小秦岭大湖金钼矿流体包裹体研究及矿床成因  

Fluid Inclusion Characteristics and Ore Genesis of the Dahu Gold and Molybdenum Deposits in the Xiaoqinling Gold Belt

作　　者：赵海香[1,2] 嵇静[1] 赵智[1] 陈建生[1] 李斌 

机构地区：[1]河海大学地球科学与工程学院,南京210098 [2]南京大学地球科学与工程学院内生金属矿床成矿机制研究国家重点实验室,南京210023 [3]中南大学地球科学与信息物理学院有色金属成矿预测与地质环境监测教育部重点实验室,长沙410083

出　　处：《高校地质学报》2017年第1期72-82,共11页Geological Journal of China Universities

基　　金：国家自然科学基金(41203011);中央高校基本科研业务费专项资金(2016B07814)联合资助

摘　　要：河南灵宝大湖金钼矿床位于小秦岭金矿田,属断裂控制的石英脉矿床。为了解大湖金钼矿矿床成因,对大湖早、中和晚阶段石英中的流体包裹体进行了显微岩相学、显微测温及拉曼光谱分析。分析结果表明:成矿早阶段主要发育水溶液和CO_2-H_2O型包裹体及少量的纯CO_2包裹体;中阶段主要发育CO_2-H_2O、水溶液和含子晶包裹体,纯CO_2包裹体发育很少;晚阶段主要发育水溶液包裹体。早阶段原生CO_2-H_2O型包裹体的均一温度为209~414℃,盐度为1.4%~12.8%;中阶段原生CO_2-H_2O型、水溶液包裹体的均一温度分别为201~380℃和202~333℃,盐度分别为0.6%~12.5%NaCleqv和4.4%~12.2%NaCleqv。估算的早、中阶段CO_2-H_2O型包裹体捕获压力分别为106~217.2 MPa和90.3~128.7 MPa。成矿流体具中高温、中深成、低盐度、富CO_2的特征,表明其为造山型矿床。The Dahu gold deposit in the northern part of the Xiaoqinling gold belt is located in Henan Province.It’s a typical vein deposit controlled by brittle-ductile shear zones.The ore forming process can be divided into the early,middle and late stages based on the cross-cutting relationships and mineral assemblages.Petrographic,fluid inclusion micro-thermometric,and micro Raman spectroscopic analyses reveal four types of fluid inclusions（FIs） in quartz of the Dahu gold and molybdenum deposit,i.e.,CO2-H2O,pure CO2,H2O-solution and daughter mineral-bearing（S type） fluid inclusions.The homogenization temperatures of CO2-H2O inclusions in the early-stage quartz range from 209 ℃ to 414℃ and the salinity ranges from 1.4% to 12.8% NaCleqv.The middlestage quartz contains primary CO2-H2O and H2O-solution,and their homogenization temperatures range from 201380℃ and 202333℃,with the salinity of 0.6%12.5% and 4.4%12.2% NaCleqv respectively.Trapping pressures estimated from the CO2-H2O inclusions are 106217.2 and 90.3128.7 MPa for the early and middle stage,respectively.In short,the characteristics of ore fluids in the early and middle stages are meso-to hypothermal,CO2-rich and low salinity,which are consistent with the properties of metamorphic fluids,whereas the late stage fluids show low salinity,CO2-poor and low temperature.The ore-forming fluid system of the Dahu gold deposit is identical to that of an orogenic-type.

关 键 词：大湖 流体包裹体 造山型矿床 显微测温研究 显微拉曼分析 

分 类 号：P618.65[天文地球—矿床学]