Class 10 Geography Notes Chapter 5 ‘Minerals and Energy Resources’: The Chapter Notes given here are for a quick revision of the chapter ‘Minerals and Energy Resources’. These notes are in addition to our other set of notes which are more comprehensive and exhaustive and you can download or buy them from this website.
Importance of Minerals, Their Classification and Occurrence in Various Formations
What are minerals and their significance in everyday life?
Minerals in our daily life
- The objects that we use daily are made of metals.
- Metals are extracted from minerals after refinement.
- Minerals are present in ores that are found in rocks.
Minerals as indispensable part of our life
- Everything that we use is made of minerals.
- From pins and pens and pencils to buildings and bridges, things we use are made of minerals.
- Railway lines, pavements of roads, machinery and tools that we use are made of minerals.
- Minerals are also used to manufacture trains, ships, aeroplanes and other vehicles. These vehicles run on the power resources that are derived from the earth such as petroleum and natural gas.
- Minerals have been used throughout human history. We use minerals for livelihood, decoration, religious ceremonies.
Minerals in the toothpaste
- The toothpaste that we use daily also contains many minerals.
- Each mineral in the toothpaste has a specific function.
- Minerals like silica, limestone, aluminium oxide and various phosphates help in cleaning the teeth.
- Fluoride is obtained from the mineral fluorite and is used to reduces the risk of cavity formation in the teeth.
- Titanium oxide, which is made up of rutile, ilmenite and anatase, gives white colour to the toothpaste.
- The sparkle that we see in the toothpaste comes from mica particles.
- The tube that contains the paste and the toothbrush are made of plastic, which is obtained from the mineral petroleum.
All living things need minerals
- Minerals are a vital part of our lives.
- Our mineral intake through food is only 0.3% of our total intake of nutrients.
- Without those minerals, 99.7% of the food we eat would not be utilised by our body.
Meaning of mineral
- Minerals are defined as homogenous, naturally occurring substances with a definable internal structure.
- Minerals are found in different forms in nature.
- They may occur in the hardest form such as diamonds as well as in the softest form such as talc.
- Rocks are formed of minerals.
- Some rocks contain one mineral, such as limestone, while some rocks contain more than one mineral, such as granite.
Geologists and minerals
- Geologists have identified over 2,000 minerals to date.
- Geologists study the formation, age and physical and chemical compositions of minerals.
- They classify minerals on the basis of colour, hardness, crystal forms, lustre and density.
- Geographers study minerals to gain better understanding of landforms.
- Distribution of minerals and the economic activities related to them are areas of interest for geographers.
How are minerals formed and extracted?
- Minerals are found in ores.
- Ore is a mixture of mineral and other elements.
- The concentration of mineral in the ore should be adequate for its extraction to be worthwhile.
- The structure of mineral present in the ore determines the ease with which it can be extracted. This also determines the cost of the extraction process.
Occurrence of minerals
Minerals occur in:
- Igneous and metamorphic rocks
- Sedimentary rocks
- Weathering and decomposition of rocks
- Alluvial deposits
- Ocean water and ocean bed
In igneous and metamorphic rocks
- Minerals in igneous and metamorphic rocks are found in cracks, faults, and joints of the rocks.
- Minerals in the molten or gaseous states are forced towards the earth’s surface. These molten minerals get deposited in the rock cavities.
- As the minerals rise to the surface of the earth, they cool and solidify.
- Smaller deposits of minerals are known as veins, and larger deposits are known as lodes.
- Tin, copper, zinc, and lead are obtained from veins and loads.
In sedimentary rocks
- Minerals are found in beds or layers in sedimentary rocks.
- Minerals get deposited, accumulated, and concentrated in horizontal layers in sedimentary rocks.
- Coal and iron are concentrated in the layers of sedimentary rocks under immense heat and pressure over a long period of time.
- Gypsum, potash salt, and sodium salt are formed due to evaporation in sedimentary rocks in arid regions.
Weathering and decomposition of rocks
- Minerals are also formed when surface rocks are weathered and decomposed by natural agents such as water and wind.
- Weathering and decomposition of the parent rock remove soluble constituents and leaves behind a residual mass containing ores.
- Bauxite is formed by weathering and decomposition of the parent material.
In alluvial deposits
- A few minerals occur in the sand of alluvial deposits in river valleys and hill bases.
- Such mineral deposits are known as ‘placer deposits’.
- The unique feature of placer deposits is that the minerals do not get corroded by water.
- Gold, silver, tin, and platinum are found in placer deposits.
In ocean water
- Ocean water contains a variety of minerals.
- These minerals are present in the diffused form.
- Thus, the extraction of minerals from ocean water is a costly process.
- Common salt, magnesium, and bromine are extracted from ocean water.
- Manganese nodules are found in the ocean bed.
Mineral Deposits in India
Where are deposits of different minerals found in India?
Minerals in India
- India has rich mineral resources that are distributed unevenly throughout the country.
- The variations in the distribution of mineral resources is the result of differences in the time taken and processes of formation and the geological structure of the minerals.
- Peninsular India is rich in coal, mica and many metallic and non-metallic minerals such as manganese, gold, gypsum, limestone.
- Petroleum reserves are found in the sedimentary rocks on the eastern and western flanks of peninsular India, in Gujarat and Assam.
- Rajasthan has a rich composition of non-ferrous minerals such as gold, bauxite and lead.
- The alluvial plains in the north are devoid of any economically viable mineral deposits.
The economic viability of a reserve
- The concentration of a mineral in the ores, ease of its extraction and potential market nearby makes a mineral economically useful.
