Q121
Geography (incl. West Bengal)Physiography: Mountains, Plateaus, Plains & Islands
Which one of the following is the oldest rock found in India?
- a.Granite
- b.Bauxite
- c.Khondalite
- d.Andesite
Answer: (C) Khondalite
Khondalite, a metamorphic rock of the Eastern Ghats in Odisha and Andhra Pradesh named after the Khond tribe, is placed with charnockite in the Archaean group, the oldest rock system of India. Granite is the tempting option, since Archaean granites and gneisses also occur, but granite is formed in many geological ages. Bauxite is not a primary rock at all but the ore of aluminium, formed by weathering. Andesite is a volcanic rock named after the Andes.