地学前缘 ›› 2010, Vol. 17 ›› Issue (1): 153-163.

• 论文 • 上一篇    下一篇

岩浆通道系统与岩浆硫化物成矿研究新进展

  

  1. 1中国科学院 地球化学研究所 矿床地球化学国家重点实验室, 贵州 贵阳 550002
    2中国科学院 研究生院, 北京 100049
  • 出版日期:2010-01-28 发布日期:2010-01-20
  • 作者简介:宋谢炎(1962—),男,研究员,博士生导师,岩石与矿床地球化学专业。Email: songxieyan@vip.gyig.ac.cn
  • 基金资助:

    国家重点基础研究发展计划“973”项目(2006CB403200,2007CB411408);国家自然科学基金重点项目(40730420,40973038);中国科学院“百人计划”项目

New insights on the formation of magmatic sulfide deposits in magma conduit system.

SONG  Xie-Tan, XIAO  Jia-Fei, SHU  Dan, SHU  Wei-Guang, CHEN  Li-Meng   

  1. 1State Key Laboratory of Ore Deposit Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences,  Guiyang 550002, China
    2Graduate University of Chinese Academy of Sciences, Beijing 100049, China
  • Online:2010-01-28 Published:2010-01-20

摘要:

大型超大型岩浆硫化物矿床的形成需要满足3个基本条件:(1)大量幔源岩浆参与成矿;(2)岩浆演化导致硫化物熔离;(3)硫化物在有限空间聚集。然而,除Sudbury矿床外,全球与镁铁质岩浆有关的超大型铜镍硫化物矿床都发现于小的镁铁超镁铁岩体中。近10年来的研究表明这些含矿岩体实际上都是岩浆通道系统的一部分,中国金川、杨柳坪、喀拉通克、红旗岭等大型和超大型NiCu(PGE)硫化物矿床都形成于岩浆通道系统中,正是岩浆通道这样特殊的开放系统为大规模岩浆硫化物矿床提供了成矿条件。总结国内外最新研究结果,可以发现与成矿有关的岩浆通道系统都分布在深大断裂附近,大规模的幔源岩浆补充与地幔柱、大陆裂谷、碰撞造山后伸展等地质事件有密切的关系。尽管研究证明硫化物熔离都与地壳物质的混染有关,但矿石各种元素的品位却受母岩浆性质、硫化物熔离强度、与新注入镁铁质岩浆反应、以及硫化物本身结晶分异等多重因素的影响;含矿岩体和硫化物矿体的形态和大小都强烈地受围岩地质特征的控制。进一步明确这类矿床的地质特征、形成机制、成矿背景和成矿标志,对未来的研究和找矿工作都是非常必要的。

关键词: 岩浆铜镍硫化物矿床, 岩浆通道系统, 硫化物熔离, 构造伸展

Abstract:

 The three most important elementary factors for the formation of largesuper large magmatic sulfide deposits are that (1) large amount of mantlederived magmas participate in the formation of the deposits, that (2) magmatic evolution results in sulfide immiscibility, and that (3) the sulfides concentrate in a limited space. However, the superlarge magmatic NiCu sulfide deposits over the world have been found in small maficultramafic intrusions, except for the Sudbury deposit. The studies in the past 10 years indicated that the intrusions hosting superlarge magmatic sulfide deposit occur in magma conduit systems. For example, many of the large and superlarge magmatic sulfide deposits in China, including Jinchuan, Yangliuping, Kalatongke, and Hongqiling, occur in the magma conduit systems. The magma conduit system as an open system provides a perfect environment for extensive concentration of immiscible sulfide melts. The recent studies indicated that the magmatic sulfide deposits related magma conduit systems in the world occur along deep regional faults. Origin of the large amount of mantlederived magma is closely associated with mantle plume, continental rift, or post orogenic extension. Although it has been confirmed that sulfide immiscibility results from crustal contamination, the grades of the sulfide ores are also related to natures of the parental magmas, ratios between silicate magma and immiscible sulfide melt, reaction between the sulfide melts and the new injected silicate magmas, and fractionation of the sulfide melt. The field relationships of the sulfide containing intrusion and sulfide ore body are controlled by geological features of the hosting wallrocks. In this paper, we attempt to demonstrate the general features, formation mechanism and geological background, and significance of the magmatic sulfide deposits occurring in magmatic conduit system, which are very important for the further researches and exploration of this type of magmatic sulfide deposits.

Key words: magmatic NiCu sulfide deposit, magma conduit system, sulfide immiscibility, tectonic extension

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