西昆仑山前甫沙—克里阳地区新生代变形特征及油气控制作用

Cenozoic structural deformation of the Fusha-Keliyang area in the piedmont of the western Kunlun Mountains and its control on hydrocarbon accumulation

甫沙—克里阳地区位于西昆仑山弧形构造带的东段,是研究西昆仑山前冲断带变形特征的关键区域。在详细地面地质调查和钻井分析的基础上,利用最近完成的高分辨率地震资料,对甫沙—克里阳地区的新生代构造变形特征进行了研究。认为研究区自南向北由甫沙、柯克亚和固满—合什塔格3排构造带组成,其中甫沙构造带的结构特征在横向上有较大差异;3排构造带变形时间由南向北变新,冲断带表现为"前展式"的变形,同一排构造带的变形存在着由西向东迁移的特征;研究区新生代总缩短量为54.5km,缩短率为35.9%;新生代构造变形对研究区的油气聚集具有重要的控制作用,甫沙构造带的深层构造是下一步最有利的勘探领域。

The Fushan-Keliyang area is situated in the eastern segment of the western Kunlun arc tectonic belt,providing key constraints for studying deformation characters of the western Kunlun piedmont thrust belt.Combined with geologic survey,drilling data and recent high-resolution seismic profiles,this study analyzed the Cenozoic deformation characters of the Fushan-Keliayang area.The present paper proposed that the studied area consisted of three ranges of structural belts from south to north,i.e.Fusha,Kekeya and Guman-Heshitag,of which the Fusha structural belt showed obviously lateral variations in configuration characters.Among these structural belts,the deformed timing of individual structural belts got younger northward,displaying characters of ＂break-forward＂ deformation.Within the each range of structural belts,deformation propagated from west to east.Based on the balanced section calculation,the total shortening of the Cenozoic structural belts in the Fusha-Keliyang area accounted for 54.5 km and the shortening rate was 35.9%.Therefore,the Cenozoic deformation greatly controlled hydrocarbon accumulation,and deep structures of the Fusha structural belts were considered to be the best target for hydrocarbon exploration.