库车前陆盆地喜马拉雅运动特征及其油气地质意义

Characteristics and petroleum geological significance of Himalayan orogeny in Kuqa foreland basin

曾联波

Zeng Lianbo

根据构造变形解析和岩石记忆信息,库车前陆盆地的喜马拉雅运动可以划分为3期,它们对应的时间分别为渐新世末、上新世末和早更新世末,其构造挤压强度依次由弱变强,在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,也是该区异常高压形成和油气成藏的主要时期。中更新世以来为新构造运动阶段,主要表现为2～3次重要的抬升和相对较弱的褶皱逆冲变形,并对该区的油气藏主要起破坏作用。库车前陆盆地的构造变形从喜马拉雅早期开始发育,各构造带的发育时间从北往南依次由早变晚,它控制了该区断层相关褶皱、构造圈闭及其油气藏的带状分布规律。喜马拉雅晚期强烈的水平构造挤压是该区异常高压形成的主要因素,是该区油气形成分布的主要控制因素和驱动力,喜马拉雅运动对该区的油气藏有一定的破坏调整作用。

Himalayan orogeny is the main period of tectonic deformation and finalization of structures,as well as occurrence of abnormal high pressure and hydrocarbon accumulation in Kuqa foreland basin.Based on analysis of tectonic deformation and rock memory information,Himalayan movement in Kuqa foreland basin can be divided into three stages,corresponding to the end of Oligocene,the end of Pliocene and the end of early Pleistocene,with compressional intensity progressively strengthening and reaching peaks in late Himalayan.The neotectonics since middle Pleistocene mainly result in two or three uplifts,relatively weak folding and thrusting,and destruction of hydrocarbon accumulations in the area.Structural deformation in Kuqa foreland basin have been developed since early Himalayan,and the structural zones have successively been developed later and later southwards,which control the zonal distribution patterns of thrust folds,structural traps and oil and gas pools.The strong lateral compression in late Himalayan orogeny is the main factor leading to the abnormal high pressure,and the main controlling and driving forces for hydrocarbon migration and accumulation.Himalayan orogeny destroys and adjusts,to some extent, oil and gas reservoirs in the area.

10.11743/ogg20040210