Carbonate-Orthopyroxene-Chrome Tremolite Rocks (Sagvandites) from Mavinahalli, Mysore District, Karnataka State

Carbonate-orthopyroxene-chrome tremolite rocks and their variants occur in close association with the ultramafics emplaced into the high grade metamorphic terrain of Sargur schist complex, around Mavinahalli village. The country rocks exhibit mineral assemblages typical of upper amphibolite to lower granulite facies of metamorphism and show signs of extensive migmatisation. The above mineral assemblages are very much similar to the rock types termed as 'Sagvandites', originally reported from Norway. Field evidences, petrography and petrochemistry of these rocks clearly show that they represent original ultramafic rocks metasomatically recrystallized due to circulating CO₂ (+Si0₂) rich solutions, at metamorphic temperatures of 630°C and at pressures of at least 6 kb.