准噶尔盆地西北缘克-夏断裂带构造特征新认识

Structural Characteristics and Its Significance for Hydrocarbon Exploration of Karamay-Xiazijie Fault Zone,Northwest Margin of Junggar Basin

综合研究地表实测剖面、二维-三维地震资料及时频电法剖面,认为准噶尔盆地西北缘克-夏断裂带兼具逆冲推覆特征与压扭走滑特征。实钻资料证明下古生界构成的推覆体逆冲到二叠系上,表明造山带曾发育逆冲推覆构造。但其剖面断裂呈陡-缓-陡的椅状,与达尔布特断裂相交构成花状断裂,表现为右行走滑特征,表明克-夏断裂带为受达尔布特断裂控制发育的压扭性走滑构造。结合区域构造运动背景分析,认为克-夏断裂带于晚石炭—早二叠世发育为冲断及推覆构造,晚二叠世之后受达尔布特断裂控制发育为右行走滑构造。

Comprehensive research of surface profile、2D-3D seismic data and time-frequency profile plot,make known the thrust／strike- slip belt characteristics of Karamay- Xiazijie fault zone.The drilling data show that early Palaeozoic nappe thrust above Permian- Triassic stratum.The fault presents steep- slow- steep on the profile,like chair.At the same time,the fault that intersects with Dalabute fault formed flower structure,shows dextral strike- slip.Fold belt also developed strike- slip structure.Regional tectonic background analyses,Karamay- Xiazijie fault zone developed thrust- nappe during Carboniferous to Early Permian and dextral strike-slip during late Permian.