四川盆地西南部多期叠加变形构造解析:以自流井背斜为例  

Structuralanalysis of multi-stage superimposed deformation in the southwestern Sichuan Basin:An example from the Ziliujing anticline

作　　者：熊小林 张金武 孟也 花吉清 程辉 陈志宇 尹超 刘嘉伟 杨文雄 钟雅琪 饶刚[2,3] XIONG Xiaolin;ZHANG Jinwu;MENG Ye;HUA Jiqing;CHENG Hui;CHEN Zhiyu;YIN Chao;LIU Jiawei;YANG Wenxiong;ZHONG Yaqi;RAO Gang(CNPC Greatwall Drilling Company,Panjin 124010,Liaoning,China;School of Geoscience and Technology,Southwest Petroleum University,Chengdu 610500,Sichuan,China;CPCIF Key Laboratory of Oil and Gas Geophysical Exploration Technology in Foothill Belts,Southwest Petroleum University,Chengdu 610500,Sichuan,China)

机构地区：[1]中国石油集团长城钻探工程有限公司,辽宁盘锦124010 [2]西南石油大学地球科学与技术学院,四川成都610500 [3]西南石油大学石油和化工行业山前带油气地球物理勘探技术重点实验室,四川成都610500

出　　处：《地质通报》2024年第10期1788-1800,共13页Geological Bulletin of China

基　　金：四川省自然科学基金面上项目《宜宾地区柏树溪断裂构造分析及其地震风险指示意义》(批准号:2022NSFSC0212);自然资源部深地科学与探测技术实验室开放课题《川南构造叠加区断裂模型构建及其地震指示意义》(编号:SinoProbe Lab 202213)。

摘　　要：四川盆地西南部地区由于受到周缘造山带构造隆升及变形扩展作用的影响,构造变形样式复杂,演化期次缺乏准确的时间约束。为了进一步探究该地区的构造演化过程,本次研究选取构造变形幅度相对较小的自流井背斜为研究对象,基于高品质地震反射资料,依据断层相关褶皱理论,精细解析其构造几何样式和运动学特征。研究结果表明,区内构造变形分层特征明显,深部以寒武系膏盐层为滑脱层,发育断层传播褶皱和滑脱褶皱,中部逆冲褶皱变形主要限制在志留系泥页岩顶界不整合面和下三叠统膏盐岩滑脱层之间,而浅部主要在上三叠统及以上地层发育宽缓褶皱和局部小位移断层。其中,深部寒武系滑脱层对区域构造样式控制起到关键作用。识别出的生长地层及构造平衡恢复结果揭示,自流井背斜带主要经历了加里东期、印支期,以及燕山期—喜马拉雅期3期主要挤压构造变形。而上三叠统中发育的北西向断裂指示后期在不同方向构造应力场下发生了叠加变形,可能是受到青藏高原东缘往东向四川盆地扩展作用的影响。Due to the tectonic uplift and deformation propagation of adjacent orogens,complex structural styles have developed in thesouthwestern Sichuan Basin.However,there is still a lack of precise age constraints on their evolution history.Based on high−qualityseismic reflection data,we conduct a structural analysis on the structural geometry and kinematic features of the low−amplitudeZiliujing anticline as an example using fault−related folding theory for exploring the history of structural evolution in the study area.The results demonstrate distinct stratified tectonic deformation.In the deep,fault−propagation folds and detachment folds developabove the Cambrian salt.Folds and thrusts in the intermediate are primarily confined between the top of the Silurian shales and soils and the lower Triassic salt layer.In the shallow,it is primarily characterized by gentle folds and minor faults.Significantly,the regionalstructural styles in this area are controlled by the deep Cambrian detachment.The identified growth strata,in conjunction with theresults of balanced structural restorations,indicate that the study area has undergone three main stages of tectonic compression;lateCaledonian,Indosinian,and Yanshanian and Himalayan epochs.Furthermore,the development of NW−directed faults in the upperTriassic strata implies a structural imposition likely resulting from the propagation of deformation due to eastward movement of theeastern margin of the Tibetan Plateau.

关 键 词：多期叠加变形 生长地层 滑脱层 断层相关褶皱 四川盆地西南部 

分 类 号：P542[天文地球—构造地质学]