会泽铅锌矿床环带状闪锌矿中主微量元素分布特征及其意义  

The distribution signatures of major and trace elements in zoned sphalerite from lead-zinc deposits:A case study from the Huize deposit

作　　者：李云刚 朱传威[2] LI Yun-Gang;ZHU Chuan-Wei(No.3 Geology Mineral Resources Exploration and Development Co.LTD of Inner Mongolia,Huhehaote 010050,China;State Key Laboratory of Ore Deposit Geochemistry,Institute of Geochemistry,Chinese Academy of Sciences,Guiyang 550081,China)

机构地区：[1]内蒙古第三地质矿产勘查开发有限责任公司,内蒙古呼和浩特010010 [2]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550081

出　　处：《矿物学报》2020年第6期765-771,共7页Acta Mineralogica Sinica

基　　金：国家自然科学基金项目(批准号:41773012);贵州省基金项目(批准号:[2016]1159和[2019]1459)。

摘　　要：以会泽矿床中环带状闪锌矿为对象,通过EPMA和LA-ICP-MS等手段,研究环带状闪锌矿中主微量元素在单矿物尺度的空间和时间变化规律。结果表明,早期(深色)闪锌矿相对贫Cd富Fe,而晚期(浅色)闪锌矿相对富Cd贫Fe,流体中高Fe含量会抑制Cd进入闪锌矿晶格。同时,闪锌矿中Cd^2+主要以直接替代Zn^2+的形式进入闪锌矿中,而不需要与Fe^2+耦合替代进入闪锌矿晶格。Ge和Cu具有极强的相关性,Ge^4+需要和Cu^+协同进入闪锌矿中,其替代方式可能为3Zn^2+Ge^4■2Cu^+。In和Ga具有极强的相关性,暗示In和Ga协同进入闪锌矿中,如3Zn^2+Ga^3■In^3+。闪锌矿中In和Ga含量随颜色变浅而增加,说明In和Ga易富集于晚期闪锌矿中。Tl、Se和Mn在闪锌矿颜色的突变线位置含量会有所升高,暗示这3个元素对成矿流体成分变化敏感。In this study,EPMA and LA-ICP-MS techniques were employed to investigate the temporal and spatial variations of major and trace elements in a zoned sphalerite from the Huize deposit.The results show that early stage sphalerite(dark color)is Cd-rich and Fe-poor sphalerite;by contrast,late stage sphalerite(light color)is Cd-poor and Fe-rich sphalerite.Cd in sphalerite mainly enters into lattice of sphalerite in the form of direct substitution of Zn,and does not require synergistic Fe to incorporate into sphalerite lattice.Ge and Cu show very similar distribution signatures in zoned sphalerite,suggesting that Ge and Cu substitute Zn into sphalerite as(3Zn^2+Ge^4+■2Cu^+).In and Ga have similar distribution characteristics in the mapping figures,suggesting that In and Ga synergistically incorporate into sphalerite,such as 3Zn^2+Ga3^+■In^3+.Meanwhile,In and Ga are enriched in dark sphalerite,suggesting that they are easier to be incorporated into late stage sphalerite.Meanwhile,the contents of Tl,Se and Mn are sharply increased at the boundaries between different colored sphalerite,suggesting that these elements maybe sensitive to the variations of chemical compositions of ore-forming fluid.

关 键 词：闪锌矿 稀散元素 LA-ICP-MS mapping 赋存状态 会泽铅锌矿床 

分 类 号：P595[天文地球—地球化学]