西天山阿希、京希-伊尔曼得金矿床成矿流体包裹体研究及矿化类型探讨

Study on fluid inclusions and discussion on gold mineralization styles of Axi,Jingxi-Yelmend gold deposits in Western Tianshan,Xinjiang

阿希、京希-伊尔曼得金矿床3个主成矿阶段形成的石英中的原生流体包裹体数量少、个体小,包裹体以单液相为主,气液两相者气液比小,一般为5%～10%。激光拉曼光谱成分分析显示液相成分以H2O为主,普遍含有一定量的CO2、CH4;气相中以CO2和CH4为主,含有较高的SO2和N2;一些样品中还出现了C2H4、C6H6、C4H6等有机化合物。其均一温度为90～275oC,成矿流体盐度为0～3.7wB(NaCleq)%,估算的成矿深度为0.40～0.80km左右,属于典型的浅成低温热液型金矿床。其成矿作用与强烈的次生石英岩化关系极为密切,发生了次生石英岩化矿化,形成含金次生石英岩型矿石。

Study on fluid inclusions shows that there are two main types of primary fluid inclusions which are pure aqueous and aqueous existed in hydrothermal quarts in three mineralization stages of Axi, Jingxi-Yelmend gold deposits. These fluid inclusions are very small and sparse, ratios of gas to liquid in aqueous are 5%～10%. Components of these single fluid inclusion in samples were analyzed with a LRM, which indicate that liquids in these fluid inclusions mainly contain H_2O, aside from CO_2,CH_4, chief components of gas in aqueous fluid inclusions are CO_2,CH_4 and much of SO_2,N_2 and small amounts of C_2H_4,C_6H_6,C_4H_6 in two samples.These inclusions have homogenization temperatures generally between 90(~oC) and 275(~oC) and salinities mostly from 0～3.7 wt% NaCleq. The fluid inclusion and geological data suggest that the mineralization took place in depths of 0.40～0.80 km roughly in typical epithermal environment. The metallization was related to intense silicification,resulted of forming secondary quartzite. The auriferous secondary quartzite is one of important ore styles of Axi, Jingxi-Yelmend gold deposits in Western Tianshan.