麻粒岩相变质流体及麻粒岩相岩石成因  

Fluid in granulite facies and petrogenesis of granulite facies

作　　者：余能[1] 金巍[1] 龙晓平 

机构地区：[1]吉林大学地球科学学院,吉林长春130026

出　　处：《世界地质》2004年第4期321-325,共5页World Geology

基　　金：中国地质调查局资助项目(200113900070);教育部科学技术研究重点项目(02087)联合资助

摘　　要：流体在麻粒岩相地体形成过程中所扮演的角色是有争议的。麻粒岩相变质流体目前的研究成果可归纳为碳变质模式、无流体变质模式和高盐度流体变质模式。碳变质模式强调幔源CO2在麻粒岩形成过程中起着非常重要的作用,这一模式在许多麻粒岩相地体得到了肯定。但碳、氧稳定同位素的不均一现象、峰期矿物组合热力学计算结果以及富CO2流体对硅酸盐的搬运能力低使碳变质受到了质疑。无流体变质模式强调部分熔融降低H2O活度的绝对重要性,但却无法解释普遍存在的麻粒岩相原生富CO2包裹体。而高盐度流体变质模式的确有潜在的优势,如低H2O活度、较强的碱金属、LILE及硅酸盐的搬运能力,但这一理论需要进一步证实。The role of fluid in granulites facies metamorphism is controversial. The researches of fluid in granulites facies can be concluded as carbonic metamorphism,fluid-absent metamorphism and hypersaline fluids metamorphism. That the popular carbonic metamorphism in mantle-derived CO2-rich fluid plays an important role was favoured for many observations reported from granulite facies. Commonly heterogeneous and localized oxygen and carbon isotope,the parameters based on phase equilibrium analysis and the doubtful capacity of CO2-rich fluid to solute silica should be relatively uniform in the carbonic metamorphism. Fluid-absent metamorphism in which emphasized that the decrease of H2O activity can be accomplished by absorption of H2O into anatectlic melts,but it is unable to explain prevalent CO2-rich fluid inclusion in granulites facies. Hypersaline fluid metamorphism has potentialities of low H2O activity,high alkali mobility and efficient LILE and silica transportation and it should be testified by more researches.

关 键 词：麻粒岩相 CO2 流体包裹体 变质作用 

分 类 号：P581[天文地球—岩石学]