塔里木盆地巴楚隆起吐木休克断裂带构造特征及形成演化

巴楚隆起是塔里木盆地重要的含油气构造单元，因其断裂构造特征与演化异常复杂，严重制约了对该区构造特征及演化的认识和油气勘探工作。基于地震剖面的精细地质解释，并结合塔里木盆地巴楚隆起构造演化背景及最新的钻井资料，利用断层相关褶皱理论，识别出吐木休克断裂带3段不同的冲断—褶皱构造样式。西段由一条单一的倾向巴楚隆起的基底卷入型高角度逆冲断层构成。中段除发育南西倾向的主冲断层外，还发育由巴楚隆起向阿瓦提凹陷方向的盖层滑脱构造。同时，断裂上盘褶皱核部发育第四纪正断层。东段为典型基底卷入型楔状冲断构造，冲断构造前锋位于中寒武统膏盐层，上寒武统以上发育低角度的盲冲断层为特征，主冲断层位移量为倾向阿瓦提凹陷的反冲断层吸收。根据地震剖面解释结果及构造演化恢复，认为由基底卷入型主冲断层和盖层滑脱型反冲断层及其相关褶皱构成的深部挤压冲断构造体系，定型于新近纪末。中段挤压隆起顶部中和面附近发育的小型张拱性正断层，形成于第四纪早中期。

Structural characteristics and evolution of the Tumsheg fault belt,Bachu Uplift,Tarim Basin

The Bachu Uplift is one of the most significant oil-gas bearing structural units in the Tarim Basin.It is seriously restricted on the understanding of the structural features and evolution of the regions and the exploration works of oil and gas,because of its abnormally complex structural evolutionary characteristics.Three different kinds of thrust-fold deformation styles were recognized by using the theory of fault-related folds and geometrical characteristics,based on the seismic profiles interpretation combined with the tectonic evolution background and the latest drilling data in the Tarim Basin.In the west section,it was composed of a single high-angle basement-involved thrust fault which inclined towards the Bachu uplift.While in the middle section,besides the main Bachu-inclining fault mentioned above,cover-slipping tectonics were developed from Bachu Uplift to Awati Sag.Meanwhile,a series of Quaternary normal faults were developed on the upper plate of the recoil fault.However,in the east section,it was a typical wedge-shaped thrust structure with basement-involved.The Bachu-inclining main fault had its top stopped at Middle Cambrian gypsum-salt beds.The front of thrust structure was in the Middle Cambrian,while the unbroken strata above Middle Cambrian had their thrust displacement completely absorbed by the Awati-inclining recoil fault.According to the seismic interpretation,it shows that deep extrusion and thrust structural system,which was composed of basement-involved thrust faults,cover-slipping recoil faults and associated folds was formed in Early Neogene and finally stabilized in Late Neogene.Small arch normal faults developed at the top of the extruded uplift in the middle section of the Tumsheg fault belt were formed in the Early-Middle Quaternary.