滇西北衙铁金多金属矿床的成矿作用过程——来自菱铁矿元素地球化学特征的约束
DOI:
作者:
作者单位:

作者简介:

通讯作者:

中图分类号:

P578.6+1;P618.3

基金项目:

中国地质调查局工作项目(DD20160020,DD20190053)


Ore-forming process of the Beiya Fe-Au-polymetallic deposit in western Yunnan: Constraints from geochemical characteristics of siderite
Author:
Affiliation:

Fund Project:

  • 摘要
  • |
  • 图/表
  • |
  • 访问统计
  • |
  • 参考文献
  • |
  • 相似文献
  • |
  • 引证文献
  • |
  • 资源附件
  • |
  • 文章评论
    摘要:

    北衙铁金多金属矿床位于西南"三江"新生代富碱斑岩成矿带内,发育接触交代蚀变及与热液有关的脉状(囊状)、条带状(似层状)矿化,构成一个巨型岩浆热液成矿系统。岩体蚀变围岩或破碎裂隙带内常见大量与方铅矿、黄铁矿、黄铜矿等共(伴)生的脉(囊)状菱铁矿化,以菱铁矿为代表的Ⅱ阶段成矿明显晚于Ⅰ阶段磁铁矿成矿,是示踪成矿流体过程的理想矿物。矿相学观测表明,菱铁矿可分为穆磁铁矿型(Sd1型)、(含)黄铁黄铜矿-穆磁铁矿型(Sd2型)和方铅矿型(Sd3型)3种类型。通过电子探针(EMPA)和等离子质谱(ICP-MS)分析,认为从Ⅰ阶段向Ⅱ阶段转换过程中,成矿流体由中性或弱碱性、高温、氧化性逐渐向弱酸性、较低温、还原性环境过渡,并以Sd1、Sd2型菱铁矿的生成为标志,分别伴生大量的穆磁铁矿及黄铁矿、黄铜矿等,金与以黄铁矿为主的载金矿物同步沉淀;伴随温度的降低,成矿流体完全转变为酸性、还原性,此时大量Sd3型菱铁矿与方铅矿沉淀析出。3类菱铁矿与Ⅰ阶段磁铁矿的成矿流体具有一致的来源,是在不同空间部位逐渐沉淀的产物。

    Abstract:

    The Beiya Fe-Au-polymetallic deposit lies in the alkali-rich porphyry polymetallic metallogenic belt of northwest Yunnan Province. There exist the contact metasomatic-hydrothermal alteration, ore types of metasomatite and filling veins in the host rocks, which have formed a mineralization system of porphyry. Within cracks and fracture zones of the host rocks or Fe orebody, there are lots of associated sulfide minerals such as siderites, gelenites, pyrites and chalcopyrites. The siderites at Ⅱ stage is obviously later than magnetites at Ⅰ stage, and they are the ideal minerals. A study of chalcography shows that the siderites can be classified into three types, i.e., magnetite-siderite (Sd1), pyrite-chalcopyrite-magnetite-siderite (Sd2) and gelenite-siderite (Sd3). EPMA and ICP-MS analysis of siderites show that, during the transition from Ⅰ-stage to Ⅱ-stage, the intermediate or weakly alkaline, high temperature and oxidation mineralization was converted to weak acid, low temperature and weak reduction, as marked by the generation of mushketovite. Meanwhile, there were a lot of polymetallic sulfides, with pyrites as the main Au-bearing minerals, and Au deposits were simultaneously developed. With the further decreasing temperature, the ore-forming process completely changed into acidity and strong reduction, with the deposition of gelenites and siderites. So all types of siderites and earlier magnetites had the same trace ore-metal source and ore-forming process, resulting from the evolution of ore-forming fluids at different stages and periods, and mineralization occurred at proper location with different ore-forming processes and decreasing temperature.

    参考文献
    相似文献
    引证文献
引用本文

牛浩斌,丁俊,李俊,宁括步,王鹏,任飞,孙建成,2019,滇西北衙铁金多金属矿床的成矿作用过程——来自菱铁矿元素地球化学特征的约束[J].岩石矿物学杂志,38(4):553~569. NIU Hao-bin, DING Jun, LI Jun, NING Kuo-bu, WANG Peng, REN Fei, SUN Jian-cheng,2019,Ore-forming process of the Beiya Fe-Au-polymetallic deposit in western Yunnan: Constraints from geochemical characteristics of siderite[J]. Acta Petrologica et Mineralogica,38(4):553~569.

复制
分享
文章指标
  • 点击次数:
  • 下载次数:
  • HTML阅读次数:
  • 引用次数:
历史
  • 收稿日期:2018-03-28
  • 最后修改日期:
  • 录用日期:
  • 在线发布日期: 2019-07-15
  • 出版日期: