摘要
The khondalite series, distributing on the border area of Shanxi Prov ince and Inner Mongolia, is predominantly composed of garnet-orthopyroxene-bio ti te-plagioclase gneiss and sillimanite-garnet-biotite-monzonitic or potash fe ldsp athic gneiss. However, the gedrite is firstly discovered in the khondalite serie s of the studied region. According to the diagnostic texture of mineral transfor mation, a complex metamorphic reaction involving gedrite is recognized in rocks of the khondalite series: 6(Mg,Fe)3Al 2Si 3O 12 Gt+ 5SiO 2 Qz+ 2H 2O F= 2(Mg,Fe) 5Al 4Si 6O 22 (OH) 2 Gd+ 3(Mg,Fe) 2Si 2O 6 Opx+ (Mg,Fe) 2Al 4Si 5O 18 Crd Considering the data of genetic mineralogy, thermodynamics and PT estimat ion in connection with available experimental data, the above reaction of the kh ondalite series is characterized by typical decompression. These results have im portant significance for looking into the genetic mechanism and metamorphic dyna mic process of the Archean khondalite series in the Sino-Korea craton.
The khondalite series, distributing on the border area of Shanxi Prov ince and Inner Mongolia, is predominantly composed of garnet-orthopyroxene-bio ti te-plagioclase gneiss and sillimanite-garnet-biotite-monzonitic or potash fe ldsp athic gneiss. However, the gedrite is firstly discovered in the khondalite serie s of the studied region. According to the diagnostic texture of mineral transfor mation, a complex metamorphic reaction involving gedrite is recognized in rocks of the khondalite series: 6(Mg,Fe)3Al 2Si 3O 12 Gt+ 5SiO 2 Qz+ 2H 2O F= 2(Mg,Fe) 5Al 4Si 6O 22 (OH) 2 Gd+ 3(Mg,Fe) 2Si 2O 6 Opx+ (Mg,Fe) 2Al 4Si 5O 18 Crd Considering the data of genetic mineralogy, thermodynamics and PT estimat ion in connection with available experimental data, the above reaction of the kh ondalite series is characterized by typical decompression. These results have im portant significance for looking into the genetic mechanism and metamorphic dyna mic process of the Archean khondalite series in the Sino-Korea craton.
