吉林延边闹枝金矿床地质特征及矿床成因

闹枝金矿床地处延边—东宁金矿带西段,为一主体产于海西期花岗闪长岩体内的石英脉型矿床。矿床地质特征及含金石英脉内流体包裹体研究结果表明,该区含金石英脉中主要发育气液两相及少量的含子矿物三相、气相--富气相包裹体。气液两相包裹体均一温度为283.5℃～375.9℃,盐度为3.4～8.13 wt%NaCl;富气相包裹体均一温度为416.5℃～431.6℃;含NaCl子矿物三相流体包裹体均一温度为303.9℃～393.2℃,盐度为38.21～45.3 wt%NaCl。包裹体氢、氧同位素分析结果表明,成矿流体以岩浆热液为主,可能混有少量大气降水。矿床成因属中温岩浆热液金矿床。

Geological characteristics and genesis of Naozhi gold deposit in Yanbian area,Jilin Province

Naozhi gold deposit located in the western sector of Yanbian—Dongning gold metallogenic belt,is a quartz vein type deposit occurred in Hercynian granodiorite.The analysis results of geological characteristics and the fluid inclusions in auriferous quratz veins show that the main types of fluid inclusions developed in auriferous quartz vein are gas-liquid two-phase,and a little daughter mineral-bearing three-phase as well as vapor phase fluid inclusions.The homogenization temperature of gas-liquid two-phase fluid inclusions is 283.5 ℃~375.9 ℃,with salintity 3.4~8.13 wt%NaCl;the homogenization temperature of vapor phase fluid inclusions is 416.5 ℃~431.6 ℃;and the homogenization temperature of NaCl daughter mineral-bearing three-phase fluid inclusions is 303.9 ℃~393.2 ℃,with salinity 38.21~45.3 wt%NaCl.The oxygen and hydrogen isotopes of fluid inclusions indicate that the ore-forming solutions mainly derived from magmatic fluids which mixed with a small amount of meteoric water.The gold deposit belongs to medium temperature magmatic hydrothermal type in origin.