温宿凸起构造几何学与运动学特征

Geometry and Kinematics of Wensu Swell in North Tarim Uplift

温宿凸起位于塔里木盆地西北缘塔北隆起西段,作为克拉通内古隆起的一部分,是研究板块内部变形的理想对象。为研究温宿凸起构造几何学与运动学特征,基于钻井、测井、地震、数字高程模型和地质图,结合周缘地区的地层结构,精细刻画沙井子边界断裂和温宿北断裂的几何学特征,以断层相关褶皱理论为指导,建立温宿凸起几何学与运动学模型。研究认为,温宿凸起是由沙井子断裂、温宿北断裂以及基底隆升控制的继承性构造。沙井子断裂早期以断层传播褶皱模式发育,后期沿褶皱前翼发生突破,第四纪末期发育张扭性断裂。温宿凸起的形成起始于早奥陶世末期;二叠纪末期受南天山洋关闭影响,构造基本定型;中生代处于构造松弛期;新生代因南天山造山作用而被强烈改造,温宿凸起及周缘地区总缩短量约35.40 km.断裂的精细研究,尤其是断裂的分期研究,可作为复杂构造解析的突破口。

Wensu swell is located in the northwestern margin of Tarim basin, which belongs to western segment of North Tarim uplift. As apart of paleo-uplift in the cratonic basin, Wensu swell is an ideal object for studying the deformation behaviors in the interior of tectonicplates. Based on drilling data, logging information, 2D seismic data, Digital Elevation Model（DEM）and geological map and combining withthe stratigraphic texture of periphery areas, the paper characterizes the geometries of Shajingzi boundary fault and Wensubei fault detailed-ly, and establishes a geometric and kinematic model with the guidance of fault-related fold theories. The study results suggest that Wensuswell is an inherited upwarping zone controlled by Shajingzi fault, Wensubei fault and basement uplift. Shajingzi fault was developed asfault propagation fold mode at the early stage, then broke through along the forelimb of the fold at the late stage and transtensional faults oc-cured during the late Quaternary. Wensu swell formed at the end of Early Ordovician; its structure was shaped under the influence of theclosing of South Tianshan Ocean at the end of Permian; Wensu swell stepped in relative tectonic silence stage during Mesozoic and stronglydeformed due to the South Tianshan orogenesis during Cenozoic. Wensu swell and the peripheral area are shortened by about 35.40 km to-tally. Fine fault analysis, especially the staged fault analysis can be a breakthrough method to analyze complicated structures.