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现代地质 ›› 2012, Vol. 26 ›› Issue (2): 269-276.

• 矿床学 • 上一篇    下一篇

湖北嘉鱼县蛇屋山金矿硅质岩地球化学特征及成矿环境约束

 徐萌萌1, 徐广东2, 孙祥民3, 朱本杰3, 刘蕴光2, 肖凡2, 许荣科4, 徐永利2, 李宝庆2   

  1. 1 中国地质大学  地球科学与资源学院,北京100083;2 中国地质大学 资源学院,湖北 武汉430074;3 湖北省地质矿产勘查开发局 第四地质大队,湖北 咸宁437100;4 中国地质大学 地质调查研究院,湖北 武汉430074
  • 收稿日期:2011-09-20 修回日期:2011-12-15 出版日期:2012-04-20 发布日期:2018-09-19
  • 通讯作者: 许荣科,男,副教授,1968年出生,矿产普查与勘探专业,主要从事矿床学研究。
  • 作者简介:徐萌萌,女,硕士研究生,1987年出生,矿物学、岩石学、矿床学专业,主要从事矿床学研究。Email:xumengmeng123_0@163.com。
  • 基金资助:

    湖北省地质矿产勘查开发局科研项目(鄂地矿科研[2009]3号)“ 嘉鱼蛇屋山金矿原生矿富集规律及找矿预测研究”(Ky2009-3)。

Geochemistry of Cherts from Shewushan Gold Ore Deposit  in Jiayu, Hubei Province and Its Metallogenic Environmental Constraints

 XU  Meng-Meng-1, XU  An-Dong-2, SUN  Xiang-Min-3, SHU  Ben-Jie-3, LIU  Wen-Guang-2, XIAO  Fan-2, HU  Rong-Ke-4, XU  Yong-Li-2, LI  Bao-Qiang-2   

  1. 1 School of Earth Sciences and Resources,China University of Geosciences, Beijing100083,China; 2 Faculty of Earth Resources, China University of Geosciences, Wuhan, Hubei430074, China;3 The Fourth Geological Team of Bureau of Geological Exploration ﹠Development of Hubei Province, Xianning, Hubei437100, China; 4 Institute of Geological Survey, China University of Geosciences, Wuhan, Hubei430074, China
  • Received:2011-09-20 Revised:2011-12-15 Online:2012-04-20 Published:2018-09-19

摘要:

湖北蛇屋山金矿是亚洲最大的红土型金矿,矿区内硅质岩发育,覆于含矿红土层之上,并与硅化灰岩呈渐变过渡。硅质岩主要由微晶和隐晶组成, 其SiO2含量为96.87%~97.90%,w(Si)/w(Al)=92.84~287.66,平均值为173,处于纯硅质岩的范畴。硅质岩样品的w(Al)/w(Al+Fe+Mn)为0.189~0.388,平均值为0.303,具热液成因硅质岩的特征。根据Al、Fe、Mn三角图的投点,认为本研究区硅质岩为热液成因硅质岩。微量元素w(Ni)/w(Co)、w(Fe)/w(Ti)、w(Ti)/w(V)、w(U)/w(Th)也说明了硅质岩具有热水沉积成因。w(Ce)/w(Ce*)为1.05~1.27,平均值为1.12,(La/Ce)N为0.84~1.12,平均值为0.98,微量元素V的含量(3.02~4.26 μg/g)以及常量元素w(MnO)/w(TiO2)(1.0~2.0)都显示此研究区硅质岩具有大陆边缘硅质岩的特征。结合宏观特征,确定硅质岩有可能形成于卡林型金矿去碳酸盐化阶段,属于热液活动的产物。

关键词: 硅质岩, 地球化学, 沉积环境, 蛇屋山金矿, 湖北

Abstract:

The Shewushan gold deposit is the largest lateritetype gold ore deposit in Asia, and authors discover that cherts covered on the top of the red soil  in the gold ore deposit, showing a gradual transition relationship with the silicified limestone. The analysis of cherts approves that the SiO2 content is from 96.87% to 97.90%,and that the Si/Al ratio ranges from 92.84 to 287.66 with average value of 173, therefore, the cherts could be classified as pure cherts. The Al/(Al+Fe+Mn)ratios of chert samples in the research area are between 0.189 and 0.388,and the average value is 0.303, implying that the cherts is of hydrogenous genesis. AlFeMn diagram shows that the cherts is also hydrothermal type,and the ratios of Ni/Co, Fe/Ti, Ti/V and U/Th show that cherts  from Shewushan are hydrothermally sedimentary origin. The ratios of Ce/Ce* and(La/Ce)N is 1.05-1.27 and 0.84-1.12 with average value of 1.12 and 0.98, respectively. The trace element V content is 3.02-4.26 μg/g and the ratio of MnO/TiO2 is 1.0-2.0, which indicated that the radiolarian chert formed in transitional environment of continental margin basin. Combining with the macro characteristics, we regard that cherts probably formed in the Carlin type golds stage of eliminate carbonatization, which are the product of hydrothermal activity.

Key words: geochemistry, depositional setting, Shewushan gold ore deposit, Hubei