Deep-Shallow Structures in Tianshan Mountain and Basin-Mountain Coupling Relationship

Tianshan mountain tectonic belt is of a complicated relationship between the deep and shallow structures indicated by the synthetic researches in geology and geophysics.The structures on the south and north sides of Tianshan display obvious symmetry with the axis of Nalun-Nalati-Hongliuhe tectonic suture belt,and it vertically appears in particular spherical structure like a sandwich with rigidity in the top and bottom and the weak in the middle.On the south side of it,it appears that Tarim plate subducts northward intracontinentally,being interbedded to and detached with the lithosphere in Tianshan;in the piedmont Tianshan,the basement is entangled into cap rocks or covers and then deformed.On the north side,Junggar plate enters into Tianshan and has fluxion structures followed by shaping deep piedmont depressions.Therefore,the basin-mountain coupling feature is quite different in the south and north sides of Tianshan mountain.