焦家金矿成矿流体垂向变化特征及对胶东金成矿过程的启示

The Vertical Variation Characteristics of Ore-forming Fluids of the Jiaojia Deposit:Implications for Mineralizing Processes of Gold Deposits in the Jiaodong Peninsula

为探讨焦家金矿成矿流体的时空演化特性,在焦家金矿(1)号和(3)号矿体纵深450 m的剖面上采集矿化样品,对不同阶段、不同深度石英脉中流体包裹体进行显微测温以及成矿流体特征垂向对比研究。结果显示,成矿早阶段石英主要捕获H_(2)O-CO_(2)型包裹体,其完全均一温度为271~359℃,盐度为6.0%~10.0%NaCl_(eqv),XCO_(2)为0.1~0.15。主成矿阶段石英中捕获大量H_(2)O-CO_(2)型、H_(2)O型和CO_(2)型包裹体,它们的完全均一温度为198~315℃,盐度为6.5%~8.5%NaCl_(eqv)。成矿晚阶段石英中只发育H_(2)O单相和气液两相包裹体,其完全均一温度为102~188℃,盐度为0.2%~3.8%NaCl_(eqv)。研究显示,焦家金矿成矿流体与其他胶东金矿成矿流体特征与演化过程一致,且在纵深450 m剖面上保持不变。与前人研究成果对比发现,胶东金矿具有统一的流体来源,但成矿物质显示出更为复杂的来源,应有源于沉积地层的物质加入。

In order to explore the temporal and spatial evolution characteristics of the ore-forming fluid in the Jiaojia gold deposit,samples at various levels with depths of elevations varying from-167 to-600 m were taken from the No.(1)and(3)gold orebodies of the Jiaojia deposit.For undertaking the vertical contrast study of ore-forming fluid characteristics,the microthermometric study of fluid inclusions in quartz veins of different ore-stages from samples collected at different depths has been carried out.The results show that early ore-stage quartzs mainly captured H_(2)O-CO_(2)-type fluid inclusions that had their total homogenization temperatures of 271-359℃,salinities of 6.0%-10.0%NaCl_(eqv),and XCO_(2) values of 0.1-0.15.The main ore-stage quartzs captured a large amounts of H_(2)O-CO_(2),H_(2)O and CO_(2) type fluid inclusions with their total homogenization temperatures of 198-315℃and salinities of 6.5%-8.5%NaCl_(eqv).The late stage quartzs only captured H_(2)O type fluid inclusions that had the total homogenization temperatures of 102-188℃and salinities of 0.2%-3.8%NaCl_(eqv).These microthermometric results suggest that the ore-forming fluid of the Jiaojia gold deposit has the consistent characteristics and evolution process with those of other gold deposits in the Jiaodong Peninsula,and the ore-forming fluid characteristics kept stable within the 450 m ranged vertical profile.Combining with results of previous and this studies,it is believed that gold deposits in the Jiaodong Peninsula should share the common ore-forming fluid source but could contain relatively complicated ore-forming material sources with the addition of various amounts of sedimentary strata-derived materials.