山东乳山金矿中金-银碲化物的矿物学特征与沉淀机理  

Au-Ag TELLURIDE MINERALS AND THEIR PRECIPITATION MECHANISM IN THE RUSHAN GOLD DEPOSIT, SHANDONG

作　　者：胡文瑄[1] 孙国曦[1] 张文兰[1] 王昭坤 

机构地区：[1]南京大学地球科学系内生金属矿床成矿机制国家重点实验室,江苏南京210093 [2]山东黄金集团有限公司山东省黄金工业局,山东济南270000

出　　处：《矿物学报》2005年第2期177-182,共6页Acta Mineralogica Sinica

基　　金：国家自然基金项目(批准号:49973001)

摘　　要：通过显微鉴定和应用电子探针微束分析,查明乳山金矿中碲化物主要为碲银矿和碲金银矿,少量碲铅矿和碲铋矿,它们呈密切共生的集合体或联生体产出在黄铁矿等硫化物及石英等脉石矿物粒间或裂缝中。碲银矿和碲金银矿中Au含量变化较大,w(Au)为痕量至26.1%,与银呈负相关,与铋为正相关,可能是以类质同象形式替代Ag进入到碲银矿中;碲铅矿中未检测到金。金在金-银碲化物中的含量随温度降低而升高,相关矿物的形成顺序为碲银矿—碲金银矿—(碲金矿)。将金银碲化物成分投到Au-Ag-Te三元成分-共生图解上发现,它们都不是标准成分的端元矿物,推测这些碲化物(尤其是金银碲化物)是在非平衡状态下快速沉淀形成的,可能与含矿流体的间歇性沸腾作用有关。Based on microscopic observation and electron probe micro-analysis （EPMA）, teUuride minerals in the Rushan gold deposit, Shandong province, were studied and their compositions were measured. The major telluride minerals are hessite and petzite, with some alaite and teUurobismuthite intergrowthed, occurring as a closely paragenetic group（aggregate） in inter-crystal poroses or fractures of sulfides and gangue minerals. The contents of gold in hessite and petzite vary largely from trace to 26. lwt%, which is believed to occur as an isomorphic form of Ag in hessite. Gold is negatively correlated with silver. In addition, Au seems to have a positive correlation with bismuth, but it is bellow the detection limit in ahaite. Therefore, Au occurs mainly in hessite and petzite. In combination with recent achievements in literature, it is suggested that gold contents in the Au-Ag teUuride tend to increase with decreasing temperature, and the precipitation sequence should be hessite-petzite （calaverite）. By putting the measured data into the diagram of the Au-Ag-Te ternarysystem, it can be seen that the compositions of the telluride minerals do not fit those of the end members in the diagram.It is believed that the telluride minerals were precipitated in an unequilibrittm system, which could be related to an unstable ore-forming system because of boiling processes during the formation of the deposit.

关 键 词：金矿 碲化物 共生关系 沉淀机制 

分 类 号：P571[天文地球—矿物学] P618.51[天文地球—地质学]