二叠纪中晚期地质事件对川东北富有机质页岩发育的控制  

Controls of Middle and Late Permian major geological events on the development of the organic-rich shales in northeast Sichuan Basin

作　　者：邓空 陆扬博 张柏林 刘占红 蒙冕模 杜学斌 陈斐然[5] 李飞[5] 陆永潮[1] 苟启洋 王瀚明 DENG Kong;LU Yangbo;ZHANG Bolin;LIU Zhanhong;MENG Mianmo;DU Xuebin;CHEN Feiran;LI Fei;LU Yongchao;GOU Qiyang;WANG Hanming(School of Earth Resources,China University of Geosciences(Wuhan),Wuhan 430074,China;College of Marine Science and Technology,China University of Geosciences(Wuhan),Wuhan 430074,China;State Key Laboratory of Geological Processes and Mineral Resources,China University of Geosciences(Wuhan),Wuhan 430074,China;Institute of Sedimentary Geology,Chengdu University of Technology,Chengdu 610059,China;Research Institute of Geophysics,Exploration Company,China Petroleum&Chemical Corporation,Chengdu 610041,China;School of Geosciences,China University of Petroleum(East China),Qingdao Shandong 266580,China)

机构地区：[1]中国地质大学(武汉)资源学院,武汉430074 [2]中国地质大学(武汉)海洋学院,武汉430074 [3]中国地质大学(武汉)地质过程与矿产资源国家重点实验室,武汉430074 [4]成都理工大学沉积地质研究院,成都610059 [5]中国石化勘探分公司物探研究院,成都610041 [6]中国石油大学(华东)地球科学与技术学院,山东青岛266580

出　　处：《地质科技通报》2025年第2期161-181,共21页Bulletin of Geological Science and Technology

基　　金：国家自然科学基金项目(42072137,42472201,42472197);“地大学者”人才岗位科研启动经费(2023099);国家重大科技专项“大型油气田及煤层气开发”(2022ZC06070001)。

摘　　要：川东北地区二叠系大隆组、吴家坪组和茅口组中3套黑色富有机质页岩获页岩气勘探的重大发现,开辟了接替五峰组-龙一段海相页岩气勘探开发的新领域。基于岩石学、沉积学和地球化学分析,探讨了这3套黑色富有机质页岩的沉积特征及其沉积古环境的演化过程,综合分析了川东北地区二叠纪中晚期富有机质页岩沉积时期的古环境差异及有机质富集的控制因素。结果表明,茅口组、吴家坪组及大隆组富有机质页岩具有强烈的非均质性,其发育控制因素也存在显著差异。其中,茅口组三段沉积期受强上升流、弱火山和弱热液活动影响,气候温暖湿润,伴随有极高的初级生产力、低陆源输入及缺氧硫化的水体条件;吴家坪组二段所对应的沉积环境具备高生产力、低陆源输入、季节性上升流、弱热液活动及间隙硫化-硫化条件的特征;大隆组受强热液、上升流和岛弧火山的影响,其所对应的沉积环境具有高初级生产力、低陆源输入及间隙硫化-硫化条件的特征。研究结果进一步揭示了多重地质事件对富有机质页岩的复杂耦合作用,构建了多重地质事件联控的富有机质页岩成因模式,为海相页岩气勘探有利区提供了理论依据及模型支持。[Objective]Three sets of black organic-rich shales found in the Permian Dalong Formation,Wujiaping Formation,and Maokou Formation in northeastern Sichuan have yielded significant discoveries in shale gas exploration,presenting new opportunities beyond the established Wufeng-Longmaxi marine shale gas plays.[Methods]This study investigated the lithological characteristics and paleoenvironmental evolution of these formations through petrological and geochemical analyses.A comprehensive examination of the depositional environments and the key controlling factors for organic matter enrichment during the deposition of these organicrich black shales from the Middle to Late Permian in northeastern Sichuan has been performed.[Results]The findings demonstrate that the three organic-rich shales exhibit considerable heterogeneity,with distinct controlling factors influencing their development.The sedimentary period of the third member of the Maomao Formation was characterized by strong upwelling,weak volcanic activity,and limited hydrothermal activities.This environment featured a warm and humid climate,extremely high primary productivity,low terrestrial input,and anoxic sulfide water conditions.In contrast,the sedimentary environment of the second member of the Wujiaping Formation was marked by high productivity,low continental source input,seasonal upwelling,weak hydrothermal activity,and interstitial sulfidation-sulfidation conditions and driven by strong hydrothermal fluid,upwelling,and island arc volcanic activity.The sedimentary environment of the Dalong Formation also exhibited high primary productivity,low terrestrial input,and interstitial sulfidation-sulfidation conditions.[Conclusion]The research highlights the complex interactions of multiple geological events on organic-rich shales and constructs a genetic model for these shales influenced by various geological factors.This model provides a theoretical basis and supports the identification of favorable areas for marine shale gas exploration.

关 键 词：地质事件 成因模式 上扬子地区 大隆组 吴家坪组 茅口组 富有机质页岩 二叠纪 

分 类 号：P618.13[天文地球—矿床学]