川中地区大安寨段分子标志物异常组合及其地球化学意义  

An abnormal assemblage of molecular markers and its geochemical significance in the Da'anzhai Member of the central Sichuan Basin

作　　者：杨孝勇 唐友军 洪海涛[3] 王小娟[3] 吴长江[3] 张吉振[1,2] 黄亚浩 李美俊 卢晓林[4] 裴冰冰[1,2] YANG Xiaoyong;TANG Youjun;HONG Haitao;WANG Xiaojuan;WU Changjiang;ZHANG Jizhen;HUANG Yahao;LI Meijun;LU Xiaolin;PEI Bingbing(Hubei Key Laboratory of Petroleum Geochemistry and Environment(College of Resources and Environment,Yangtze University),Wuhan 430100,Hubei,China;Key Laboratory of Exploration Technologies for Oil and Gas Resources(Yangtze University),Ministry of Education,Wuhan 430100,Hubei,China;Exploration and Development Research Institute,Petro China Southwest Oil&Gasfield Company,Chengdu 610041,Sichuan,China;State Key Laboratory of Petroleum Resources and Prospecting,College of Geosciences,China University of Petroleum,Beijing 102249,China)

机构地区：[1]油气地球化学与环境湖北省重点实验室(长江大学资源与环境学院),湖北武汉430100 [2]油气资源与勘探技术教育部重点实验室(长江大学),湖北武汉430100 [3]中国石油西南油气田分公司勘探开发研究院,四川成都610041 [4]油气资源与探测国家重点实验室,中国石油大学(北京)地球科学学院,北京102249

出　　处：《地质通报》2022年第4期669-681,共13页Geological Bulletin of China

基　　金：国家自然科学基金项目《苯基多环芳烃检测及其石油地球化学意义》(批准号:41972148)。

摘　　要：在川中地区大安寨段烃源岩抽提物中检测出丰富的重排藿烷系列、重排补身烷系列、重排甾烷系列及C_(26+)长链三环萜烷系列的分子标志物组合。结合烃源岩的有机质来源、沉积环境、热演化程度特征,探讨上述甾烷、萜烷分布特征指示的地质地球化学意义。结果表明:重排类化合物与C_(26+)长链三环萜烷系列存在着某些相同的富集途径,重排藿烷系列富集途径多于重排补身烷系列、重排甾烷系列及C_(26+)长链三环萜烷系列;特殊的甾烷、萜烷分布特征指示,烃源岩中有机质以湖泊内源(藻类和细菌等)为主,形成于范围局限的弱还原环境,高丰度的重排化合物指示,有机质热演化处于成熟阶段。此外,特殊的甾烷、萜烷分布特征还可能指示了特定的酸性粘土矿物、钙质沉积催化和形成环境中发育的特殊生物族群。综上,研究结果对分子标志物异常组合的地球化学应用具有重要的示范意义。An abnormal assemblage of molecular markers was found in the source rock extracts from the Da'anzhai Member in the central Sichuan Basin,including extremely rich in rearranged hopanes,rearranged drimanes,rearranged steranes and C_(26+)long-chain tricyclic terpanes.Integrated with the organic matter source,depositional environment and source rock maturity,the significance of the above-mentioned special steranes and terpenes assemblages is discussed.The results show that rearranged compounds and C_(26+)long-chain tricyclic terpanes have the similar enrichment pathways,among which the enrichment pathway of rearranged hopanes is more than that of rearranged drimanes,rearranged steranes and C_(26+)long-chain tricyclic terpanes.The special assemblages of steranes and terpenes may indicate that the organic matter is mainly contributed by lagoonal autochthonous sources(algae and bacteria,etc.)and formed in a restricted weakly reduction environment.The high abundance of rearranged compounds indicate that the organic matter has been thermally mature.In addition,it may indicate specific acidic clay minerals and calcareous sediments catalysis and special biotic community in the depositional environment.In summary,this study has an important demonstration significance for the geochemical application of abnormal assemblages of molecular markers.

关 键 词：分子标志物异常组合 大安寨段 有机质来源 沉积环境 热演化程度 四川盆地 

分 类 号：P618.13[天文地球—矿床学]