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形成于中新生代的南天山库车山前坳陷带和北天山乌鲁木齐山前坳陷带表现出类似的几何学、运动学和动力学特征 ,即坳陷内都发育 4排近东西向展布的逆断裂 -背斜带 ;新生代 (特别是第四纪以来 )表现出强烈的由山体向盆地的逆冲活动 ;逆断裂 -背斜带的形成、演化和发展都受控于统一的近南北向构造应力场。然而 ,南北两个山前坳陷在变形强度、地球物理细结构、地球动力学环境等方面存在着明显的不同。对这些不同点进行了讨论 ,认为正是这些不同点的存在 ,使得天山南北两侧山前坳陷内的现今地震活动性显示出不对称性 ,即南天山库车山前坳陷 5级以上地震基本都分布在第 3排 (秋里塔格 )逆断裂 -背斜带上 ,而北天山乌鲁木齐山前坳陷 5级以上地震基本都分布在坳陷南部准噶尔南缘断裂附近及其以南的天山内部。
The Mesozoic-Cenozoic Kuqa piedmont belt in the southern Tianshan Mountains and the Urumqi piedmont belt in the northern Tianshan Mountains show similar geometric, kinematic and kinetic characteristics, ie 4 rows of near east-west development The reverse thrust-anticline belt of the cloth; the Cenozoic (especially since the Quaternary) showed a strong thrust from the mountain body to the basin; the formation, evolution and development of the reverse fault-anticline zone are controlled by the unified Near North-South tectonic stress field. However, there are obvious differences in deformation strength, fine geophysical structure and geodynamic environment between the two piedmont potholes. These differences are discussed and it is considered that the existence of these differences makes the present-day seismicity in the Piedmont Depression on both sides of the Tianshan Mountain show an asymmetry, ie, the grade 5 of the Kuqa piedmont depression in the southern Tianshan Mountains The earthquakes are basically distributed in the reverse fault-anticline belt in the third row (Qiu Litang), while the earthquakes above the magnitude 5 in the Urumqi piedmont piedmont of the North Tianshan are basically distributed near the southern margin of Junggar in the southern margin of the depression and south of it Tianshan interior.