Salem District Mineral Foundation Trust
Salem is a Geologist’s paradise, surrounded by hills and the landscape dotted with hillocks. The district is rich in mineral deposits like Magnesite, Bauxite, Granite, Limestone, Quartz, and Iron ore. Mining and allied industries such as Cement Industry, Refractory Bricks manufacturing, Smelting Plant, etc., thrive well.
Crystalline rocks of Archaean to late Proterozoic age occupy over 80% of the area of the state of Tamil Nadu, while the rest is covered by Phanerozoic sedimentary rocks, mainly along the coastal belt and in a few inland river valleys. The hard rock terrain comprises predominantly of Charnockite and Khondalite groups and their migmatitic derivatives, supracrustal sequences of Sathyamangalam and Kolar groups, and Peninsular Gneissic Complex (Bhavani Group), intruded by ultramafic-mafic complexes, basic dykes, granites, and syenites.
The sedimentary rocks of the coastal belt include fluviatile, fluvio-marine, and marine sequences, such as Gondwana Supergroup (Carboniferous to Permian and Upper Jurassic to Lower Cretaceous), marine sediments of Cauvery basin (Lower Cretaceous to Paleogene), Cuddalore /Pannambarai Formation (Mio-Pliocene), and sediments of Quaternary and Recent age.
Bauxite, ore of Aluminium, occurs in the Shevaroy hills of Yercaud Taluk. The Shevaroy hills are made up of Charnockite group rocks interbedded with metasedimentary units, cut across by dolerite dykes. Low-grade bauxite is found up to a depth of 2m, followed by ferruginous clay.
Kanjamalai: The Iron ore deposits in Kanjamalai hill are of Banded Magnetite Quartzite. The deposits occur at three levels, with the first band having an iron content of 33-39% Fe and reserves of 99.3 million tonnes.
Godumalai: The Iron ore deposits in Godumalai are located in a ridge with tightly folded bands. The average Fe content is 34%, and estimated reserves range from 60 to 70 million tonnes.
Found in Sankari Taluk, this crystalline limestone of Precambrian age is extensively used for cement production. The deposits maintain structural conformity with the surrounding granitic mass.
Found in the Chalk Hills of Salem over 17 sq. km. Magnesite is mined by industries like Burn & Co (SAIL Refractory Company Ltd), TANMAG, and others, providing high-quality raw materials for industrial use.
Multi-Colour Granite: Imperial White and Tippu White granite formations are found in Edappadi, Sankari, Attur, and Yercaud, widely quarried for construction.
Black Granite: Found in Attur, Gangavalli, Mettur, and Yercaud, used for ornamental and construction purposes.
Found in Sankari, Omalur, and Mettur Taluks, these deposits are associated with granitic pegmatites. Quartz is usually colorless or milky white, while feldspar appears pink or flesh red.
Dunite, an ultrabasic igneous rock, is found in Chalk Hills, Salem. It consists mainly of olivine and is associated with magnesite.
Found in Periyasoragai, Aranganur, Tholasampatty, Marakottai, and Kongupatty, these deposits are alteration products of magnesium-bearing minerals.
Found in Sankari Taluk, calcite occurs in large masses due to the recrystallization of limestones.
Charnockite is mainly used as rough stone and is being quarried for road metals, jelly, and making of M-sand.
Gravel occurs in Salem, Sankari, Mettur, and Attur Taluks. It is categorized based on particle size from granule- to boulder-sized fragments.