雄村斑岩型铜(金)矿床成矿元素原子比值分析

摘要

通过对西藏雄村斑岩铜(金)矿床成矿元素含量的分析,结果表明Au的含量相对较高,铜矿石中Cu、Au原子比值低于25 000,Au、Mo原子比值高于30,表明其为富金斑岩铜矿床.雄村斑岩铜(金)矿床Cu与Au、Ag的关系比较密切,Au与Mo之间则基本没有关系.矿体主要分布在强烈的绢云母和硅化蚀变带中,Au、Ag主要赋存于黄铜矿中.雄村斑岩型铜(金)矿床成矿深度较浅,而富金斑岩矿床的一般成矿深度为0.4～1.5 km,雄村铜(金)矿床中Mo主要赋存于辉钼矿中,Mo元素多集中在矿体的边缘,含量较低,仅为驱龙斑岩铜矿的1/10.雄村斑岩型铜(金)矿床的形成环境为岛弧或似岛弧环境.%The analysis on the ore-forming contents of Xiongcun porphyry copper deposits in Tibet showed that Gold content are relatively high. The copper ores exhibit Cu/Au atomic ratios much smaller than 25 000, Au/Mo atomic ratios greater than 30,which signify them as gold-rich porphyry copper deposits. There is a close correlation between Au,Cu and Ag in Xiongcun porphyry Cu-Au deposits,but poor correlation between Au and Mo. The ore-body is widespread in the phyl-lic and siliconization alterations zone,and Au and Ag mainly occur in chalcopyrite. Xiongcun porphyry mineralization is generally low in depth,and gold-rich porphyry copper deposits tend to be emplaced at levels of 0. 4 ~ 1. 5 km. Mo in Xiongcun copper(gold) deposit mainly occur in molybdenite and more concentrated in the edge of the ore body with a lower content of only one-tenth of Qulong porphyry copper deposit. Xiongcun porphyry deposits are formed in an environment of island arc or similar island arc.