投稿时间：2014-08-02
修订日期：2014-10-13
网络发布日期：2014-12-30
中文摘要:近年来,金属硫化物微量元素研究取得了重大进展,但主要局限于少数常见的硫化物,如黄铁矿。辉钼矿作为内生金属矿床最常见的金属硫化物之一,目前对其微量元素的研究成果还很少,对微量元素的赋存状态及其揭示的成因意义还不明。文章尝试性地对中国57个内生独立钼矿床或共伴生钼矿床中的辉钼矿进行了ICP-MS微量元素分析。结合元素的地球化学性质及前人的研究成果,认为除Re、Os等少数元素可成类质同象存在于辉钼矿中以外,推测大部分微量元素可能以固溶体出溶、机械混入物或流体包裹体等形式存在于辉钼矿中。各矿床中辉钼矿微量元素相对于中国陆壳富集Cu、Zn、Pb、W等常见的成矿元素,暗示不同地质环境下不同时代和矿床类型的成钼流体搬运的成矿元素具有一致性和普遍性,这是造成钼多金属矿床金属元素矿化分带的基础。辉钼矿的主要微量元素呈对数正相关,受矿床类型和产出环境影响不大;辉钼矿Co/Ni比值多数<1,集中于0.01~0.57,不同矿床类型的Co/Ni比值具有一定规律性:当w(Co)<30 μg/g时,斑岩型和矽卡岩型矿床中辉钼矿的Ni含量比较稳定;当w(Co)>30 μg/g时,Ni含量比较高;石英脉型矿床的Co/Ni比值变化较大,且小于斑岩型矿床的Co/Ni比值。在内生金属矿床中,辉钼矿主要形成于还原性环境中,但石英脉型矿床的形成条件与斑岩型矿床相比,其氧化性明显增强。根据分析结果和前人研究成果,推测成钼流体应为富CO2和Cl-(个别还富含F-)以及部分还原性气体成分(H2、CO、CH4等)的成矿流体。
Abstract:A significant progress has been made in the study of trace elements of metal sulfides; nevertheless, the study has been confined to a few common sulfides, such as pyrite. The trace elements in molybdenite, which is one of the most common metal sulfides of endogenous deposits, have been very insufficiently studied. The modes of occurrence of trace elements in molybdenite and their genetic information remain unclear. In this paper, the authors chose molybdenites from 57 molybdenum deposits for ICP-MS trace elements dating. In combination of geochemical properties of elements and the results of other researchers, the authors hold that most of the trace elements may exist as solid solution exsolution, mechanic admixture or fluid inclusions in molybdenite except for a few elements such as Re and Os which exist in the form of isomorph. Relative to some common ore-forming elements such as Cu, Zn, Pb and W that are commonly seen in China's continent crust, the enrichment of trace elements in molybdenites of various deposits implies a consistency and universality of trace elements carried by ore-forming fluids from deposits with different ages and different geological environments. This may constitute the basis of metallogenic zones with different ore-forming elements. Main trace elements from molybdenites show logarithmic positive correlation, and are less affected by deposit types and environments. Co/Ni ratios of most molybdenites are less than 1, being mostly concentrated between 0.01 and 0.57. Co/Ni ratios of different deposit types exhibit some certain regularities: When Co content <30 μg/g, Ni content is stable in molybdenites from porphyry type and skarn type deposits; when Co content >30 μg/g, the range of Ni content is large; Co/Ni ratios of quartz vein type deposits change considerably and are lower than Co/Ni ratios of porphyry deposits. Molybdenites commonly were formed in a reduction environment with relatively high temperature, but quartz vein-type deposits were formed in more oxidative environment than porphyry deposits. Based on analytical results and the experimental results of melt/fluid, the authors consider that molybdenum-forming fluid is usually rich in CO2, Cl- (may be also rich in F-) and some reducing gases (H2,CO,CH4), indicating a reducing environment.
keywords:geochemistry molybdenite modes of occurrence of elements property of ore-forming fluids metallogenic prediction
文章编号：
中图分类号：P618.65
文献标志码：
基金项目:本文得到国家自然科学基金项目(编号: 41402069)、中央级公益性科研院所基本科研业务费专项资金项目(编号: K1305)、中国地质大调查项目中国矿产地质与区域成矿规律综合研究(中国矿产地质志)项目(编号: 12120114039701; 12120114039601)和全国矿产资源潜力评价项目(编号:1212010633901)联合资助
引用文本：
黄凡,王登红,陈毓川,王成辉,唐菊兴,陈郑辉,王立强,刘善宝,李建康,张长青,应立娟,王永磊,李立兴,李超.2014.中国内生钼矿床辉钼矿的微量元素特征研究[J].矿床地质,33(6):1193~1212HUANG Fan,WANG DengHong,CHEN YuChuan,WANG ChengHui,TANG JuXing,CHEN ZhengHui,WANG LiQiang,LIU ShanBao,LI JianKang,ZHANG ChangQing,YING LiJuan,WANG YongLei,LI LiXing,LI Chao.2014.Trace elements characteristics of molybdenites from endogenous molybdenum deposits in China[J].Mineral Deposits33(6):1193~1212
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