【摘要】 棉田金铜矿床是受断裂构造和中性侵入体联合控制的以金、铜为主的多金属矿床。笔者在对该区地质调查的基础上,运用红外光谱分析和显微测温技术对成矿流体进行研究,发现该区围岩蚀变以绢云母化和青磐岩化最为普遍,并将成矿阶段分为4个阶段:黄铁绢英岩阶段、石英--黄铁矿阶段、多金属硫化物阶段和石英--碳酸盐阶段;对应的均一温度为320℃～360℃、280℃～320℃、200℃～280℃和200℃～240℃;其中主成矿阶段为第二、三阶段,主成矿温度为200℃～320℃,这也是热液中水和二氧化碳含量最高的阶段。流体盐度为1.91～13.40(wt%,NaCl),密度为0.69～0.95g/cm3,具低盐度和低密度的特点;成矿深度为0.8～1.5 km,具浅层成矿的特点;氢氧同位素分析,δ18OH2O的值为-4.7×10-3～5.83×10-3,δDH2O的值为-89×10-3～-124×10-3,说明成矿流体主要为岩浆水,含少量大气水。综合研究表明,棉田金铜矿床属于浅成中温岩浆热液型矿床。更多还原

【Abstract】 Miantian gold-copper deposit is a gold-copper-based multi-metal deposit controlled by faults and neutral intrusions.On the basis of geological survey,we studied the ore-forming fluids by infrared spectroscopy and micro themometry.The results showed that the wall rock alteration was dominated by sericitization and propylitization,and the mineralization consisted of four stages,including the beresite stage,quartz-pyrite stage,polymetallic sulfides stage and quartz-carbonate stage.Correspondingly the homogenization temperatures were 320℃~360℃,280℃~320℃,200℃~280℃ and 200℃~240℃,in which the second and third were the main mineralization stages,corresponding homogenization temperatures from 200℃ to 320℃).At the same time there were the highest contents of H2O and CO2 in the main mineralization stages.Salinity of fluid varied between 1.91% and 13.40%(wt%,Nacl) and density was 0.69 ~0.95 g/cm3,with obvious characteristics of low salinity and density.The main ore-forming depth was from 0.8 km to 1.5 km,which indicated the epizonal characteristics.Based on the compositional analytical results of fluid inclusions,the values of δ18OH2O and δDH2O were-4.7×10-3~5.83×10-3 and-89×10-3~-124×10-3,which illustrated that the ore-forming fluids mainly originated from magmatic hydrothermal along with a small amount of atmospheric water.Miantian gold-copper deposit belonged to medium temperature epizonal magmatic-hydrothermal deposit.更多还原