通过对塔中低凸起北斜坡4500km^2三维地震数据体的精细解析,根据不整合面和生长地层分析以及断层与地层之间的接触关系,厘定划分出4期不同应力性质的断裂,分别为寒武纪—早奥陶世拉张断裂、晚奥陶世冲断挤压和北西向走滑断裂、志留纪—泥盆纪北东向走滑断裂以及二叠纪的岩浆刺穿。寒武纪—早奥陶世拉张断裂展布形态和发育规模奠定了后期构造活动的基础;晚奥陶世断裂呈发散的帚状,向东南方向收敛,断裂分布具有明显的分带和分段性,东部主要为逆冲断裂,中西部发育北西向走滑断裂,晚奥陶世断裂体系可划分为6组呈北西向展布的弧型断裂带,各弧形断裂带由多条断裂组成,其形成可能与古生代阿尔金北缘北西向冲断挤压有关;塔中志留纪—泥盆纪走滑断裂体系主要是在挤压应力环境下形成的,呈北东向展布,走滑断裂体系由3部分组成:主干边界断裂、尾端羽列断裂和拉分地堑,其中主干断裂剖面上表现为高角度近似直立断面,直插基底,延伸较远,剖面上呈花状构造,尾端羽列断裂在主干断层的尾端发育,主要位于主干断裂的北端,拉分地堑平面上呈菱形,受多级断层控制;二叠纪岩浆刺穿在塔中三维区呈点状或条带状,岩浆刺穿对早期断裂进行叠置和改造,岩浆侵入和底辟作用致使地层隆升,形成一系列逆断层性质的"正花状构造"。构造活动决定了断裂发育,早古生代塔里木盆地及其周缘地区伸展-聚敛构造演化构成了一个较为完整的威尔逊旋回,寒武纪—早奥陶世塔里木周缘古大洋拉张裂解,早奥陶世末—晚奥陶世部分古大洋俯冲消减,晚奥陶世—泥盆纪周缘大洋部分闭合,发生弧陆或陆陆碰撞,二叠纪岩浆活动代表了另一个构造旋回的开始。
Based upon 3D seismic fine interpretation of the 4500 km^2 north slope of Tazhong low uplift, it is divided into four series of fault systems according to the unconformities, growth strata and the contacts of the faults and strata, they are Cambrian-early Ordovician tensional fault systems, late Ordovician thrust compressional fault systems and northwestard slip fault systems, Silurian-Devonian northeastard slip fault systems, and Permian magmatic pierces respectively, among which the Cambrian-early Ordovician tensional fault systems lay foundation for the late tectonic movement. The late Ordovician fault systems converge southeastard and diverge northwestard, and there are obvious zoning and partitioning distribution. It is thrust fault system in the east of Tazhong low uplift and is northwest slip fault system in middle-west. And it can be divided into six series of arched fault belts, every arched fault belt is consisted of several faults. The formation of the late Ordovician fault systems may be the result of the northwestard thrust of the Paleozoic altyn terrain. The Silurian-Devonian slip fault systems are mainly formed in extrusion stress background and spread in northeast direction. The slip fault systems are made up of three parts: the main faults, the tailed en-echelon structures and the fault troughs. The main faults are high- angle approximately upright in seismic section and the the fault troughs are rhombic in plane. The Permian magmatic pierces are distributed in spotty or bandy, and they are mostly developed in the early faults and always superimpose or reform the early faults. The formation of fault system is controlled by tectonic movement, from Cambrian-early Ordovician ancient oceanic tensional cleavage to Silurian-Devonian oceanic closure and the arc-continent or continent-continent collision, the tectonic evolution has formed a relatively integrated Wilson-Cycle, and the Permian magmatic pierces indicate the beginning of another cycle.