乌伦古坳陷位于准噶尔盆地的东北缘,中生代以来逆冲断裂特别发育。本文通过对典型二维地震剖面进行构造解释,结合平衡剖面的正演方法,对乌伦古坳陷内逆冲推覆构造的分带性、分期性和拓展方式及动力过程进行研究。研究认为乌伦古坳陷内部逆冲推覆构造从北向南分为根部带的红岩断阶带、中部带的索索泉凹陷、前锋带的喀拉萨依断裂。剖面平衡结果显示,从晚三叠世到白垩纪,准噶尔盆地东北缘受到自北向南的挤压作用,逆冲断裂整体表现出基底卷入的前展式叠瓦逆冲的特点,具有从北向南拓展规律,即北部断裂活动较早,而南部断裂活动较晚。对比平衡剖面不同时代地层的收缩率变化可知,逆冲断裂活动总体可以划分为4个演化阶段:印支末期、燕山早期、燕山中期和燕山晚期。其中印支期是逆冲体系的启动期;燕山早期为主活动期,逆冲活动波及全区;燕山中期逆冲活动表现为震荡特征;燕山晚期逆冲活动微弱。中生代前期,乌伦古坳陷地区的逆冲体系形成的动力主要来自南阿尔泰造山带持续挤压,中生代后期叠加了北天山造山带自南向北的推覆挤压,使坳陷南部喀拉萨依断裂具有了走滑性质,该走滑活动与准噶尔内部微块体之间发生挤出-逃逸的调节过程有关。 The Ulungu Depression is located in the northeastern margin of the Junggar Basin and has been particularly developed since the Mesozoic. In this paper, the tectonic interpretation of the typical two-dimensional seismic profile and the forward modeling of the balanced profile are carried out to study the zonation, staging, expanding modes and dynamic processes of the thrust nappe structure in the Wulungu Depression. The study suggests that the internal thrust nappe structure in the Ulungu Depression is divided into the red rock fault zone in the root zone from the north to the south, the Soxhuanquan depression in the central zone and the Karasayi fault in the foreland zone. The results of section balance show that from the Late Triassic to the Cretaceous, the northeastern margin of the Junggar Basin is squeezed from north to south, and the thrust faults as a whole show the characteristics of the foreground imbricate thrust imbedded in the basement. South expansion of the law that the northern fault activity earlier, while the southern fault activity late. Comparing the shrinkage changes of different age strata in equilibrium sections, it can be seen that the thrust activities can be divided into four stages: the end of Indosinian period, the early Yanshanian period, the middle Yanshanian period and the late Yanshanian period. The Indosinian period is the start-up period of the thrust system; the early Yanshanian period is the main activity period, and the thrust activity extends to the whole area; the mid-Yanshanian thrust activity is characterized by turbulence; and the late Yanshanian thrust activity is weak. In the early Mesozoic, the thrust of the thrust system in the Wulungu Depression mainly came from the continuous extrusion of the Southern Altay orogen, and from the south to the north of the North Tianshan orogenic belt superimposed by the Late Mesozoic, Due to the strike-slip nature of the fault, the strike-slip activity is related to the process of extrusion-escalation occurring within the microliths in Junggar.