Geology in Kerala. The State is mainly comprised of crystalline rocks such as charnockites, khondalites, gneisses and Dharwar schists of Precambrian age. The Charnockites are exposed in all districts, khondalites and gneisses are concentrated in the southern part of the State and Dharwar schists and gneisses are exposed in the northern part whereas intrusive granites and dolerites occur in some parts of the State only. There are a number of major faults and fractured zone in Wayanad, Palakkad, Kasaragod, Malappuram etc. Yield of wells which are located along these lineaments are likely to be high.