塔里木盆地轮南潜山构造特征

STRUCTURAL FEATURES OF THE BURIED HILL IN LUNNAN AREA OF TARIM BASIN

轮南潜山的地质构造在奥陶系碳酸盐岩地层的顶部表现最清晰 ,为一个走向北东而向南西倾伏的非对称背斜 ,背斜中段轴部和东南翼发育 4条近东西走向的主干断裂及其控制的 2条挤压断垒带。笔者利用构造解析和力学分析方法 ,在两断垒带之间的中部平台区揭示出数条不同走向的小断裂密集带 (断裂带 )。其中 ,2条北东向断裂带斜贯中部平台区 ,4条北西向断裂带与之网状交织 ,2条南北向断裂带穿插于其间 ,它们与主干断裂一起构成轮南潜山的构造格局。这是在晚华力西—印支期近南北向挤压作用下产生的由压、剪、张性破裂组成的一套完整的构造变形组合。

The geological structures of a buried hill appear clearly on the top of the Ordovician carbonate strata in Lunnan area of Tarim Basin.The structural zone is an asymmetric anticline of NE trending and SW dipping.Along the axis part of the middle anticline and its southeastern flank,there are 4 major faults of roughly EW strike and 2 associate compressive fault_anticline zones.By using the structural and mechanical analysis methods,several concentrating zones of small faults with different strikes between the two fault_anticline zones in the middle platform area are revealed.Among them,two faults with NE trending extend obliquely through the middle plantform,with which 4 faults with NW trending are intersecting in a shape of network,and two faults with NS trending are intercalated with them.Together with the major faults,these zones constitute the tectonic framework of the Lunnan buried hill,which is a complete set of deformations including compressive,shear and tensional fractures caused by the nearly NS directional compression during the late Variscan_Indo_China period.