geology of western ghat

The Western Ghats are not true mountains, but are the faulted edge of the Deccan Plateau. They are believed to have been formed during the break-up of the super continent of Gondwana some 150 million years ago[citation needed]. Geophysicists Barren and Harrison from the University of Miami advocate the theory that the west coast of India came into being somewhere around 100 to 80 mya after it broke away from Madagascar. After the break-up, the western coast of India would have appeared as an abrupt cliff some 1,000 meters in height[citation needed]. Soon after its detachment, the peninsular region of the Indian plate drifted over the Réunion hotspot, a volcanic hotspot in the Earth's lithosphere near the present day location of Réunion[citation needed]. A huge eruption here some 65 mya[citation needed] is thought to have laid down the Deccan Traps, a vast bed of basalt lava that covers parts of central India. These volcanic upthrusts led to the formation of the northern third of the Western Ghats. These dome-shaped uplifts expose underlying 200 mya[citation needed] rocks observed in some parts such as the Nilgiri Hills. Basalt is the predominant rock found in the hills reaching a depth of 3 km (2 mi). Other rock types found are charnockites, granite gneiss, khondalites, leptynites, metamorphic gneisses with detached occurrences of crystalline limestone, iron ore, dolerites and anorthosites. Residual laterite and bauxite ores are also found in the southern hills.