福建邱村金矿地质特征及矿床成因

The Geological Characteristics and Ore Genesis of the Qiucun Gold Deposit,Fujian Province

为研究福建邱村金矿的矿床成因,对围岩蚀变、矿石矿物成分及流体包裹体进行了研究。围岩蚀变研究表明,金矿化与石英(玉髓)-伊利石-黄铁矿-碳酸盐矿物组合相关,为一套典型低硫型浅成低温热液蚀变组合。电子探针成分分析显示,银金矿中金含量为62%~69%,银含量为28%~33%,金的成色平均为674。包裹体岩相学及显微测温结果显示,含金石英脉中以富液相两相包裹体为主,偶见少量富气相包裹体;富液相两相包裹体的均一温度为180~250℃,盐度为0.5%~3.0%Na Cleq。激光拉曼测试表明,包裹体气相成分以水为主。上述结果均表明邱村金矿床应属于低硫型浅成低温热液矿床。

The Qiucun gold deposit,hosted in the Nanyuan Formation consisting of continental arc volcanic rocks,is controled by NE-NNE trending faults. In order to figure out the geological characteristics and ore genesis of the Qiucun gold deposit,detailed studies of wall rock alteration,ore mineral composition and fluid inclusion were carried out. Wall rock alteration study shows that gold mineralization is closely associated with quartz（ chalcedony）-illite-pyrite-calcite assemblages,which are typical of low-sulfidation epithermal system. EPMA analysis indicate that the electrum consists of62% - 69% gold and 28% - 33% sliver with gold mean fineness of 674. Liquid-rich two-phase aqueous fluid inclusions are dominated in auriferous quartz veins,only minor vapor-rich fluid inclusions occurred in such quartz veins. Liquid-rich fluid inclusions have homogenization temperatures（ Th） of 180-250℃ and salinities of 0. 5%-3. 0% Na Cl equivalent. Laser Raman analysis shows that the vapor phase of the inclusions are mainly H2 O. All the results indicate that the Qiucun gold deposit belongs to a low-sulfidation epithermal deposit.