High-pressure granulite facies

Index Minerals

Sapphirine, Osumilite

Required Geological Setting

Accretionary complexes + Middle-P metamorphic rocks

Occurrence

Metamorphic rocks formed by regional metamorphism in the following condition: more than 700 degree and 1.0-1.5 GPa (30-50 km depth). A metamorphic facies formed in subduction zones. High-pressure granulite facies metamorphic rocks are in Barrovian-type middle-P metamorphic rocks.

Change of mineral assemblages

• [ Extinct ] Garnet, Cordierite
• [ Appear ] Sapphirine, Osumilite

Mineral Assemblages

• [ Felsic Rocks ] Quartz, Plagioclase, K-feldspar, (Hornblende, Biotite)
• [ Mafic Rocks ] Clinopyroxene (Diopside), Plagioclase, (Orthopyroxene (Hypersthene))
• [ Ultramafic Rocks ]
• [ Mudstone ] Sapphirine, Orthopyroxene (Hypersthene), Sillimanite, K-feldspar, Quartz, (Osumilite)
• [ Laterite ]
• [ Bedded Mn ]
• [ Carbonate Rocks ]