吐鲁番坳陷走滑断层特征探讨

Characteristics of strike-slip fault in Turpan Depression of Tuha Basin

吐哈盆地经历多期构造运动,构造作用相互叠加,中浅层断裂特征、构造样式复杂多变。盆地西部吐鲁番坳陷由于持续受到南北向构造应力作用,平面上"南北分带、东西分块"、剖面上"盖层滑脱"。由于侏罗系广泛发育煤层,加之挤压地质作用横向差异性强,吐鲁番坳陷中浅层发育大量走滑断层,断层特征纵、横向变化较大,对油气成藏控制作用明显。综合利用卫星照片、地面地质露头及地震资料,对吐哈盆地吐鲁番坳陷的走滑断层进行了较系统的分析和总结,重点探讨了走滑断层的类型、平面分布、剖面特征及其形成机制,结合已知油气藏分布特征探讨了走滑断层对油气成藏的控制作用,指出了下步勘探的有利区带。

Tuha Basin had experienced multiphase tectonic movements which were superimposed with complicated faults and structural style in the middle-shallow formation. The Turpan Depression in the west of the basin shows characteristics of 'N-S zoning and E-W partitioning' areally and 'caprock decollement' vertically as a result of continuous NS-trending tectonic stress. Because of the widely developed coal seam and the lateral diversity of geologic compression in Jurassic strata,a large number of strike-slip faults had developed in the middle-shallow formation of Turpan Depression. These faults change drastically in both vertical and lateral directions and obviously control hydrocarbon accumulation. The strike-slip faults in Turpan Depression of Tuha Basin are systematically analyzed and summarized by using satellite photographs,geological outcrops and seismic data,and discussed in respects of type,distribution,profile feature,and formation mechanism. The control action of strike-slip faults on hydrocarbon accumulation is discussed by combining with reservoir distribution characteristics already known. The favorable zones of future exploration are delineated.