扬子台地西缘上奥陶统白云岩的时代及分布规律  

AGE AND DISTRIBUTION OF THE UPPER ORDOVICIAN DOLOSTONE ON THE WESTERN MARGIN OF THE YANGTZE PLATFORM

作　　者：龙虹宇 李勇[1] 杨岱林 龚方怡 周力 蒋航 李成龙 王凯[4] 崔雨浓 廖子超 吴荣昌[2] 唐浩[3] 王光旭[2] 魏鑫[2] LONG Hong Yu;LI Yong;YANG Dai Lin;GONG Fang Yi;ZHOU Li;JIANG Hang;LI Cheng Long;WANG Kai;CUI Yu Nong;LIAO Zi Chao;WU Rong Chang;TANG Hao;WANG Guang Xu;WEI Xin(Exploration and Development Research Institute,PetroChina Southwest Oil and Gas Field Company,Chengdu 610041;Key Laboratory of Palaeobiology and Petroleum Stratigraphy,Nanjing Institute of Geology and Palaeontology,Chinese Academy of Sciences,Nanjing 210008;School of Geoscience and Technology,SouthWest Petroleum University,Chengdu 610000;School of Earth and Space Sciences,Peking University,Beijing 100871;College of Geosciences,China University of Petrolum(Beijing),Beijing 102249)

机构地区：[1]中国石油西南油气田公司勘探开发研究院,四川成都610041 [2]中国科学院南京地质古生物研究所,古生物学与油气地层应用重点实验室,江苏南京210008 [3]西南石油大学地球科学与技术学院,四川成都610000 [4]北京大学地球与空间科学学院,北京100871 [5]中国石油大学(北京)地球科学学院,北京102249

出　　处：《地层学杂志》2024年第3期279-292,共14页Journal of Stratigraphy

基　　金：国家自然科学基金(U2344209);中国石油西南油气田公司科研计划(20230301-3);古生物学与油气地层应用重点实验室(213123、20191102);中国科学院战略性先导科技专项(B类)(XDB26000000)共同资助。

摘　　要：扬子台地西缘(康滇、川中和滇黔桂古陆之间)在晚奥陶世沉积了华南板块的浅水相地层,其中一套白云岩相地层因是重要的油气储层而备受关注。近些年,随着我国油气资源勘探和地质基础研究的进一步开展,大量钻井和露头剖面资料显示,这套白云岩相地层不仅沉积在康滇古陆东缘(即大箐组),还出现于川中古陆南缘和滇黔桂古陆北缘。通过野外露头和钻井剖面的综合对比研究,结合生物地层和化学地层资料,本文为这套上奥陶统白云岩的地层年代研究提供了更多的证据,并完善了这套地层的时空分布模式。该白云岩相带主要沿三大古陆(康滇、川中和滇黔桂古陆)边缘展布,以康滇古陆东缘及海湾内发育最好,主要以大箐组和王家河坝组的白云岩(桑比阶顶部—凯迪阶)沉积为特征;而川中古陆南缘和滇黔桂古陆北缘主要发育镇雄组(类型A)白云岩、灰质白云岩和白云质灰岩(凯迪阶下部),且厚度较薄。The Late Ordovician shallow-water sediments occur in the western margin of the Yangtze platform of South China adjacent to the Kangdian,Chuanzhong,and Dianqiangui old lands.Being recognized as important oil and gas reservoirs,the Upper Ordovician(Katian)dolomite facies in the studied area have attracted considerable attention for further oil and gas exploration and geological researches.Studies on a large number of drill cores and outcrops reveal that the dolostone was deposited not only along the eastern margin of the Kangdian old land(i.e.Taching Formation),but also the southern margin of the Chuanzhong old land and the northern margin of the Dianqiangui old land.Based on the bio-and chemo-stratigraphical materials,ages of the dolostones in the studied area are analyzed,and their pattern of the spatio-temporal distribution is discussed in detail.The results show that the dolomite facies are mainly distributed along the margins of the three old lands.In the eastern margin and bay of the Kangdian old land,the dolomite facies are characterized by thick dolostone of the Taching and Wangjiaheba formations(top of the Sandbian to the Katian).In addition,dolostone and dolomitic limestone of the Zhenxiong Formation(Type A,lower Katian),with relatively thin thickness,were deposited in the southern margin of the Chuanzhong old land and the northern margin of the Dianqiangui old land.

关 键 词：白云岩 晚奥陶世凯迪期 华南 大箐组 镇雄组 时空分布 

分 类 号：P534.42[天文地球—古生物学与地层学]