Kerala Geology and Mineral Resources

Kerala was an integral segment of the sub-continent in the Trecambrian' phase of geological time approximately about 600 million years ago. Except the narrow strip of coastline, no other part of the state was submerged in the sea. The midland and the high ranges were composed of "Precambrian rocks-chiefly Char-nockites, Khondalites and different gneisses." Rocks of this kind are used for buildings. The coastal sedimentary rocks comprise "limestones, sandstones, clays and shales belonging to the older Quilon series and ferruginous sandstones, clays and occasional lignite patches belonging to the younger Varkalai series." Both represent the Tertiary age. The Kerala coast, which was once submerged, came to be thrown up at the end of the" Tertiary age, when laterisation of the sedimentary rocks also began.

Kerala has a wide range of minerals and for purposes of the study of minerals the state may be divided into four longitudinal zones. The zone which is at the extreme east is characterised by deposits of iron ore, crystalline limestone, mica, graphite, chrysoberyl etc. To the west of it is the second zone, which contains deposits of bauxite, clays and laterite. In between this zone and the beach zone is the third one, which shows deposits of clay, lignite and sedimentary limestone. The coastline is a treasure house of rich deposits of rare-earth mineral sands and glass' sands.

Iron Ore
There is 72 million tonnes of iron ore in the state, containing 40 per cent iron. It is nearly concentrated in the Kozhikode district. Malappuram district also accounts for a minor share of iron deposits. Kozhikode district is ideally suited for the manufacture of iron and steel.

Crystalline Limestone
25 million tonnes of limestone has been estimated in the reservior of Kerala. The concentration is in the Palaghat district. This gives the promise of cement factories in the district.

Lime Shell
Lime shell constitutes the harvest of backwaters and estuaries of rivers pining Vembanad, Ashtamudi, Kodun-galloor, Ponnani and Chawghat lakes. It is also found at Kadalundi, Elan-thur and Kasargod. At Payyannur also it is available. This is utilised for the manufacture of white portland cement and calcium carbide.

Graphite
Graphite abounds in the Idukki district. Its mining did not progress as other minerals.

Mica
Two types of mica, phlogopite and muscovite mica are available in Kerala. But mining has not advanced so far.

Chrysobery
So far no reserves of chrysobery have been found though proof of its existence has been established.

Bauxite
About 11 million tonnes of bauxite have been located, 8 in the Cannan-ore district and 3 in the Trivandurm and Quilon Districts.

Clays
Kerala has large deposits of clay, which is the finest in the country. The districts which have big reserves are Trivandrum, Quilon, Alleppey, Er-nakulam, Kozhikode and Cannanore. Kerala has the finest china clay or Kaolin in the country, with reserves of 80 million tonnes. This holds out the possibility of the manufacture of high tension insulators, sanitary wares, crockery and glazed tiles. Besides an inferior type of clay is also found in many places and is being used for the manufacture of tiles and bricks.

Placer Deposits
Stretching along the coastline of Keralafrom Nindakara to Kayamkulam, there are large deposits of rare sand containing 35 million tonnes of Ilmenite, 3 million tonnes of rutile, one million tonnes of monozite and 0.7 million tonnes of borozhite. These have not been fully harnessed for the tremendous possibilities most of these rare minerals hold out. With the advent of the atomic era, Kerala has shot into prominence as a pride of place in India.

Glass Sand
Along the Kerala coast is found large deposits of silica, used for the manufacture of glass. Their concentration is found in the Alleppey district. This source has been tapped for several years now.