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现代地质 ›› 2010, Vol. 24 ›› Issue (3): 545-551.

• 天然气水合物专辑:地球化学 • 上一篇    下一篇

意大利亚平宁地区第三纪中新世“Calcari a Lucina”冷泉碳酸盐岩中结晶扇的沉积岩石学及地球化学特征

黄华谷1,2,邸鹏飞1,2,陈莹莹3,冯东1,陈多福1   

  1. 1中国科学院 广州地球化学研究所 边缘海地质重点实验室,广东 广州510640;
    2中国科学院 研究生院,北京100049;3成都理工大学 材料与化学化工学院,四川 成都610059
  • 出版日期:2010-06-21 发布日期:2010-08-17
  • 通讯作者: 陈多福,男,研究员,博士生导师,1962年出生,地球化学专业,主要从事冷泉碳酸盐岩及天然气水合物研究。
  • 作者简介:黄华谷,男,博士研究生,1981年出生,地球化学专业,主要从事冷泉碳酸盐岩及天然气水合物研究。 Email:huanghg@gig.ac.cn。
  • 基金资助:

    国家自然科学基金项目(40872079,40725011);中国科学院知识创新工程前沿领域项目(GIGCX-04-03)。

Sedimentary and Geochemical Characteristics of Crystal Fan in the “Calcari a Lucina” Cold Seep Carbonate of Miocene in the Northern Apennines, Italy

 HUANG  Hua-Gu1,2, DI  peng-Fei1,2, CHEN  Ying-Ying3, FENG  Dong1, CHEN DUO-Fu1   

  1. 1.Key Laboratory of Marginal Sea Geology, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou,
    Guangdong510640, China;   2.Graduate University of Chinese Academy of Sciences, Beijing100049, China;
    3.College of Materials and Chemical Engineering, Chengdu University of Technology, Chengdu,Sichuan610059, China
  • Online:2010-06-21 Published:2010-08-17

摘要:

结晶扇是冷泉碳酸盐岩的一种标志性沉积构造,主要由文石或重晶石等矿物呈放射状聚集形成。意大利亚平宁地区的第三纪中新统广泛发育冷泉碳酸盐岩,其中“Calcari a Lucina”冷泉碳酸盐岩中发育有典型的结晶扇。结晶扇主要由放射状文石聚集形成,含少量的方解石,具有明显的生长纹层。文石纹层的δ13CPDB为-37.9‰~-53.5‰,δ18OPDB为+2.4‰~+6.0‰,相邻文石纹层之间的δ13CPDB和δ18OPDB值差别明显,可能是与碳和氧的来源及流体渗漏速度有关。全岩稀土元素总量很低,w(REE)为0.23×10-6,页岩标准化模式具有明显的Ce负异常,显示结晶扇形成于氧化环境。

关键词: 结晶扇, 冷泉碳酸盐岩, 沉积岩石学, 地球化学, 氧化环境

Abstract:

Crystal fan is a marked structure of cold seep carbonates, which consists of radial mineral aggregations, e.g., aragonite, barite. Numerous cold seep carbonates developed in the Miocene strata of the northern Apennines in Italy, and there were typical crystal fans in the “Calcari a Lucina” seep carbonate. These crystal fans consist of radial aragonite aggregations with minor calcite and clearly growth lamina. The δ13CPDB values of aragonite lamina of crystal fan are from -37.9‰ to -53.5‰, and the δ18OPDB values are from +2.4‰ to+6.0‰. The δ13CPDB and δ18OPDB values of the adjacent aragonite lamina are significant different, and it might be resulted from the sources of carbon and oxygen and the variation of seep flux. The content of rare earth elements (REE) of crystal fan carbonate is very low (0.23×10-6), and shalenormalized REE patterns show significantly negative Ce anomaly, indicating that crystal fans were deposited in oxidation environment.

Key words: crystal fan, cold seep carbonate, sedimentary petrology, geochemistry, oxidation environment

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