塔里木盆地巴楚隆起断裂差异活动特征及成因演化

The differential activity characteristics and its evolution of the faults in the Bachu Uplift,Tarim Basin

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,严重制约了对该地区构造特征及演化的认识和油气勘探工作。本文通过对地震资料精细构造解释,并结合塔里木盆地构造演化背景及最新的钻井、露头等资料,阐明了巴楚隆起断裂活动具有明显的分期差异性和分区、分带、分段及分层差异性。巴楚隆起断裂构造主要经历了4期差异活动,即加里东早期发育张扭性断裂、海西晚期断裂挤压反转、喜马拉雅山中期断裂强烈压扭逆冲与分区差异变形、喜马拉雅山晚期西南缘断裂带分段分层差异改造与叠加。断裂演化主要受控于加里东早期、海西晚期和喜马拉雅山中-晚期构造运动及对应时期塔里木古陆周缘洋盆开合与造山作用,喜马拉雅山中期是巴楚隆起断裂活动关键期,因受西昆仑和西南天山强烈挤压,隆起西段发生"屈服型"冲断隆升与走滑旋转,东段相应发生"受限型"弧形逆冲与向南掀斜;喜马拉雅山晚期断裂主要活动表现在隆起西北缘和西南缘,特别在西南缘断裂带发生了强烈的分段、分层差异叠加改造,其成因与西昆仑强烈隆升和向北挤压密切相关。

The Bachu Uplift is one of the most important oil and gas exploration area in the Tarim Basin, but the realization of its structure characteristics and evolution as well as the oil and gas exploration are serious constrained by its exceptionally complex faults structure and evolution. Based on the fine structural interpretation of seismic data,the tectonic setting of Traim Basin＇s evolution ,the new wells data and outcrops ,the paper reveals that the activity characteristics of the faults in Bachu Uplift has great difference in different period, different area, and different fault belt, different parts of the same fault, different stratigraphic. There are mainly four periods of the faults＇ differential activities： Transtensional faults activities in Early Caledonian, positive inversion of early transtensional faults in Late Hercynian, strong strike-slip and thrust and different deform in Middle Himalayan, different transformation and superposition in different parts and stratigraphic in the southwest faults belt in Late Himalayan. Fault evolution is mainly controlled by the tectonic movements of the Early Caledonian, the Late Hercynian and the Middle-Late Himalayan, as well as the opening and closing of oceans surrounding the Tarim paleo-continent and the orogenic movements in the corresponding period. The Middle Himalayan is the critical period for faults activities in the Bachu Uplift, because of the strong compressive stress come from the West Kunlun Mountains and the Southwest Tianshan Mountains,faults in the western part thrust uplift and strike-slip rotation, faults in the eastern part thrust like an arc and tilting to the southward. The Late Himalayan is the deformation period of the faults and it mainly occurs in the northwest edge and the southwest edge of Bachu Uplift, especially in the southwest edge, because of the strong compressive stress comes from the West Kunlun Mountains, strong different deformation and superposition occur in different parts of the southwest faults belt.