广东梅子冲铅锌钨多金属矿床流体包裹体特征及成矿作用

Characteristics of Fluid Inclusions and Metallogenesis of the Meizichong Pb-Zn-W Polymetallic Deposit in Guangdong Province

梅子冲铅锌钨多金属矿床位于广东省韶关市一六矿区。野外调查和室内显微镜鉴定表明,梅子冲矿床成矿作用分为两期五阶段,第一期为矽卡岩期,可以分为早期矽卡岩阶段(A1)、晚期矽卡岩阶段(A2)和钾长石白钨矿阶段(A3);第二期为热液期,可以分为石英硫化物阶段(B1)和石英碳酸盐阶段(B2)。矿体的石英和白钨矿中含有富液相的气液两相流体包裹体,地质特征结合包裹体测温资料表明,成矿温度介于207℃~449℃,盐度为1.16%~12.4%,反映矿床形成于中-高温环境。成矿流体特征及成矿温度的演化表明,A1+A2至A3阶段的流体混合作用可能导致了白钨矿的形成,A3至B1阶段的流体混合作用可能促进了铅锌矿的形成。

The Meizichong Pb-Zn-W polymetallic deposit is located in the Yiliu mining area, Shaoguan, Guangdong Province. Field geological investigations and microscope characteristics suggest that the mineralization of this deposit can be divided into 2 episodes, namely skarn episode（A） and hydrothermal episode（B）. The former can be subdivided into early skarn stage （A1）, late skarn stage （A2） and K-feldspar-tungsten stage （A3）, while the latter is subdivided into quartz-sulfide stage （B1） and quartz-carbonate stage （B2）. Liquid-rich inclusions were observed in quartz and tungsten from ores. Geological characteristics and micro-thermometric data show that ore-forming temperatures range from 207℃ to 449℃, while salinities range from 1.16% to 12.4%, indicating that the deposit was formed in a medium-high temperature environment. The fluid mixing from A1＋A2 stage to A3 stage might lead to the W precipitation and the fluid mixing from A3 stage to B1 stage might result in the Pb-Zn precipitation.