摘要
麻黄山西工区位于鄂尔多斯盆地西缘冲断带的前端部位,以石炭—二叠系煤系滑脱层为界划分为上、下两套构造变形层,并受燕山期走滑断层作用表现出分段变形特征。深层原地构造系统沙窝子断层以北的正断层构成多米诺组合型式,而沙窝子与圈湾子断层之间的正断层组合成堑垒式。浅层逆冲推覆构造系统以NEE向芦沟子—新泉井断层为界,划分为变形特征差异明显的南、北两段,北段相对南段变形强烈。三维离散元数值模拟实验结果显示,麻黄山西工区上、下构造变形层内发育的走滑断层均为调节差异挤压作用形成的撕裂断层,断层走向与挤压应力方向基本一致。原地构造系统的先存正断层在走滑作用下产生牵引,邻近走滑断层的正断层走向发生明显偏转。逆冲推覆构造系统北段山前强烈冲断作用对盆内产生较为明显影响;而南段山前冲断作用并未对盆内产生明显影响,仅发育少量小规模逆断层。相较于二维模拟,三维模拟能够实现平面与剖面的综合分析,完整认识上、下构造变形层多条走滑断层的变形过程与形成机制,为麻黄山西工区的油气勘探提供基础地质理论指导。
The western Mahuangshan work area,located in the front of thrust belt in the western margin of the Ordos Basin,is divided into the upper and lower structural deformation layers by taking the Carboniferous-Permian coal detachment layer.It is also characterized by segmentation deformation due to the Yanshanian strike-slip faulting.The normal faults north of the Shawozi fault in the deep in-situ structural system formed domino type,while the normal faults between the Shawozi fault and the Quanwanzi fault formed graben-horst type.The shallow thrust-nappe structural system,bounded by the NEE trending Lugouzi-Xinquanjing fault,can be divided into the southern and northern sections with obvious different deformation characteristics.The deformation in the northern section is stronger than that in the southern section.Three-dimensional discrete element simulation results show that the strike-slip faults developed in the upper and lower structural deformation layers in the western Mahuangshan work area are tear faults formed by regulating differential compression,and the fault strikes are mainly consistent with the direction of maximum compressional stress.The pre-existing normal faults in the deep in-situ structural system were dragged by the strike-slip faulting,and strikes of the normal faults adjacent to the strike-slip faults were obviously deflected.The strong piedmont thrusting in the northern section of the thrust-nappe structural system had obvious impact on the basin.However,the piedmont thrusting in the southern section had no obvious impact on the basin,and only a few small-scale reverse faults were developed.Compared with 2D simulation,3D simulation can analyze the strike-slip faults in the plane and section,give us a full view of the deformation process and formation mechanism of the strike-slip faults within the upper and lower structural deformation layers,and provide basic geological guidance for the oil and gas exploration.
作者
罗良
贾会冲
杨明慧
刘雅蓉
黎小伟
杨飞
刘志娜
白东来
Luo Liang;Jia Huichong;Yang Minghui;Liu Yarong;Li Xiaowei;Yang Fei;Liu Zhina;Bai Donglai(State Key Laboratory of Petroleum Resources and Prospecting,China University of Petroleum(Beijing),Beijing 102249;College of Geosciences,China University of Petroleum(Beijing),Beijing 102249;North China Company,SINOPEC,Zhengzhou 450006)
出处
《地质科学》
CAS
CSCD
北大核心
2023年第4期1210-1225,共16页
Chinese Journal of Geology(Scientia Geologica Sinica)
基金
中国石化科技部项目群课题4(编号:P20062-4)资助。
关键词
鄂尔多斯盆地西缘
麻黄山西
三维数值模拟
走滑断层
差异挤压
Western margin of the Ordos Basin
Western Mahuangshan
3D numerical simulation
Strike-slip fault
Differential compression
