西南石油大学学报(自然科学版) ›› 2007, Vol. 29 ›› Issue (5): 45-47,5.DOI: 10.3863/j.issn.1000-2634.2007.05.12

• 地质勘探 • 上一篇    下一篇

歧口凹陷沙一段颗石灰岩的发现及其环境意义

牟晓慧1 董兆雄1,2 张建3 李会慎3 李宏军3

  

  1. 1. 西南石油大学资源与环境学院,四川 成都 610500;2.“油气藏地质及开发工程”国家重点实验室·西南石油大学;3. 大港油田分公司勘探开发研究院
  • 收稿日期:2007-05-21 修回日期:1900-01-01 出版日期:2007-10-20 发布日期:2007-10-20
  • 通讯作者: 牟晓慧

THE FINDING OF COCCOLITH LIMESTONE AND ITS ENVIRONMENT SIGNIFICANCE IN QIKOU DEPRESSION IN SHAHEJIE ⅠMEMBER

MU Xiao-hui1 DONG Zhao-xiong1,2 ZHANG Jian3 et al.   

  1. Resources and Environment Institute,Southwest Petroleum Univesity,Chengdu Sichuan 610050,China
  • Received:2007-05-21 Revised:1900-01-01 Online:2007-10-20 Published:2007-10-20
  • Contact: MU Xiao-hui

摘要: 歧口凹陷沙河街组一段广泛发育“纹层状钙质泥岩”、“油页岩”,然而,通过光学显微镜、扫描电镜观察以及全岩X射线衍射分析,显示这些“纹层状钙质泥岩”、“油页岩”相当部分是由泥岩和颗石灰岩呈纹层状互层构成的。颗石灰岩的地球化学分析、矿物学研究结果表明其与海水有关,进一步比较现代黑海颗石藻发育环境及纹层状的颗石藻沉积物特征,发现歧口凹陷乃至渤海湾盆地沙一段广泛发育的颗石灰岩与黑海颗石藻沉积物产状极为类似。这说明歧口凹陷颗石灰岩是在渤海湾盆地与外海沟通期间,由外海进入渤海湾湖盆的颗石藻勃发、沉积的结果。

关键词: 颗石灰岩, 沙河街组一段, 湖-海沟通, 歧口凹陷, 古近纪

Abstract: In Shahejie ⅠMember in Qikou Depression, the massive “alcareous laminated mudstone”or “Bituminous rock”are discovered. However, by means of the optical microscope, the scanning electron microscope observation as well as the entire cock Xray diffraction analysis, it is identified most part of these “alcareous laminated mudstone”, “Bituminous rock”are composed by mudstone and coccolith limestone. The limestone geochemistry analysis, the mineralogy findings indicated that the forming of coccolith limestone were related with sea water, further compared with coccolith growth environment and the characteristic of its deposit in modern Black Sea, it is discovered the coccolith limestone of Shahejie ⅠMember in Qikou depression and even Bohai basin is similar to the coccolith limestone in the Black Sea. This indicate that at the communication period between Bohai Bay and sea, coccolith limestone in Qikou Depression is the result of blooms and deposition of coccolith when it entered the Bohai Basin from the open sea.

Key words: coccolith limestone, Shahejie ⅠMember, connection the sea and lake, Qikou Depression, Paleogene

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