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Regional occurrence of orthopyroxene‐bearing basic rocks in the Yanai district, southwest Japan: Evidence for granulite‐facies Ryoke metamorphism
Author(s) -
Ikeda Takeshi
Publication year - 2002
Publication title -
island arc
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.554
H-Index - 58
eISSN - 1440-1738
pISSN - 1038-4871
DOI - 10.1046/j.1440-1738.2002.00364.x
Subject(s) - granulite , geology , metamorphism , geochemistry , cordierite , facies , metamorphic rock , hornblende , biotite , metamorphic facies , isograd , pelite , quartz , petrology , geomorphology , paleontology , biochemistry , chemistry , structural basin , catalysis
The present paper is reporting on the regional occurrence of orthopyroxene‐bearing basic rocks from the Ryoke Metamorphic Belt in the Yanai district, southwest Japan. Their localities are confined to the highest‐grade zone of the area (i.e. the garnet–cordierite zone, where garnet coexists with cordierite, K‐feldspar and biotite in pelitic rocks). Orthopyroxene coexists with quartz and hydrous minerals such as biotite, cummingtonite and hornblende, and in some cases with clinopyroxene, suggesting that the highest grade of the Ryoke metamorphism reached a low‐temperature subfacies of the granulite facies, contrary to the upper amphibolite facies as previously asserted.