【摘要】 大别山北部石榴辉石麻粒岩是一种基性麻粒岩,岩石中富含有大量CO₂、CH₄、H₂S、H₂O流体包裹体,及含子晶多相包裹体。首次在寄主矿物石榴石、透辉石发现有含固相的多相包裹体。经拉曼光谱及电镜分析,固相部分为石榴石,辉石、重晶石和铁的氧化物;气相成分为H₂O、CO、CO₂、H₂S、H₂、CH₄、C₂H₂等,均一温度分别为950℃、975℃。指示着石榴辉石麻粒岩在形成过程中,在还原气氛下曾经发生过局部深熔作用,产生在组成上近于石榴石、辉石的熔体。这种溶体被正在结晶的石榴石,透辉石所捕获。石榴石中早期的含石榴石子晶+CO₂多相包裹体其CO₂密度为0.65～0.626g/cm³;二相的 CO₂包裹体,CO₂部分的均一温度26～28.2℃,为晚期捕获的低密度CO₂包裹体,密度为0.648～0.688g/cm³。石英中三相H₂O-CO₂包裹体,Th=331～410℃,CO₂-水合物溶化温度7.3°～8.6℃,是一种低盐度包裹体,CO₂部分均一温度:25.7～28℃,CO₂密度0.65～0.698g/cm³为早中期捕获的包裹体。整个岩石中未发现高密度CO₂流体包裹体。表明麻粒岩可以形成在低密度CO₂之中。H₂O-NaCl包体均一温度80～475℃,密度0.36～1.026g/cm³,主要为晚期包裹体,少数高密度H₂O包裹体,为早期捕获的包裹体。通过流体包裹体等容线确立石榴辉石麻粒岩P-T轨迹为更多还原

【Abstract】 Garnet-pyroxene granulites occurring in the Northern Dabie mountain are basic granulites. There are a lot of fluid inclusions of CO2, CH4, H2S, H2O and the multiphase solidphases-bearing. The multiphases inclusions of solidphases-bearing are discovered in garnets and diopsides for the first time. The solid phases were determined as garnet, pyroxene, barite and Fe-oxide by Laser Raman Microprobe and SEM/EDS, and the gas phases as H2O, CO, CO2, H2S, H2, CH4, C2H2 and so on with homogenization temperature of 950℃, 975℃. It indicates that partial anatexis had occurred in the process of forming garnet-pyroxene granulites under reduction condition, and the melt inclusions formed which were catched by carystalling garnets and diosides. Its composition similizes to garnet and pyroxene. Among them, the early stage multiphase inclusions of garnet halite and CO2-bearing, its CO2 density: 0. 65 - 0. 626g/cm3, two phase CO2 inclusions, its partial homogenization temperature: 26-28. 2℃, density: 0. 648-0. 688g/cm3 are late stage low density CO2 inclutions, the three phases H2O-CO2 fluid inclusions in quartz are lower salinity one with Th=331-410℃, melting temperature of ice point: 7. 3 - 8. 6℃ , partial CO2 homogenization temperature: 25. 7 - 28℃, density: 0. 65 - 0. 698g/cm3 which may be early-midlle stage inclusions catched. No high density CO2 inclusions are found in whole rocks. It shows that the granulites are formed under lower density CO2 condition. The H2O-NaCl fluid inclusions in quartz with homogenization temperature: 80-475℃ , density: 0. 36 - 1. 026 g/cm3, mainly are late stage inclusions, and a few of abundent H2O inclusions are early stage ons. By means of isochore curves, the P-T paths of garnet-pyroxene granulites are formed in a clockwise way by isothermal decompression process.更多还原