Petrology of the Basic Granulites from Kodaikanal, South India

Basic granulites occurring as small enclaves and pods within charnockites contain predominantly orthopyroxene, clinopyroxene, hornblende, plagioclase feldspar and quartz. Chemical composition of coexisting orthopyroxene, clinopyroxene, plagioclase and hornblende has been represented in ACF and AFM diagrams. The mineral assemblages and the textural relationships of the basic granulites have been described. Garnet is notably absent in the basic granulites and this is explained as due to lower (< 8 kbar) pressure and relatively magnesian bulk composition.