deformation and finalization in the area. Structures in the Kuqa depression began to develop in the early stage of the Himalayan orogeny. The time for formation of various tectonic belts was successively late from north to south. Under the strong tectonic compression during the Himalayan orogeny, various kinds of thrust structure were extensively developed in the Kuqa depression. They include thrust-related fold structure, ramp structure, back thrust structure, tectonic triangle zone, imbricate structure, passive roof duplex etc. The Himalayan orogeny had important influences on oil and gas formation, accumulation capacity, trapping, migration and conservation in the Kuqa depression. It was the main constraint for the formation and distribution of oil and gas in the area.