准噶尔盆地西北缘横断层特征及形成机制探讨

准噶尔盆地西北缘是全盆地油气最为富集的区域， 沿着北东向克-乌断裂带有数条北西向横断层分布， 与主断裂直交或斜交， 这些横断层具有重要的构造与成藏意义。 运用地貌影像资料、区域布格重力异常、地震资料， 标定出横断层， 并分析其特征， 最后结合构造模拟实验探讨了横断层形成机制。 研究表明：1） 准噶尔盆地西北缘横断层是克-乌断裂活动产生的伴生构造， 呈近等间距分布在克-乌断裂带上， 为北西走向， 具有走滑性质；2） 构造模拟实验结果表明， 这些横断层主要为斜向挤压环境下形成的 X 型共轭剪切断层或主逆冲断裂活动差异造成的调节断层。

Characteristics and the forming mechanisms of transverse faults in northwestern margin of Junggar Basin

Northwestern margin of Junggar Basin is the richest region of oil and gas in the whole basin. There are several NW tending transverse faults being perpendicular or oblique to the NE-directed Ke-Wu fault. These transverse faults have serious significance for tectonic and hydrocarbon accumulation. By analysing and interpreting the data of topographic image, regional Bouguer gravity anomalies and seismic data, the transverse faults are identified and their characteristics are also analysed. Finally according to the results of the structure modeling experiments, the formation of the transverse faults are investigated. Researches show that firstly, there indeed exists a series of NW-toward transverse faults of different size, distributed in between approximately equal distance; secondly, the structure modeling experiments shows that these transverse faults may be from the X-type conjugate shear faults formed under the tectonic condition of oblique compression or the accommodating faults caused by the difference activities of the main thrust fault. These transverse faults are the associate structure of the Ke- Wu thrust nappe belt, with the properties of strike slip.