摘要
对青海赛什塘铜矿床内与成矿有关的矽卡岩中石榴子石、透辉石及硫化物石英脉中流体包裹体的岩相学、显微测温学和显微激光拉曼光谱分析等的研究结果表明,流体包裹体有富液相、富气相和含子矿物多相包裹体3种类型;早期矽卡岩阶段均一温度436~562℃,盐度为34 wt%~45wt%NaCl eqv.,代表了高温、高盐度岩浆流体;退变质阶段均一温度322~419℃,盐度为15wt%~39 wt%NaCl eqv.;硫化物阶段均一温度235~366℃,盐度5wt%~36wt%NaCl eqv.。激光拉曼光谱分析结果表明,包裹体中气相成分以CH4、H2S、CO2和H2O为主。成矿流体属于中高温、高盐度的NaCl-H2O-CO2-CH4体系,在290~360℃之间发生了强烈的流体沸腾作用,导致大量的金属硫化物沉淀,成矿流体的沸腾作用是导致铜矿床形成的重要因素。
The fluid inclusions in the Saishitang Cu deposit can be classified into liquid-rich two-phase, gas-rich two-phase and daughter mineral-bearing polyphase types. According to studies of petrography, microthermometry and laser tkaman spectrographic analyses of fluid inclusions in garnet and diopside from skarn and sulfide-rich quartz veins, the fluid inclusion homogenization temperatures and salinities of the early skarn stage vary in the range of 436℃-562℃ and 34 %-45%wt%NaC1 eqv. respectively, indicating that the fluid is dominated by magmatic water characterized by high temperature and high salinity; the fluid inclusion homogenization temperatures and salinities of the retrogressive metamorphic stage vary in the range of 322℃- 419℃ and 15%-39% wt%NaC1 eqv. Respectively; the fluid inclusion homogenization temperatures and salinities of the sulfide stage vary in the range of 235℃-366℃ and 5%-36%wt%NaC1 eqv. respectively. Laser Raman spectrogtaphic analyses show that the gas phase components of fluid inclusions are mainly composed of CH4, H2S, CO2 and H20, and the ore-forming fluids belong to the NaC1-H20-CH4-H2S-CO2 system. The boiling event of ore-forming fluid occurred at temperatures of 290℃-360℃, resulting in the formation of massive metal sulfides. The fluid boiling was favorable for the formation of the Saishitang Cu deposit.
出处
《中国地质》
CAS
CSCD
北大核心
2013年第2期580-593,共14页
Geology in China
