印度尼西亚Ciemas浅成低温热液型金矿矿物学特征分析

Mineralogical Characteristics of Epithermal Hydrothermal Type Gold Deposit in Ciemas,Indonesia

为了弄清Ciemas金矿矿床成矿地质条件,针对矿石矿物组合、元素分布特征、流体包裹体等问题,进行了矿物学、电子探针及矿物包裹体综合研究。研究表明:矿石矿物组合包括自然金、黄铁矿、毒砂、黄铜矿、锑铅银矿、方铅矿和磁黄铁矿等,蚀变作用主要为硅化、绢云母化、黄铁矿化、绿帘石、泥化等;金与黄铁矿、毒砂关系密切,黄铁矿Fe、S都亏损,相对更亏损Fe,钴镍比值平均13.25,Co含量远大于Ni;矿床主成矿期温度240~320℃,成矿初始深度0.33~1.73 km,氢、氧同位素特征显示成矿流体主要来源于原生岩浆水和极少量的大气降水。矿床矿石具有典型的低温热液矿物组合特征,矿床可能受角闪石英斑岩建造叠加所致,矿床成矿条件符合浅成低温热液金矿床一般特征。

In order to clarify the metallogenic geological conditions of the Ciemas gold deposit,a comprehensive study of mineralogy,electron probe and mineral inclusions was carried out for the problems of ore mineral assemblage,element distribution characteristics and fluid inclusions.The results show that the ore mineral assemblages include natural gold,pyrite,arsenopyrite,chalcopyrite,stibnite,galenite and pyrrhotite.The alteration is mainly silicification,sericitization,pyritization,epidote and argillization.Gold is closely related to pyrite and arsenopyrite,pyrite Fe,S are depleted,relatively more depleted Fe,cobalt-nickel ratio average 13.25,Co content is much greater than Ni;the temperature of the main ore forming period is 240~320℃,and the initial ore-forming depth is 0.33~1.73 km.The hydrogen and oxy⁃gen isotope characteristics show that the ore-forming fluid is mainly derived from primary magmatic water and a small amount of atmospheric precipitation.The ore of the deposit has typical characteristics of low temperature hydrothermal mineral assemblage.The deposit may be caused by the superposition of hornblende quartz porphyry construction.The metallogenic conditions of the deposit conform to the general characteristics of epithermal gold deposits.