济阳坳陷富有机质页岩记录的中始新世气候适宜期古气候  

PALEOCLIMATE OF THE MIDDLE EOCENE CLIMATIC OPTIMUM RECORDED IN ORGANIC-RICH SHALE IN THE JIYANG DEPRESSION

作　　者：郭颖 马义权 刘惠民[5] 陆永潮[6] 张晨 马超[1,2,3,7] GUO Ying;MA Yiquan;LIU Huimin;LU Yongchao;ZHANG Chen;MA Chao(Key Laboratory of Deep-time Geography and Environment Reconstruction and Applications of Ministry of Natural Resources,Chengdu University of Technology,Chengdu 610059,Sichuan;State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation,Chengdu University of Technology,Chengdu 610059,Sichuan;Institute of Sedimentary Geology,Chengdu University of Technology,Chengdu 610059,Sichuan;College of Management Science,Chengdu University of Technology,Chengdu 610059,Sichuan;SINOPEC Shengli Oilfield Company,Dongying,257000,Shandong;College of Earth Resources,China University of Geosciences(Wuhan),Wuhan 430074,Hubei;College of Computer Science and Cyber Security,Chengdu University of Technology,Chengdu 610059,Sichuan)

机构地区：[1]成都理工大学自然资源部深时地理环境重建与应用重点实验室,四川成都610059 [2]成都理工大学油气藏地质及开发工程全国重点实验室,四川成都610059 [3]成都理工大学沉积地质研究院,四川成都610059 [4]成都理工大学管理科学学院,四川成都610059 [5]中国石油化工股份有限公司胜利油田分公司,山东东营257001 [6]中国地质大学(武汉)资源学院,湖北武汉430074 [7]成都理工大学计算机与网络安全学院,四川成都610059

出　　处：《第四纪研究》2024年第5期1273-1281,共9页Quaternary Sciences

基　　金：国家自然科学基金项目(批准号:42172181和42072137);四川省自然科学基金项目(批准号:2022NSFSC1075);四川省天然气成藏物质基础青年科技创新团队基金项目(批准号:2022JDTD0004);四川省科技计划项目(批准号:2023NSFSC1986)共同资助。

摘　　要：中始新世气候适宜期(MECO)是发生在约40.5~40.1 Ma的一次全球增温事件。目前该事件在海相环境中的响应特征已相对明晰,而对其发生前、发生期间、发生之后的陆相环境响应及差异的认识仍需进一步研究。济阳坳陷北部的沾化凹陷中始新统沙三下亚段(Es3L)为一套富有机质页岩层系,沉积连续,不仅是该区页岩油勘探的重点层位,也为开展MECO事件的陆相环境响应研究提供了详实的沉积记录。本研究利用沾化凹陷Luo69井跨越Es3L且长度约194 m的高分辨率伽马(GR)数据,开展旋回地层学分析,结合相关系数法(COCO)和演化相关系数法(eCOCO),以Es3L的底界年龄41.21 Ma为锚点,建立天文年代标尺。在此基础上,综合Fe含量、Ti/K比值、V/Al比值、TOC含量以及济阳坳陷南部东营凹陷的FY1井的磁性地层,确定MECO事件在研究区的响应时间,查明MECO事件发生前、发生期间、发生后济阳坳陷的气候和水文变化及其对有机质富集的影响。结果表明,Luo69井GR数据中的20.7~27.7 m波长代表405 ka长偏心率,通过调谐,获得GR数据的延续时间为3.34 Ma,Es3L的延续时间为2.48 Ma,与已报道的FY1井结果一致。结合年龄锚点,建立了41.77 Ma至38.43 Ma的天文年代标尺,并推定MECO事件在济阳坳陷的响应时间约为40.51~40.06 Ma,对应于Luo69井的约3045~3017 m区间。在MECO事件发生之前,气候潮湿-干旱波动较大,引起湖盆流域水动力和湖水氧化还原状态出现较大变化;MECO期间,气候更加潮湿,使得流域水动力增强,导致湖水富氧,但该时期TOC含量整体较高,可能与较高的初级生产力有关;在MECO事件发生后,气候变化幅度较小,相对稳定,相比事件发生前更加潮湿,TOC较事件发生前略有升高,主要受控于升高的初级生产力。The Middle Eocene Climatic Optimum(MECO)was a global warming event that occurred at about 40.5~40.1 Ma.At present,the response characteristics of this event in the marine environment are relatively clear,while the understanding of the response and differences in the terrestrial environment before,during,and after the occurrence of this event still needs further study.The lower third Member of the Shahejie Formation(Es3L)in the Zhanhua sag of the Jiyang Depression is a set of organic-rich shale succession with continuous deposition,which is not only a key layer for shale oil exploration in this area,but also provides a detailed sedimentary record for the study of the response of the terrestrial environment to the MECO event.In this study,high-resolution gamma(GR)data from the Luo69 well in the Zhanhua sag,which spans the Es3L and has a length of about 194 m,are used to carry out the cyclostratigraphy analysis,combining the correlation coefficient method(COCO)and the evolutionary correlation coefficient method(eCOCO),to establish an astronomical time scale with the base age of the Es3L of 41.21 Ma as an anchor point.On this basis,Fe content,Ti/K ratio,V/Al ratio,and TOC content of the Luo69 well,and magnetostratigraphy of the FY1 well are integrated to determine the response time of the MECO event in the study area,and to identify the climatic and hydrological changes in the Jiyang Depression before,during,and after the MECO event and their effects on organic matter enrichment.The results show that the 20.7~27.7 m wavelengths in the GR data of Luo69 well represent 405 ka long eccentricity,and the duration of 3.34 Ma for GR data and 2.48 Ma for Es3L is obtained through tuning,which is consistent with the reported results of FY1 well.Combined with the anchor point,an astronomical time scale from 41.77 Ma to 38.43 Ma was established,and the response time of the MECO event in the Jiyang Depression was inferred to be about 40.51~40.06 Ma.Before the MECO event,the climate fluctuated from humid to arid largely in this per

关 键 词：增温事件 统计调谐 时间序列分析 古气候 有机质富集 页岩油 

分 类 号：P534.621[天文地球—古生物学与地层学] P539.2[天文地球—地质学] P595