Petrochemistry of a Gametiferrous Chlorite Schist Horizon from the Sandur Schist Belt, Karnataka

Petrology and mineral chemistry of garnetiferrous chlorite schists belonging to Deogiri formation in the Sandur schist belt have been studied. Mineral assemblages and chemical data on muscovite, biotite, chlorite, garnet from the Deogiri chlorite schists indicate low grade regional metamorphism under greenschist facies condition. Mineralogy of the metabasics associated with Deogiri chlorite schists and with the overlying Donimalai formation in this region, except near the peripheral contacts, also suggest greenschist facies metamorphism for the schist belt. Mineralogy and chemistry of Deogiri metabasalts indicated ocean floor type of alteration/metamorphisrn for the Deogiri metabasalts. Rocks close to the granite contact have seemingly undergone an episode of thermal metamorphism which is distinct from the regional metamorphism of the entire schist belt and possibly isolated both in space and time.