Geochemistry and Significance of Mafic-Ultramafic Rocks from the Southern Part of the Holenarasipur Schist Belt, Karnataka

The ultramafic rocks of Holenarasipur schist belt show micro-spinifex texture, deformed pillow lava-like structures and contain interbedded fuchsite-quartzite. Compositionally the mafic-ultramafic rocks are similar to peridotitic, pyroxenitic and basaltic komatiites. Available data exhibit a gap between 20 and 30% MgO content, which suggests discontinuity in their composition. A two stage melting model is projected to explain this compositional gap. The abundance of komatiitic mafic-ultramafic rocks supports the view that the Holenarasipur schist belt is a true greenstone belt.