前寒武纪——早古生代沉积岩显微组分分类、成因及演化  

Classification,origins,and evolution of macerals in the Precambrian-Eopaleozoic sedimentary rocks

作　　者：罗情勇 钟宁宁[1,2] 李美俊[1,2] 吴进 Imran Khan 张烨 陈清[4] 叶祥忠 李文浩 纪文明 刘安吉 郝婧玥 姚立朋[1,2,7] 吴嘉 LUO Qingyong;ZHONG Ningning;LI Meijun;WU Jin;Imran Khan;ZHANG Ye;CHEN Qing;YE Xiangzhong;LI Wenhao;JI Wenming;LIU Anji;HAO Jingyue;YAO Lipeng;WU Jia(National Key Laboratory of Petroleum Resources and Engineering,China University of Petroleum(Beijing),Beijing 102249,China;College of Geosciences,China University of Petroleum(Beijing),Beijing 102249,China;Chongqing Institute of Geology and Mineral Resources,Chongqing 400042,China;State Key Laboratory of Palaeobiology and Stratigraphy,Nanjing Institute of Geology and Palaeontology and Center for Excellence in Life and Paleoenvironment,Chinese Academy of Sciences,Jiangsu,Nanjing 210008,China;Geology Team No.107,Chongqing Bureau of Geology and Minerals Exploration,Chongqing 401120,China;School of Geosciences,China University of Petroleum(East China),Qingdao,Shandong 266580,China;Key Laboratory of Environment Change and Resources Use in Beibu Gulf(Nanning Normal University),Ministry of Education,Nanning,Guangxi 530001,China)

机构地区：[1]中国石油大学(北京)油气资源与工程全国重点实验室,北京102249 [2]中国石油大学(北京)地球科学学院,北京102249 [3]重庆地质与矿产研究院,重庆400042 [4]中国科学院,南京地质古生物研究所和生物演化与环境卓越中心,现代古生物学和地层学国家重点实验室,江苏南京210008 [5]重庆市地质矿产勘查开发局107地质队,重庆404100 [6]中国石油大学(华东)地球科学与技术学院,山东青岛266580 [7]南宁师范大学,北部湾环境演变与资源利用教育部重点实验室,广西南宁530001

出　　处：《石油与天然气地质》2023年第5期1084-1101,共18页Oil & Gas Geology

基　　金：国家自然科学基金项目(42122016,41773031,41503028);国家重点研发计划项目(2017YFC0603102)。

摘　　要：前寒武纪—早古生代沉积岩时代古老、生源简单,但有机显微组分面貌却很复杂。通过对大量国内外自然演化和人工熟化系列样品的观察和分析,基于生源、成因、沉积转化及热成熟作用4个主控因素,提出将古老沉积岩的显微组分划分为类镜质组、腐泥组、固体沥青组、动物有机碎屑组和惰质组。低成熟的古老海相烃源岩的显微组分组成以层状藻类体、沥青质体和矿物沥青基质为主;高-过成熟的古老海相烃源岩的显微组分组成以源内固体沥青为主;笔石表皮体常见于五峰组-龙马溪组页岩,是其中有机质的重要组成部分。进一步分析了其中最具特征且以往易被忽视的显微组分的成因,前寒武纪样品中类镜质组颗粒的成因可能为早期成岩过程低等水生生物遭受微生物降解所形成;源内固体沥青为经一次运移残留在烃源岩内的可溶有机质裂解后的固体残留物或者腐泥组残余干酪根吸收同化可溶有机质后的热演化固相产物。通过自然演化系列样品和热模拟样品的综合研究,明确了中国高-过成熟的前寒武纪、寒武纪和奥陶纪—志留纪含笔石页岩有机质的“前世”分别类似于中元古代下马岭组、寒武纪Alum页岩和奥陶纪含笔石Alum页岩有机质的“今生”,提出笔石表皮体、类镜质组颗粒和源内固体沥青反射率都可以用于表征前寒武纪—早古生代海相烃源岩有机质热演化程度。This study delves into the intricate organic macerals found in ancient Precambrian-Eopaleozoic sedimentary rocks,despite their simple biotic sources.Based on the observation and analysis of a vast array of naturally-and artificially-matured rock samples from domestic and international locations,we classify the macerals according to four dominant factors,namely biogenesis,origin,sedimentary transformation,and thermal maturation.The key classe determined include vitrinite-like macerals,sapropelinites,solid bitumen,zooclasts,and inertinites.The macerals in low-maturity marine source rocks are chiefly composed of lamalginite,bituminite,and mineral-bituminous matrix.In contrast,high-to over-mature marine source rocks predominantly contain in-source solid bitumens.Notably,graptolite periderms,as significant components of organic matter,are prevalent in the shales of the Wufeng-Longmaxi formations.We provide deeper insights into the origins of the most typical macerals prone to be overlooked previously,including vitrinite-like maceral particles and in-source solid bitumens.The vitrinite-like maceral particles in the Precambrian rock samples may arise from the microbial degradation of lower aquatic organisms during early diagenesis.In-source solid bitumens form either as solid residues arising from the cracking of soluble organic matter that remained within source rocks after primary migration or as solid-phase products during the thermal evolution of the residual kerogen of sapropelinites after absorbing and assimilating soluble organic matter.Lastly,as indicated by integrated research on the naturally-and artificially-matured rock samples,the preexisting organic matter in high to over mature Precambrian,Cambrian,and Ordovician-Silurian graptolite-bearing shales in China resemble the present-day organic matter in the Mesoproterozoic Xiamaling Formation,Cambrian Alum Shale Formation,and Ordovician graptolite-bearing Alum Shale Formation,respectively.The reflectance of graptolite periderms,vitrinite-like maceral particles

关 键 词：源内固体沥青 笔石表皮体 显微组分 前泥盆纪 有机岩石学 海相烃源岩 页岩 

分 类 号：TE121.3[石油与天然气工程—油气勘探]