东海盆地石门潭组属于裂陷期地层序列吗?  

IS SHIMENTAN FORMATION IN THE EAST CHINA SEA BASIN A SYN-RIFTING SUCCESSION?

作　　者：覃军 熊萍 何新建 沈冠华 王瑞霞[5] 梅廉夫[4] 吕志欢 叶青[4] QIN Jun;XIONG Ping;HE Xin Jian;SHEN Guan Hua;WANG Rui Xia;MEI Lian Fu;LU Zhi Huan;YE Qing(CNO0C China Limited,Shanghai Branch,Shanghai 200335;National Science Library(Wuhan),Chinese Academy of Sciences,Wuhan 430071;Hubei Key Laboratory of Big Data in Science and Technology,Wuhan 430071;Key Laboratory of Tectonics and Petroleum Resources(China University of Geosciences),Ministry of Education,Wuhan 430074;Geophysical Research Institute,Zhongyuan Oilfield Company,SINOPEC,Puyang 457001;Daqing Oilfield Co.,Ltd.Chengdu Exploration and Development Research Institute,Chengdu 610051)

机构地区：[1]中海石油(中国)有限公司上海分公司,上海200335 [2]中国科学院武汉文献情报中心,湖北武汉430071 [3]科技大数据湖北省重点实验室,湖北武汉430071 [4]中国地质大学(武汉)构造与油气资源教育部重点实验室,湖北武汉430074 [5]中国石化中原油田分公司物探研究院,河南濮阳457001 [6]大庆油田有限责任公司成都勘探开发研究院,四川成都610051

出　　处：《地层学杂志》2024年第4期380-391,共12页Journal of Stratigraphy

基　　金：湖北省自然科学基金创新群体项目(2021CFA031);中海石油(中国)有限公司重大科技项目(KJGG2022-0301)共同资助。

摘　　要：东海盆地裂陷期旋回演化对探索晚中生代以来西太平洋俯冲体系演变及伸展盆地油气富集规律具有重要意义。过去常认为石门潭组含火山岩夹层或火山碎屑岩的沉积序列记录了东海盆地初始裂陷期的构造与沉积格局,但石门潭组在空间上表现出很强的非均一性,与上下地层的继承或转折关系尚未得到科学论证。论文在系统梳理区域资料基础上,利用最新采集的三维/二维地震、测录井和年代学数据,对这一重要问题展开了研究。结果表明:在岩石学上石门潭组是一套包含基性岩(玄武岩)到酸性岩(英安岩)的广谱杂色岩系,且在不同的凹陷呈现显著差别;在地震反射特征上石门潭组在丽水—椒江凹陷表现为残留的丘状反射,在钱塘和福州凹陷表现为连续的碟状或层状反射且与下伏中生代地层整合接触,在西湖凹陷则具有楔状反射特征且与上覆新生代地层整合接触;在年代学特征上石门潭组在丽水和福州凹陷形成于晚白垩世末(70—75Ma),在西湖凹陷的形成时代可能始于早白垩世。基于上述结果,本文认为石门潭组表现出更强的中生代构造—沉积旋回的继承性特征。东海盆地大规模的陆壳伸展减薄和破裂应当发生在晚白垩世之后。The evolution of the rift cycle in the East China Sea Basin is of great importance for understanding the change of the western Pacific subduction system since the late Mesozoic and the law of petroleum accumulation in the extensional basin.Normally,it was argued that the Shimentan Formation,containing volcanic interlayers or pyroclastic rocks,recorded the tectonic configuration and sedimentary pattern of the initial rift period of the East China Sea Basin.However,the Shimentan Formation showed strong heterogeneity in space,and the inheritance or transition relationship between the Shimentan Formation and its upper and lower strata has not been scientifically demonstrated.Based on systematic regional data,this research focuses on this important issue by using the newly acquired three-and two-dimensional seismic datasets,core-drilling and logging data,and bulk-rock/single-mineral chronological data.Results show that the Shimentan Formation is a broad-spectrum heterogeneous rock succession consisting of basic rocks(basalt)to acid rocks(dacite),and there are significant differences in different depressions.In seismic reflection characteristics,the Shimentan Formation shows residual hummocky reflection in Lishui-Jiaojiang Sag,continuous disc-like or stratified reflection in Qiantang and Fuzhou Sags and conformity contact with the underlying Mesozoic strata,and cuneiform reflection in Xihu Sag and conformity contact with the overlying Cenozoic strata.In chronology,the Shimentan Formation in Lishui and Fuzhou Sags was formed at the end of the Late Cretaceous(~70-75 Ma),but in Xihu Sag,its formation age may start in the Early Cretaceous.In this context,we conclude that the Shimentan Formation shows a stronger Mesozoic tectono-sedimentary cycle inheritance.The large-scale continental crust thinning and rupture in the East China Sea Basin should occur after the Late Cretaceous.

关 键 词：伸展盆地 石门潭组 东海盆地 俯冲体系 前裂陷期 

分 类 号：P534.53[天文地球—古生物学与地层学]