Pillowed Spilitic Basalts from the Tadpatri Formation of Cuddapah Basin

Pillow structures are noticed in the spilitised basalts occurring within the shales of Tadpatri Formation indicating subaqueous eruption as against the traditional notion of subaerial volcanism in Cuddapah basin. The basalt is enriched in alkalis and silica and depleted in calcium and magnesium. The pillows are separated by a black siliceous inter-pillow material. The pillowed basalt is under1ain by a massive Java with a thin intervening bed of aphanitic rock and nodular limestone. This pillowed and massive lava flow appears to extend for long distances in the Cuddapah basin.