Garnet-clinopyroxene intermediate granulites in the St. Leonhard massif of the Bohemian Massif: ultrahigh-temperature metamorphism at high pressure or not?
M Racek, P Stipska, R Powell
JOURNAL OF METAMORPHIC GEOLOGY | BLACKWELL PUBLISHING | Published : 2008
Garnet-clinopyroxene intermediate granulites occur as thin layers within garnet-kyanite-K-feldspar felsic granulites of the St. Leonhard granulite body in the Bohemian Massif. They consist of several domains. One domain consists of coarser-grained coexisting ternary feldspar, clinopyroxene, garnet, quartz and accessory rutile and zircon. The garnet has 16-20% grossular, and the clinopyroxene has 9% jadeite and contains orthopyroxene exsolution lamellae. Reintegrated ternary feldspar and the Zr-in-rutile thermometer give temperatures higher than 950°C. Mineral equilibria modelling suggests crystallization at 14kbar. The occurrence and preservation of this mineral assemblage is consistent with..View full abstract