东珺矿床是近年在内蒙古额尔古纳地区陆相火山岩系内新发现的一处脉状Pb-Zn-Ag矿床,其以富含多量Ag及微量Au为特征.在野外考察的基础上,本文以电子探针、能谱-扫描电镜及多项光谱分析等方法查明了其矿石中Au、Ag的赋存状态及矿物组成,其主要矿物包括辉银矿、火硫锑银矿、黝锑银矿、深红银矿、硫锑铜银矿及脆银矿.除此,还发现了一些罕见的矿物,如碲铋矿、硫锑铜矿的锌变种、针硫铋铅矿、库辉铋铜铅矿以及某些未知的Pb-Bi相金属矿物.为了估算本矿床的成矿温度,着重对矿床中的银锑黝铜矿系列的组成做了分析,并将其Ag/(Ag+ Cu)及Zn/(Zn+ Fe)数值投至Sack等温曲线图上,由其结果可判断出本矿床应属于浅成低温成因,而深部矿体中碲铋矿及无Ag硫盐的出现亦可视为一重要旁证.东珺矿床丰富的银矿物及其粗大粒度对于矿山工艺流程选定以及开发利用将会大有裨益,而本矿床Au含量过低,仅具有地球化学的理论意义.%Dongjun Pb-Zn-Ag deposit discovered in recent few years is located in Erguna district of Inner Mongolia,China.On the basis of open-air investigation,the mineralogical composition in the deposit and the contents of Ag,Au were determined by using EMP,SEM attached EDS,Atomic Absorption Spectra,ICPMS,etc.These minerals mainly include argentile,pyrostilpnite,freibergite,pyrargyrite,polybasite and stephanite.Moreover,some rare minerals such as tellurobismuthite,skinnerite,aikinite,krupkaite and certain unnamed Pb-Bi phase mineral were also discovered in rock.In order to estimate temperature of mineralize of the deposit,the chemical composition of tetrahedrite-Ag series in ore was analyzed.According to the value of Ag/(Ag + Cu) and Zn/(Zn + Fe),plotted on Sack's isothermal curves.It is considered that Dongjun deposit should be an epithermal genesis,many non-silver sulfosalt and tellurobismuthite arose in deep orebody may be an important collateral evidence.This paper emphasized that the silver sulfosalt mineral with large grain in Dongjun deposit is beneficial.It is favorable for technological process and utilization of mine.However,the gold is only meaningful for geochemistry due to low production-grade.
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