摘要:以地震、钻井资料为基础，结合构造地质横剖面特征，应用断层相关褶皱理论，探讨沙湾凹陷及其邻区石炭—二叠纪伸展断陷构造的几何学特征；在此基础上，通过计算地层生长指数、反转率，进一步揭示沙湾凹陷及其邻区石炭—二叠纪构造运动学特征及形成演化过程。研究认为：1） 沙湾凹陷及其邻区石炭—二叠纪共发育16 条断层，其中5 条正断层、6 条逆断层、5 条断层具备下正上逆特征；2） 沙湾凹陷及其邻区晚石炭世—早二叠世处于南北向挤压、东西向张裂的伸展断陷环境，早二叠世晚期风城组（P1f）沉积之后，该区域构造环境转变为北西—南东向挤压环境，部分先存正断层发生反转，形成一系列隐伏的隆起区；3） 通过计算地层生长指数和部分断层的反转率，认为研究区西北部地层生长指数和断层反转率普遍较高，研究区南部地层生长指数和断层反转率相对较低，即研究区西北部晚石炭世—早二叠世受伸展构造活动影响较为强烈，早二叠世末期受构造改造较为明显，研究区南部基本保持早期伸展断陷构造样式。
关键词: 沙湾凹陷/
伸展构造/
石炭—二叠纪/
地层生长指数/
反转率/
构造演化
Abstract:Geometry characteristics of extensional fault depression in Shawan sag and its adjacent area: Carboniferous-Permian are discussed in detail with the theory of fault-related fold by combining the characteristics of the cross section of tectonic geology based on seismic and drilling data; then the stratum growth index and inversion rate are calculated on this basis, which further reveals the kinematic characteristics and formation evolution process of construction of Shawan sag and its adjacent area: Carboniferous-Permian. It is concluded from the research that Shawan sag and its adjacent area: A total of 16 faults are recognized in Shawan sag and its adjacent: Carboniferous-Permian, among them, 5 normal faults, 6 thrust faults and 5 early normal faults have been reversed; Medium-Late Carboniferous-Early Permian in Junggar Basin are the extensional fault depression environment of north-south extruding and west-east stretching, the Early Permian-Late Fengcheng group is changed into the NW-SE compression environment after deposition, some of the early normal faults reverse and form a series of insidious uplift zones; It can be drawn from the calculation of stratum growth index and the inversion rate of sectional tectonic units that the growth index of stratum in northwestern margin and the inversion rate of structural units are generally higher in the study area, and the southern margin in the study area are relatively low.
Key words:Shawan sag/
Extensional structure/
Carboniferous-Permian/
Growth-index/
Inversion ratio/
Tectonic evolution
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