PALKONDA HILLS

series of ranges in southern Andhra Pradesh state, southern India. The hills trend northwest to southeast and form the central part of the Eastern Ghats. Geologically they are relics of ancient mountains formed during the Cambrian Period (570 to 505 million years ago) that were subsequently eroded by the Penner River and its tributaries. The Punchu and Cheyyeru rivers join in a spectacular confluence in a gorge in the corridor between the Velikonda and the Palkonda Hills. Formed of quartzites, slates, and lavas, the P alkondas reach an elevation of 3,000 feet (900 m) in the south. The valleys between the mountains are drained by streams, many of which, having been dammed for storage tanks, provide irrigation for cultivation. The main crops are jowar (sorghum) and peanuts (groundnuts).