准噶尔盆地南缘阿什里地区构造特征及有利勘探方向

Structural Characteristic and Prospecting Target in Ashili Area in Southern Margin of Junggar Basin

阿什里地区位于北天山山前冲断带,构造变形复杂,地震剖面反射不清,多年来难以明确其构造变形特征。根据野外地质露头和地震剖面解释,运用平衡剖面技术建立并验证了阿什里地区的构造解释模型,并根据断层发育特征及变形样式的差异,将阿什里地区分为逆掩推覆带、山前变形带和前缘变形带。结合区域地质背景,根据构造变形特征分析,将阿什里地区构造演化分为:晚二叠世的前陆盆地压陷阶段、三叠纪的挤压挠曲阶段、早-中侏罗世的伸展拗陷阶段、晚侏罗世—古近纪的陆内挤压拗陷阶段和上新世以来的强烈挤压阶段。结合区域烃源岩发育特征,根据生烃演化史分析,确定了头屯河构造带为有利勘探方向。

Ashili area lies in the piedmont thrust belt in north Tianshan mountain, with complex structural deformation, poor seismic pro- file and unclear structural characteristics. Based on the field geologic outcrops and seismic interpretation data, the structural interpretation model for this area is developed and verified, combined with regional geologic background and balanced section technique. In view of the fracture development feature and deformation differences, Ashili area can be divided into overthrust nappe zone, piedmont deformation zone, and frontal deformation zone. And its tectonic evolution can be divided into five stages such as the foreland basinal compressive de- pression stage of Late Permian, the compressive-flexural stage of Triassic, the extensional depression stage of Early-Middle Jurassic, intrac- ontinental compressive depression stage of Late Jurassic-Paleocene and 1he intensive compression stage of Pliocene. And according to the regional source rocks development feature and the hydrocarbon-generating evolution history analysis in this area, Toutunhe structural belt is determined as the favorable prospecting target.