川东齐岳山断层北部差异构造变形特征

根据地震资料结合区域地质资料，对川东齐岳山断层构造几何学和运动学特征及断层演化史进行了分析。齐岳山断层自北往南剖面形态上依次表现为“y”字形、“之”字形和铲形，地表出露断层倾向从北西变为南东；断层具有明显的分段式结构，断层西侧周缘构造样式自北向南由“巫山-吐祥段的隐冲加断滑褶皱”至“吐祥-忠县段的断展加滑脱褶皱”至“忠县-焦石坝段的基底冲断-断展褶皱”至“焦石坝-南川段的冲断褶皱”，断层东侧周缘则整体表现为冲断构造变形；齐岳山断层形成于早燕山期，之后又经历了燕山运动中期的挤压作用与燕山运动晚期的伸展作用，以断层中段变形程度最强。齐岳山断层差异构造变形导致断层两侧油气保存条件明显不同，断层周缘二级台阶构造形态呈铲形处为有利油气勘探区。 

Differential tectonic deformation in the northern Qiyueshan Fault,eastern Sichuan Basin

The geometrical and kinematic characteristics and fault evolution history of the Qiyueshan Fault were analyzed systematically using seismic and geological data. The profile morphology of the Qiyueshan Fault from north to south shows in turn a “Y”, “zigzag” and spade shape. The exposed fault inclination changes from northwest to southeast. The Qiyueshan Fault is characterized by a sectional structure. The structural pattern of the western periphery of the fault, from north to south, changes from “hidden thrust and fault-slip fold of the Wushan-Tuxiang segment” to “fault-spread and slip fold of the Tuxiang-Zhongxian segment”, to “basement thrust-fault-spread fold of the Zhongxian-Jiaoshi segment”, to “thrust fold of the Jiaoshi-Nanchuan segment”. The eastern periphery of the fault is characterized by thrust structural deformation. The Qiyueshan Fault was formed in the Early Yanshanian stage, and then underwent extrusion in the middle Yanshanian Movement and extension in the late Yanshanian Movement. The middle section of the fault is the most deformed. Different structural deformations lead to the obvious difference of oil and gas preservation conditions on both sides of the fault.