福建紫金山矿田悦洋银多金属矿床银的赋存状态和沉淀机制  

Silver occurrence state and deportment mechanism of Yueyang Ag polymetallic deposit in Zijinshan ore field,Fujian Province,China

作　　者：刘兰海 陈静[1,2] 周涛发 孙艺[3] WHITE Noel C LIU LanHai;CHEN Jing;ZHOU TaoFa;SUN Yi;WHITE Noel C(Ore Deposits and Exploration Centre(ODEC),School of Resources and Environmental Engineering,Hefei University of Technology,Hefei 230009,China;Anhui Province Engineering Research Center for Mineral Resources and Mine Environments,Hefei 230009,China;Centre of Excellence in Ore Deposits(CODES),University of Tasmania,Hobart 7001,Australia)

机构地区：[1]合肥工业大学资源与环境工程学院,合肥工业大学矿床成因与勘查技术研究中心(ODEC),合肥230009 [2]安徽省矿产资源与矿山环境工程技术研究中心,合肥230009 [3]Centre of Excellence in Ore Deposits(CODES),University of Tasmania,Hobart 7001

出　　处：《岩石学报》2024年第3期987-1002,共16页Acta Petrologica Sinica

基　　金：国家自然科学基金项目(91962218、42002075)资助.

摘　　要：浅成低温热液矿床是世界上银矿的重要矿床类型,伴生有金铜铅锌等多种金属。银的赋存状态研究可以为矿床资源禀赋、选冶成本以及经济价值的综合评价提供重要的依据。近年来,矿物自动定量分析系统越来越多地应用到贵金属的赋存状态研究中,相比传统方法而言其能提供精确定量的矿物学信息。悦洋银多金属矿床位于福建省紫金山矿田,是典型的浅成低温热液矿床,是研究银赋存状态的理想选区。通过野外地质调查研究发现,矿体主要受控于岩性边界和断裂构造,主要矿石类型为热液角砾岩型和石英脉型。成矿作用可以分为石英-黄铁矿、石英-黄铁矿-黄铜矿、石英-银多金属、石英-碳酸盐等四个阶段,其中银在石英-银多金属阶段沉淀,可以进一步划分为石英伊利石硫化物亚阶段和石英冰长石硫化物亚阶段。本文在野外地质调查的基础上,针对不同的矿石类型使用TIMA(TESCAN Integrated Mineral Analyzer)自动矿物分析系统,结合显微镜下观察、扫描电镜和电子探针分析手段,对银的赋存形式和分布情况进行了定量化研究,根据矿物共生组合对银沉淀机制及成矿过程进行了探讨。研究结果显示,悦洋矿床中的银90%以上以独立矿物的形式存在,主要是硫化银和自然银,且粒径大多在10~50μm之间;少部分银以次显微包裹体形式存在于黄铜矿中,或以显微包裹体和类质同相形式存在于黄铁矿和闪锌矿中。成矿热液中银主要以硫氢络合物形式运移,主成矿期大量的冰长石与银矿物共生表明沸腾作用是主要的沉淀机制。Epithermal deposit is an important type of silver deposit in the world.It is associated with gold,copper,lead,zinc and other metals.The study on the silver deportment of epithermal deposits can provide important information on the fertility of the deposit,the cost of processing and smelting of ore,and the overall evaluation of the economic value of the deposit.In recent years,the automatic mineral quantitative analysis system has been more and more applied to the study of the occurrence state of precious metals,which can provide accurate and quantitative mineralogy information compared with traditional methods.Yueyang Ag polymetallic deposit is an epithermal deposit located in the Zijinshan ore field of Fujian Province,is an ideal constituency to study the state of silver occurrence.Through field geological investigation,it is found that the ore body is mainly controlled by lithologic boundaries and structures,and the main ore types are hydrothermal breccia type and quartz vein type.Mineralization can be divided into four stages:quartz-pyrite stage,quartz-pyrite-chalcopyrite stage,quartz-silver polymetallic stage and quartz-carbonates stage.Silver predominantly precipitates in quartz-silver polymetallic stage,and it can be further divided into quartz-illite-sulfide substage and quartz-adularia-sulfide substage.In recent years,the automatic mineral quantitative analysis system based on scanning electron microscope and X-ray energy spectrometer has been more and more applied to the study of the occurrence state of precious metals,which can provide accurate and quantitative mineralogy information compared with traditional methods.In this study,based on the field mapping,the automatic mineral analysis(TIMA)was used to quantitatively investigate the occurrences and distribution of silver-bearing minerals,and the deportment mechanism and formation of silver was discussed by microscopic observation,scanning electron microscope(SEM)and electron microprobe analysis(EPMA).Based on the results of the TIMA(TESCAN Integrated

关 键 词：银的赋存状态 矿物定量分析 银的沉淀机制 浅成低温热液矿床 紫金山矿田 

分 类 号：P575[天文地球—矿物学] P618.52[天文地球—地质学]