渤海海域东南部新近纪湖盆萎缩期古生物特征及古环境意义  

NEOCENE PALAEONTOLOGICAL CHARACTERISTICS AND ITS PALEOENVIRONMENT SIGNIFICANCE DURING THE WITHERING PERIOD OF THE LACUSTRINE BASIN IN THE SOUTHEASTERN BOHAI SEA,NORTH CHINA

作　　者：潘文静 杜晓峰 王清斌 田德瑞 王军 刘士磊 PAN Wenjing;DU Xiaofeng;WANG Qingbin;TIAN Derui;WANG Jun;LIU Shilei(Bohai Oil field Research Institute,CNOOC Ltd.Tianjin Branch,Tianjin 30045)

机构地区：[1]中海石油(中国)有限公司天津分公司渤海石油研究院,天津300459

出　　处：《微体古生物学报》2018年第3期238-249,共12页Acta Micropalaeontologica Sinica

基　　金：国家科技重大专项(渤海海域勘探新领域及关键技术研究;编号:2016ZX05024-003)资助~~

摘　　要：渤海海域新近纪普遍发育河流相沉积,近年大量探井揭示渤海海域东南部地区新近系发育湖相、浅水三角洲相以及河流相几种沉积类型。本文对东南部地区新近纪古生物特征展开系统研究,在此基础之上结合丰富的岩心资料总结了渤海海域新近纪湖盆萎缩期河湖过渡带各种典型沉积相类型的古生物分布特征。研究表明:湖相地层古生物门类丰富,发现了藻类,孢粉以及无脊椎动物等类型,化石丰度高,尤其是藻类化石占有重要比重,局部含量达90%以上。三角洲前缘化石门类多,但是丰度较滨浅湖低。三角洲平原相,孢粉较藻类化石含量具有明显优势,尤其是草本植物类型含量高,并且植物碎屑,根系,碳屑常见。河流相化石相对贫乏。在此基础上对渤海海域东南部新近系古环境演化开展研究,结果表明新近纪湖盆萎缩整体呈先扩张再衰退的变化过程,馆陶组中晚期以后湖盆逐渐扩张,到明化镇组下段沉积时期古湖盆最为发育,明化镇组上段时期古湖盆逐渐收缩。The traditional view holds that the Neocene is fluvial facies sediments in Bohai Sea,North China.It is confirmed by a large number of exploratory wells that the Neocene were formed on lacustrine facies,shallow water delta facies and fluvial facies on the southeast of Bohai Sea.The palaeontological characteristics on the southeast of Bohai Sea are discussed in this paper.On this basis,the relationship between distribution disciplinarian of paleontology and sedimentary facies are summarized combined with rich core datas during the withering period of the lacustrine basin.New research shows that abundant algal fossils,sporopollen fossils and invertebrate fossils are found in the lacustrine facies strata.Algal fossils occupy an important proportion of fossil composition which can reach up to 90%.Various fossils are found in the deltaic front facies while the content is lower compared to the lacustrine facies.Deltaic plain facies are characterized by high percentage of herbaceous sporopollen,plant clasts,plant roots and coal.The content of sporopollen is much higher than algae.The type and content of fossils are very poor in the fluvial facies.The results indicate that the ancient lakes expanded gradually during the middle period of Cenozoic（Guantao Formation）.The ancient lakes expanded to the peak at the late stage of Cenozoic（Minghuazhen Formation）,and withered in the Pliocene.The lacustrine basin experienced a process of expansion and withering during the Neogene in the southeastern Bohai Sea.

关 键 词：古生物 新近纪 古湖盆 古环境 渤海海域 

分 类 号：Q91[天文地球—古生物学与地层学]