云南金平龙脖河铜矿床的成矿流体特征

ORE-FORMING FLUIDS OF THE LONGBOHE COPPER DEPOSIT IN JINPING,YUNNAN

龙脖河铜矿床流体包裹体和氢氧同位素研究表明其成矿流体总体上具中温、中高盐度和中偏高密度特征。成矿溶液是高矿化度的Na+-Ca2+氯化物型,主要来源于岩浆水、地下热卤水、变质水混合型。从火山沉积成矿期到热液改造成矿期成矿流体的温度、盐度、压力、密度逐渐降低,前者相对于后者的成矿作用是为中性偏弱酸性环境,后者则酸性氧化性质更加明显,显示其氧化程度和开放程度的增加。

Based on analyses of primary fluid inclusions, hydrogen and oxygen isotopes, it was considered that ore - forming fluids in the Longbohe copper deposit are typical high - degree mineralizing Na ^＋ - Ca^2 ＋ chloride type with intermediate temperature, intermediate - high salinity and interme- diate - high density. The fluids are mainly originated from mixed magmatic, underground thermal brine and metamorphic water. From volcanogenic sedi- mentary metallogenic epoch to hydrothermal metallogenic epoch, temperature, salinity, pressure density of the fluids gradually dropped. Ore -forming process of volcanogenic sedimentary metallogenic epoch was neutral to weak acidic environment comparing with hydrothennal metallogenic epoch, the later period was more obviously an acidic and oxidized condition, and displayed increase of its oxidized and open degree.