准噶尔盆地西北缘中拐凸起断裂发育特征及构造变形过程

Fault Characteristics and Deformation Process of Zhongguai Uplift in Northwestern Margin of Junggar Basin

中拐凸起地区经历了多期构造运动,构造叠加效应强烈,断裂系统复杂,亟待厘定。针对上述问题,采用断裂系统分析技术,建立了中拐凸起早期发育压扭断层、晚期发育正断层的"两期叠加断裂发育模式"。平衡剖面分析认为,受区域性构造转换影响,该地区主要经历了5个构造演化阶段:基底隆升阶段、挤压变形阶段、构造转换阶段、伸展改造阶段和构造定型阶段。中拐凸起形成于挤压应力环境,内部发育压扭断层;在晚期伸展条件下,凸起内部发育大量正断层。浅部正断层与深部压扭断层构成纵向叠加,沟通源储,影响成藏。

Zhongguai Uplift has experienced a serious of tectonic activities,developing a complex fault system.Based on these,fault system analysis is used to summarize the fault characteristics:compression-torsion faults developed in early stage while normal faults developed in late stage,forming“two-stage superimposed fault development model”.Balanced cross section suggests that,Zhongguai Uplift has mainly experienced five tectonic evolution stages:basement uplift stage,compression deformation stage,tectonic transformation stage,extensional deformation stage and structural setting stage.Zhongguai Uplift developed in the compression environment,a longing with a serious of compression-torsion faults;when the tectonic environment changed to extension,a serious of normal faults developed,constituting a vertical superposition with early compression-torsion faults,combining the source rocks with the reservoirs,controlling the hydrocarbon accumulation.