华南上扬子区中奥陶世(达瑞威尔期)十字铺组与牯牛潭组的划分与时空分布  

Middle Ordovician (Darriwilian) Shihtzupu (Shizipu) and Guniutan Formations in the Upper Yangtze Region,South China

作　　者：樊茹[1,2,3,4] 邓胜徽[1,2,3] 张学磊[1] 张师本[1] 卢远征[1,2,3] 李鑫[1,2,3] 

机构地区：[1]中国石油勘探开发研究院,北京100083 [2]提高采收率国家重点实验室,北京100083 [3]中国石油天然气集团公司油气储层重点实验室,北京100083 [4]中国科学院南京地质古生物研究所,南京210008

出　　处：《地质论评》2015年第4期735-742,共8页Geological Review

基　　金：中国石油天然气股份有限公司重大科技项目"油气勘探新领域;新理论;新方法;新技术研究"之06课题;中国科学院南京地质古生物研究所博士后工作站项目的成果

摘　　要：笔者等在充分调研的基础上,通过开展大量的野外勘察以及牙形石生物地层研究,结合露头和钻井资料对上扬子区中奥陶世牯牛潭组与十字铺组的定义与时空分布特征进行了系统的梳理与总结。结果表明:十字铺组为中奥陶世达瑞威尔期晚期(Dw3)的一套以页岩为主的地层,呈条带状近东西向分布于黔北、川东南及滇东北等地区。牯牛潭组是达瑞威尔期(Dw1—Dw3)的一套灰岩相沉积,与下伏和上覆地层的接触关系类型存在四种情况。在其中三种情况下,该组可能与上覆地层之间存在地层缺失。该组底、顶界穿时明显:底界主要介于Dw1晚期至Dw2早期之间,对应牙形石Lenodus antivariabilis带至Lenodus variabilis带;顶界最晚可达Dw3晚期,对应牙形石Pygodus anserinus带,最早仅到Dw1晚期(L.antivariabilis带)。在研究区该组主要分布于川东、重庆大部、黔北、黔东北、鄂西及湘西北地区。在部分地区,牯牛潭组上部可与十字铺组对比。Age and distribution of the Middle Ordovician Shihtzupu（ Shizipu） and Guniutan Formations have been researched based on large amount of conodont data and observations of field trips. It shows that the Late Darriwilian Shihtzupu Formation（ Dw3） is dominated by shale and has a banding distribution along west—east direction including areas of northern Guizhou,southeastern Sichuan and northeastern Yunnan. The Guniutan Formation dominated by limestone could be classified into four types according to the characteristics of underlying and overlying strata. Both the base and tope boundaries of it are apparently diachronous. The age of base is between the late of Dw1 and the early of Dw2 corresponding to conodont Lenodus antivariabilis and Lenodus variabilis biozones. The top is from the late of Dw1 to that of Dw3,the latter corresponds to conodont Pygodus anserinus biozone. This formation mainly exists in eastern Sicuan,most of Chongqing,northern to northeastern Guizhou,western Hubei and northwestern Hunan. The upper part of the Guniutan formation could be correlated with the Shihtzupu Formation in part of these areas.

关 键 词：十字铺组 牯牛潭组 牙形石 达瑞威尔期 上扬子区 

分 类 号：P534.42[天文地球—古生物学与地层学]