石油学报 ›› 2019, Vol. 40 ›› Issue (5): 577-586.DOI: 10.7623/syxb201905007

• 地质勘探 • 上一篇    下一篇

重庆南川地区中奥陶统—上奥陶统牙形石序列及地质意义

马雪莹1, 樊茹1, 卢远征1, 罗忠1, 邓胜徽1, 张放2   

  1. 1. 中国石油勘探开发研究院 提高采收率国家重点实验室 中国石油天然气集团公司油气储层重点实验室 北京 100083;
    2. 中国石油华北油田公司勘探开发研究院 河北任丘 062550
  • 收稿日期:2018-11-27 修回日期:2019-03-18 出版日期:2019-05-25 发布日期:2019-06-03
  • 通讯作者: 邓胜徽,男,1963年07月生,1985年获合肥工业大学矿产普查与勘探专业学士学位,1991获中国地质大学(北京)地层古生物专业博士学位,现为中国石油勘探开发研究院教授级高级工程师,主要从事地层与古生物研究。Email:dsh63@petrochina.com.cn
  • 作者简介:马雪莹,女,1987年12月生,2011年获中国石油大学(北京)地质工程专业学士学位,2013年获澳大利亚阿德雷德大学石油工程专业硕士学位,现为中国石油勘探开发研究院博士研究生,主要从事地层与古生物研究。Email:752032397@qq.com
  • 基金资助:

    国家科技重大专项(2017ZX05001)、中国石油天然气股份有限公司科技重大专项(2016A-0206)和国家自然科学基金项目(No.41702031)资助。

Middle-Upper Ordovician conodont sequence and its geological significance in Nanchuan area, Chongqing

Ma Xueying1, Fan Ru1, Lu Yuanzheng1, Luo Zhong1, Deng Shenghui1, Zhang Fang2   

  1. 1. PetroChina Research Institute of Petroleum Exploration and Development;State Key Laboratory of Enhanced Oil Recovery;CNPC Key Laboratory of Oil and Gas Reservoir, Beijing 100083, China;
    2. Research Institute of Exploration and Development, PetroChina Huabei Oildfield Company, Hebei Renqiu 062550, China
  • Received:2018-11-27 Revised:2019-03-18 Online:2019-05-25 Published:2019-06-03

摘要:

通过对重庆南川地区三泉镇中奥陶统-上奥陶统的露头剖面进行连续的牙形石采样分析,确定了29属55种牙形石,建立了8个牙形石带,自下而上分别为Baltoniodus norrlandicus带、Lenodus antivariabilis带、Lenodus variabilis带、Pygodus serra带、Yangtzeplacognathus jianyeensis带、Baltoniodus variabilis带、Hamarodus brevirameus带和Protopanderodus insculptus带,其发育时代为中奥陶世达瑞威尔期-晚奥陶世凯迪期。其中,可能缺失2期牙形石带及相应的地层,包括牯牛潭组顶部缺失与湖北宜昌地区黄花场剖面相对应的Yangtzeplacognathus protoramosus带,大田坝组与宝塔组之间缺失与黄花场剖面大致相当的Baltoniodus alobatus带。从中扬子的湖北宜昌地区向西至重庆石柱地区,再到上扬子的重庆南川-贵州习水地区,中奥陶统-上奥陶统由发育完整转变为在中奥陶统达瑞威尔阶中-上部缺失1期牙形石带及相应地层,在达瑞尔威尔阶的中-上部和桑比阶内部缺失2期牙形石带及相应地层。地层特征表明,中奥陶世-晚奥陶世上扬子地区曾存在古陆,而中扬子地区则一直保持了海洋的古地理格局。

关键词: 中奥陶统&mdash, 上奥陶统, 牙形石, 上扬子地区, 南川地区, 古地理

Abstract:

This study collects and analyzes the conodont samples from the Middle-Upper Ordovician in Sanquan town, Nanchuan area of Chongqing, identifies 29 genera and 55 species and establishes 8 conodont biozones, i.e., Baltoniodus norrlandicus, Lenodus antivariabilis, Lenodus variabilis, Pygodus serra, Yangtzeplacognathus jianyeensis, Baltoniodus variabilis, Hamarodus brevirameus and Protopanderodus insculptus from bottom to top. Their development time was from Middle Ordovician Darriwilian Stage to Late Ordovician Katian Stage. Among them, two conodont biozones and corresponding formations may be absent, including the biozone in the top of Guniutan Formation corresponding to the Yangtzeplacognathus protoramosus biozone in the Huanghuachang profile of Yichang area, Hubei province and the biozone between Datianba Formation and Baota Formation equal to the Baltoniodus alobatus biozone in the Huanghuachang profile. From Yichang area of Hubei in the Middle Yangtze region westwards Shizhu area of Chongqing to Nanchuan area of Chongqing in the Upper Yangtze till Xishui of Guizhou, the Middle-Upper Ordovician was transformed from integrity into absence of one conodont biozone and corresponding strata in the middle-upper Middle Ordovician Darriwilian Stage, and two conodont biozones and corresponding strata in the middle-upper Darriwilian Stage and the inner Sandbian Stage. The stratigraphic characteristics indicate that ancient continent existed in the Upper Yangtze area, while the palaeo-ocean still remained in the Middle Yangtze area during Middle-Late Ordovician.

Key words: Middle-Upper Ordovician, conodont, the Upper Yangtze area, Nanchuan area, paleogeography

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