Minerals and the mineral belts of India
A mineral is a natural substance with a definite chemical and physical make-up. Minerals are unevenly spread. Most metallic minerals are in the old crystalline rocks of the Peninsular plateau; coal is mostly in the Damodar, Mahanadi, Son and Godavari valleys; petroleum is in sedimentary basins of Assam, Gujarat and Mumbai High.
Three mineral belts
- North-eastern plateau region: Chotanagpur (Jharkhand), Odisha plateau, West Bengal and parts of Chhattisgarh. Rich in coal, iron ore, manganese, mica and bauxite.
- South-western plateau region: Karnataka, Goa and nearby Tamil Nadu uplands and Kerala. Iron ore, manganese, limestone, and some bauxite; lignite in Neyveli.
- North-western region: along the Aravalli in Rajasthan and part of Gujarat. Copper, zinc, and building stones like sandstone, granite and marble; gypsum; petroleum and gas in Gujarat.
The Himalayan belt and the Assam valley also have some minerals, and there are offshore oil deposits.
Metallic and non-metallic minerals
Iron ore: India has large reserves of good haematite and magnetite. Main areas: Odisha, Jharkhand, Chhattisgarh, Karnataka and Goa. It is the base of the steel industry.
Manganese: used to make iron and steel hard, and in alloys. Main areas: Odisha, Karnataka, Madhya Pradesh, Maharashtra.
Bauxite: the ore of aluminium, found in laterite rocks on plateaus. Main areas: Odisha, Jharkhand, Gujarat, Chhattisgarh, Maharashtra.
Copper: good conductor of electricity, used for wires and electronics. Main areas: Jharkhand (Singhbhum), Madhya Pradesh (Balaghat), Rajasthan (Khetri).
Mica (non-metallic): splits into thin, clear sheets; an excellent insulator used in electrical and electronic goods. Main areas: Jharkhand, Andhra Pradesh, Rajasthan.
Conventional energy: coal, petroleum and natural gas
Coal gives most of India's electricity. Gondwana coal (about 200 million years old) is found in the Damodar valley (Jharia, Raniganj, Bokaro), Mahanadi, Son and Godavari valleys. Tertiary coal (younger) is in the north-east. Lignite is mined at Neyveli in Tamil Nadu.
Petroleum is a mix of hydrocarbons found in sedimentary rocks, often trapped under folds (anticlines). Main fields: Digboi and others in Assam, Ankaleshwar and Kalol in Gujarat, and offshore Mumbai High. Refineries turn crude oil into petrol, diesel and many other products.
Natural gas is found with or without oil. It is cleaner than coal. Gas comes from Mumbai High, the Krishna–Godavari basin and others, and is carried by pipelines.
Non-conventional energy sources
- Nuclear: uranium and thorium (thorium from monazite sands of Kerala) are split in reactors. Plants: Tarapur, Rawatbhata, Kalpakkam, Narora, Kaiga, Kakrapar, Kudankulam.
- Solar: sunlight is changed to electricity by photovoltaic panels or used as heat. Western India (Rajasthan, Gujarat) has great potential.
- Wind: moving air turns turbines. Good in Gujarat, Tamil Nadu, Rajasthan, Maharashtra and Karnataka.
- Tidal and wave: rising and falling sea water turns turbines. Potential on the west coast (Gulf of Khambhat, Gulf of Kachchh) and the Sundarbans.
- Geothermal: heat from inside the Earth; an experimental project at Manikaran in Himachal Pradesh, and hot springs in Ladakh.
- Bio-energy: energy from farm waste, dung, city and industrial waste; it gives power and gas and reduces garbage.
These sources are renewable, spread widely, cleaner and cut dependence on imported oil, though they need high starting cost.
Conservation of mineral resources
Minerals are non-renewable: they take millions of years to form. For sustainable development we must keep some for the future.
- Use renewable energy (solar, wind, tidal) in place of coal and oil.
- Recycle scrap metals like iron, aluminium and copper.
- Use substitutes for scarce metals.
- Use better mining and processing methods to reduce waste.
- Export less of scarce strategic minerals so that reserves last.
Key formulas and definitions
- Mineral: natural substance with a definite chemical and physical make-up
- Metallic: iron ore, manganese, bauxite, copper; non-metallic: mica, limestone
- Conventional energy: coal, petroleum, natural gas (exhaustible)
- Non-conventional: nuclear, solar, wind, tidal, geothermal, bio-energy
- Years a reserve lasts ≈ reserve ÷ net yearly use
- Net use = use × (1 − recycling fraction)
Worked examples
1. A mine has 1,000 units of ore and uses 10 units a year. How long will it last?
1,000 ÷ 10 = 100 years.
2. If 50% of the metal is recycled, what is the new net use and how long will it last?
Net use = 10 × 0.5 = 5 units. 1,000 ÷ 5 = 200 years. Recycling doubles the life.
3. Why is the Chotanagpur plateau called the storehouse of minerals?
Its very old crystalline rocks hold coal, iron ore, manganese, mica and bauxite close together, which supports steel and other heavy industries nearby.
4. Why is Rajasthan suited for solar energy?
It has many clear, sunny days, strong sunshine and large open land.
5. Why does petroleum occur in sedimentary rocks, not in the Deccan lava?
Oil formed from buried sea life in layered sediments; lava rocks formed from molten rock and have no such remains.
6. Give two reasons India is building more wind and solar power.
They never run out and do not pollute; they cut imports of oil and coal and can be set up in villages far from the grid.
Common mistakes
- Calling mica a metallic mineral. It is non-metallic.
- Saying nuclear energy is fossil fuel. It comes from splitting uranium/thorium atoms.
- Mixing Gondwana and tertiary coal. Gondwana is older and found in peninsular river valleys; tertiary is in the north-east.
- Thinking non-conventional means 'free of cost'. It saves fuel, but needs high investment to start.