东海盆地福州凹陷始新统沟鞭藻生物地层划分与对比  

BIOSTRATIGRAPHY DIVISION AND CORRELATION OF THE EOCENE DINOFLAGELLATE FROM FUZHOU SAG,EAST CHINA SEA BASIN

作　　者：陈忠云 季兴开 姜勇 张涛 徐振中 黄晓松 祝幼华[2] CHEN Zhong Yun;JI Xing Kai;JIANG Yong;ZHANG Tao;XU Zhen Zhong;HUANG Xiao Song;ZHU You Hua(CNO0C China Limited,Shanghai Branch,Shanghai 200335;Nanjing Institute of Geology and Palaeontology,Chinese Academy of Sciences,Nanjing 210008)

机构地区：[1]中海石油(中国)有限公司上海分公司,上海202335 [2]中国科学院南京地质古生物研究所,江苏南京210008

出　　处：《地层学杂志》2024年第4期370-379,共10页Journal of Stratigraphy

基　　金：中海石油(中国)有限公司综合科研项目(KJZH-2023-2103)资助。

摘　　要：福州凹陷FZ-1井位于东海盆地台北坳陷,该井钻遇了侏罗系至新近系,是福州凹陷典型的钻井剖面。通过对FZ-1井始新统沟鞭藻的系统研究,自下而上识别出2个沟鞭藻组合:(1)瓯江组,1410~1535m井段为Wetzeliella meckelfeldensis-Apetodinium donghaiense组合;(2)温州组,1310~1385m井段为Cordosphaeridium gracile-Operculodinium centrocarpum组合。本文根据沟鞭藻特征性分子及与同时期其他地区沟鞭藻组合的对比,认为瓯江组时代为早始新世,温州组时代为中始新世;依据沟鞭藻丰度、分异度及特征性环境指示种,探讨了沉积环境。研究井段沟鞭藻较丰富,总体面貌以收缩式囊孢为主,腔式和贴近式囊孢较少,部分层位含微有孔虫内膜(Microforaminiferal linings),表明研究区早、中始新世为温暖浅海的沉积环境。从早始新世至中始新世,沟鞭藻丰度从低到高再到低,经历了海水深度从浅到深再到浅的变化,反映了一次完整的海侵和海退过程。Well FZ-1 in Fuzhou Sag is located in the Taibei Depression,East China Sea Basin.The well encountered the Jurassic to Neogene and is a typical well section in Fuzhou Sag.This paper reports the dinoflagellates from the Oujiang and Wenzhou formations in Well FZ-1.Base on the characteristics and distribution of dinoflagellate,two dinoflagellate assemblages were recognized,namely Cordosphaeridium gracile-Operculodinium centrocarpum assemblage(Wenzhou Formation,1310-1385 m)and Wetzeliella meckelfeldensis-Apetodinium donghaiense assemblage(Oujiang Formation,1410-1535 m).According to the characteristic species of dinoflagellates and the comparison with dinoflagellates from other regions of the same period,we proposed that the Oujiang Formation is of the Early Eocene age and the Wenzhou Formation is of the Middle Eocene age.The sedimentary environment was discussed based on the abundance,diversity and characteristic environmental indicator species.The study section is rich in dinoflagellates,and the overall appearance is dominated by chorate cysts,with fewer proximate and cavate cysts.Some strata contain microforaminiferal linings,indicating that the study area was a warm shallow marine sedimentary environment in the Early and Middle Eocene.From the Early Eocene to the Middle Eocene,the abundance of dinoflagellates changed from low to high and then to low,and the sea depth changed from shallow to deep and then to shallow,reflecting a complete process of transgression and regression.

关 键 词：沟鞭藻 生物地层 始新统 福州凹陷 东海盆地 

分 类 号：P534.61[天文地球—古生物学与地层学]