Characteristics and petrogenesis of granulite enclaves in S-type granites in the junction of Guangdong and Guangxi Provinces

摘要: Granulite enclaves in S-type granites the junction of Guangxi and Guangdong are homoeogene ones have an assemblage plagioclase + quartz biotite hypersthene±garnet±K-feldspar. The granulites define a narrower range total REE contents (135.95~268.83μg/g) LREE / HREE ratios (1.85~5.70) patterns with uniform shapes, indicating their similarities lower crust. Rb-Sr isochron age for is 638~813Ma, 0.7151~0.7152 initial Sr/Sr ratio. Temperature pressure metamorphic peak period calculated to be 781 °C~883°C 0.527~ 0.709GPa, corresponding those middle data mentioned above lead suggest that representative crust formed round about late Proterozoic era. In addition, evidences lithology, mineralogy geochemistry show southwest by regional metamorphism influenced thermal dome, while southeast dynamothermal metamorphism.