福建上蔡硫－多金属矿区前峰西矿段银的矿床地球化学特征及赋存状态研究

福建上蔡硫－多金属矿区前峰西矿段矿床中银的地球化学背景值普遍偏高，局部富集，从矿石矿相鉴定，扫描电镜分析中得知银是以独立矿物年银矿形式赋存于方铅矿中的．首先由各种藻类生物从海水中摄取Ｓ，Ｆｅ，Ｃｕ，Ｐｂ，Ｚｎ，Ａｇ，Ｔｅ等元素的离子，于成岩成矿阶段形成多种金属矿物。由于Ａｇ，Ｔｅ，Ｐｂ地球化学性质、晶体化学性质相近，Ｔｅ，Ａｇ以类质同象状态进入方铅矿。区域变质－矽卡岩化过程中Ａｇ，Ｔｅ在方铅矿中，也随之结合成Ａｇ２Ｔｅ（碲银矿）熔离出来成为方铅矿的不混熔包体或次生包体。

GEOCHEMICAL CHARACTERS AND OCCURRENCES OF THE SILVER MINERALS FROM QIANFENG MINING SECTION OF THE SHANGCAI POLYMETALLIC PYRITE DEPOSIT,FUJIAN

Abstract The silver minerals from the Qianfeng mining section of the Shancai polymetallic pyrite deposit are found to be commoly abnormally high in geochemical bsckground value of silver so that locally they come to a enrichment degree.Mineragraphic and Sem researches on the ores reveal that silver occurs as independent mineral of hessite in galena. This sceneis recorded by uptaking of S, Fe, Cu, Ph,Zn,Ag and Te by Various algse from sea waters and then transformation st these elements into corresponding metallic minerals in responde to metallogenic and diagenetic reworkings. Similarities of Ag, Te and ph in geochemical and srystullochemical oharacters enabled Te and Ag to isomorphically enter the lattices of galena. Afterwards,regional metumorphism and sturnization caused the two elements to combine onto hessite(Ag2Te)which later liquated out of the galena as its unmiaingor secondary inclusion.