【摘要】 克拉通内古隆起的构造变形是探究板块内部变形行为与大陆流变构造学的理想场所,断裂研究则是其主要突破口。本文基于新的地球物理与钻探资料,对塔里木盆地北部隆起的断裂系统尤其是其北部边界断裂的几何学与运动学开展研究。分析表明,温宿北—野云沟断裂系在重磁场与反射地震剖面上具有清楚的反映,为塔北隆起的北部边界断裂,长达600 km,自西向东由温宿北断裂、温巴什断裂和野云沟断裂三段构成。该断裂系是在早奥陶世末沿基底软弱带自南向北逆冲形成的大型断层相关褶皱带基础上在前翼发生突破而形成的,加里东末期形成雏形,二叠纪末期,受南天山洋关闭的影响由北向南的强烈挤压形成自北而南的逆冲构造系统。该逆冲系统迁就原加里东期的滑脱面发育,并对原来的逆冲系统进行叠加、改造,形成一系列小断块叠加的大型背冲断裂系统,使得该断裂带基本定型。喜马拉雅期塔北隆起轴部发育张扭性断裂构造系统,该断裂系遭受左旋压扭,断裂的活动时序自东向西趋晚,具有长期演化、多期发育、继承、叠加与复合的特征。活动强度呈古生代强烈、中生代—新生代早期弱化、新生代晚期趋强的"强-弱-强"的演化趋势,在横向上呈西段强烈、东段略弱的特征。其成因主要与早奥陶世末期北昆仑洋关闭、二叠纪末期南天山洋关闭、古近纪新特提斯洋关闭引起的周缘地体与塔里木地块的碰撞拼合相关,表现出周缘板块构造事件对板内变形的强烈影响。该断裂系是重要的油气富集带。研究其成因与演化有助于该带油气勘探的拓展,例如西秋断裂带的油气发现。更多还原

【Abstract】 The structural deformation of paleo-uplifts in the cratonic basin is an ideal place to explore the deformation behaviors in the interior of the tectonic plates and the continental ductile structural geology,with the study of faulting being a breakthrough point in this aspect.Based on the newly acquired geophysical data and the recently finished exploratory wells,this paper discusses the fault systems of the north Tarim uplift of the Tarim basin,especially the geometry and kinematics of the northern boundary fault of Tarim basin.It is discovered that the Wensubei-Yeyungou fault acts exactly as the northern boundary fault,having distinct reflections in the gravitational and magnetic fields as well as along the seismic profiles.It is 600 km in length,and is composed of three segments from west to east,i.e.,Wensubei fault,Wenbashi fault,and Yeyungou fault.It was first produced at the end of Early Ordovician,resulting from the breakthougth at the front limb of a large fault-related fold system caused by the subduction of the thrust fault into the basement ductile detachment zone from the south to the north.It took its shape at the end of the Caledonian movement.By the end of Permian period,responding to the strong compression from the north,the southward thrust tectonic system not only took the shape of the former detachment zone,but was also superimposed upon and modified the former Caledonian thrust tectonic system,giving rise to a large-scale anti-form thrust system consisting of a series of small-scale fault blocks,and made the whole fault zone take its shape finally.During the Himalayan movement,the tensile-torsional fault system was developed along the axial zone of the north Tarim uplift.The Wensubei-Yeyungou fault zone was subjected to sinistral transpression,and the re-activation was propagated from the east to the west.Hence it was characterized by prolonged evolution,multi-stage development,inheritance,superposition,and compounding.It had a marked trend of a strong-weak-strong evolution process,namely,the activity was strongest in the early Paleozoic,became weakened or calm in the Mesozoic-early Cenezoic period,and got stronger once again in the late Cenezoic.The faulting in the western segment was possibly much stronger than that in the eastern segment.Its formation was largely related to the collision between the Tarim continental block and the peripheral terrains due to the closing of the North Kunlun Ocean at the end of the early Ordovician,the closing of the South Tienshan Ocean at the end of Permian,and the closing of the Neo-Tethyan Ocean in the Paleogene respectively.These phenomena suggest the important influences of the adjacent plate tectonic events upon the intra-plate deformation.The fault zone seems to be an important oil and gas accumulation zone.The study of the mechanism and evolution is helpful to the expansion of hydrocarbon exploration in the area,as evidenced by the discovery of oil and gas resources in the Xiqiu anticlines.更多还原