准噶尔盆地南缘东部构造样式与形成机制

应用前陆盆地相关褶皱理论,对准噶尔盆地南缘喀拉扎—古牧地复杂构造进行了构造建模与构造形成机制分析,认为喀拉扎—古牧地地区受北天山、博格达、艾卡三组不对称走滑断裂系统的影响,形成了以剪切压扭作用为主的构造。喀拉扎背斜属浅层反向冲断双重构造,古牧地背斜为基底卷入型双重构造;山前推举带西部的齐古一昌吉背斜带与东部的古牧地—阜康背斜带是通过喀拉扎反冲断裂调整与转换而形成的;博格达走滑断裂不对称性,形成了不对称的昌吉向斜,成为一典型的复合含油气系统;喀拉扎与古牧地背斜代表两种不同类型的构造样式,为近期勘探的重要目标。

Structures in East Part of Southern Margin in Junggar Basin and Their Formation Mechanism

The structural model and structural formation mechanism of Karaza-Gumudi complex structures in southern margin of Junggar basin are analyzed by applying folded theory related to foreland basin.Karaza-Gumudi area is subjected to the effects of asymmetric north Tianshan Mountain,Bogda and Aika shove fault systems,being dominated by shear and compresso-shear actions.Karaza anticline belongs to dual structure with shallow reversed thrust;Gumudi anticline to dual structure with basement-involved style.Qigu-Changji anticline belt in west of piedmont thrust zone and Gumudi-Fukang anticline belt in east of it were resulted from adjustment and transform of Karaza reversed fault.Asym-metric Changji syncline was formed by asymmetric action in Bogda shove fault,forming the largest and deepest subsid-ing center followed by a typical complex petroleum system.Karaza anticline and Gumudi anticline as two types of struc-tural styles are major targets for hydrocarbon prospecting in the near future.