库车坳陷克拉苏构造带分层收缩构造变形及其主控因素

库车坳陷中段克拉苏构造带广泛发育盐相关收缩构造变形,总体具有"垂向叠置、分层变形"的整体挤压变形特征。沿东-西向克拉苏构造带不同区段深浅层构造变形样式、断层位移存在明显差异,北部盐下层由1～2条高角度基底卷入逆冲断层为主导,并在断层下盘发育捷径断层。区域结构平衡剖面和先存构造活动趋势分析结果表明,克拉苏构造带北侧变形属于基底卷入变形,早期先存断裂在后期收缩变形中重新活动,形成高角度的逆冲断裂。物理和数值砂箱模拟结果表明,盐岩层先于其上、下地层发生变形,其厚度、分布及边界条件差异是造成垂向分层收缩变形的主要控制因素。

Delamination contractional deformation and it main controlled factors of Kelasu structural zone in Kuqa depression

Salt-related contractional structures widely developed in the Kelasu structural zone of mid Kuqa depression,Tarim Basin.The salt bed layer,supra-salt and subsalt bed layer deformed according to their respective abilities and manifested the structural deformation feature of "Whole compression,Delamination deformation".Different structural styles and thrust displacement has displayed along the strike of the Kelasu structural zone.The northern subsalt bed deformation is controlled by high-angle base-involved thrust on which's footwall shortcut thrusts developed.The analysis of the balanced structural interpretation and reactivation tendency reveals that preexisting extensional faults reactived and formed high angle thrust in Northern Kelasu structural zone during contractional deformation.Physical sandbox and numerical sandbox experiment method are used to investigate the main controling factors of salt-related contractional structures in Kelasu structural zone.The simulation show that salt layer is superior deformed,and the distribution of salt bed layer and boundary conditions controlled the vertical delamination contractional deformation.