- When these three conditions are met at any mineral reserve, it can be turned into a mine to carry out extraction.
Classification of minerals
Minerals can be classified as follows:
- Metallic — Ferrous (for example, iron ore, manganese); non-ferrous (for example, copper, bauxite) and precious minerals (for example, gold, silver)
- Non-metallic – for example, mica, limestone
- Energy minerals — for example, coal, petroleum and natural gas
- Ferrous minerals account for three-fourths of the total volume of metallic minerals extracted in the country.
- To a large extent, metallurgical industries are dependent on ferrous metals.
- India has adequate reserves of ferrous minerals to meet its own demand and export it to other countries.
- India has abundant iron ore reserves that are the backbone of the industrial development of the country.
- Magnetite with 70% iron content is regarded as the finest quality iron ore. It possesses excellent magnetic quality and thus is highly valued in the electrical industry.
- Hematite has 50% to 60% iron content and is highly useful in various industries.
- Limonite contains 60% iron.
- Siderite contains nearly 40% iron.
- Odisha is the largest producer of iron ore followed by Chhattisgarh, Karnataka and Jharkhand.
Iron ore belts in India
There are four major iron ore belts in India:
- Odisha-Jharkhand belt
- Durg-Bastar-Chandrapur belt
- Ballari-Chitradurga-Chikkamagaluru-Tumakuru belt
- Maharashtra-Goa belt
- High grade hematite is found in this belt.
- Badampahar mines in the Mayurbhanj and Kendujhar districts contain iron ore reserves.
- Iron ore is mined in Gua and Noamundi in the Singbhum district of Jharkhand.
- Very high-grade hematite is found in Chhattisgarh and Maharashtra regions.
- Iron ore reserves are situated in the Bailadila range of hills in the Bastar district of Chhattisgarh.
- Altogether there are 14 reserves of high-grade hematite in these hill ranges.
- Due to its good physical properties, iron ore from these reserves is used in steel making.
- It is also exported to Japan and South Korea through Vishakhapatnam port.
- This belt is located in Karnataka.
- Iron ore from the Kudremukh mines located in the Western Ghats of Karnataka is entirely exported.
- The iron ore is transported through pipelines in the form of slurry to the Mangaluru port.
- This belt extends from Goa to the Ratnagiri district of Maharashtra.
- Iron ore found here is not of very superior quality but still is exported through Marmagao port.
- Manganese is used to make steel and ferro-manganese alloy.
- Just 10 kgs of manganese is used to produce 1 tonne of steel.
- Manganese is also used in the manufacture of bleaching powder, paints and insecticides.
- Madhya Pradesh, Maharashtra and Odisha are the leading producers of manganese in the country.
- India’s production of non-ferrous metals is fairly low.
- Copper, bauxite, lead, zinc and gold mined in India are used in metallurgical, engineering and electrical industries.
- India has fairly low copper production.
- Malleability, ductility and being a good conductor makes copper suitable for use in electrical cables, electronics and chemical industries.
- Madhya Pradesh (Balaghat mines), Rajasthan (Khetri mines), and Jharkhand (Singhbhum district) are the leading producers of copper in the country.
- Aluminium is extracted from a clay-like substance called alumina that is present in bauxite.
- Bauxite reserves are the result of the decomposition of rocks containing aluminium silicates.
- Since aluminium is as strong as iron, is light-weight, malleable and a good conductor of heat and electricity, it is widely used in various industries.
- Amarkantak plateau, Maikal hills and the plateau region of the Bilaspur-Katni region are the main reserves of bauxite in India.
- Odisha is the largest producer of bauxite followed by Gujarat, Jharkhand, Chhattisgarh and Maharashtra.
- Panchpatmali deposits in the Koraput district are the important bauxite deposit in Odisha.
- Mica is a non-metallic mineral.
- It is made up of thin layers of plates or leaves.
- The layers can be split into sheets.
- Sheets can be grouped together to form a large sheet of a few centimetres’ thicknesses
- Mica is available in clear, black, yellow, green, red or brown colour.
- Due to its di-electric strength, low power loss factor, insulating properties and resistance to high voltage, it is ideal for use in the electrical industry.
- Mica reserves are found in the northern edge of the Chota Nagpur plateau and Koderma Gaya–Hazaribagh belt of Jharkhand.
- Ajmer in Rajasthan and Nellore mica belt in Andhra Pradesh are also important producers of mica.
Rock minerals – limestone
- Limestones are found in rocks containing calcium carbonates or calcium and magnesium carbonates.
- Limestone is found commonly in sedimentary rocks.
- It is the basic raw material for the cement industry and for the smelting of iron ore in blast furnaces.
- Rajasthan, Madhya Pradesh, Andhra Pradesh, Chhattisgarh are among the few states that produce limestone in the country.
Hazards of mining
Effects on miners
- Miners inhale dust and noxious fumes at work, which make them prone to pulmonary diseases.
- Miners are exposed to constant threats such as inundation, collation of mine roofs, fires and other mining accidents.
Effects on environment
- Water bodies get polluted in mining areas.
- Dumping of waste from mines leads to pollution of streams and rivers. It also causes degradation of land and soil.
- Strict safety measures need to be implemented at mining sites to minimise the harm to workers and to the natural environment.
Why is it necessary to conserve mineral resources?
- Minerals are present in almost everything that is around us.
- Minerals are also present in our bodies and the food that we eat.
- Industries and agriculture are largely dependent on various minerals.
- The amount of minerals available for human use accounts for only 1% of the earth’s crust.
Depleting mineral reserves
- Minerals require millions of years for their formation.
- There is a large difference between the rate at which minerals are formed and the rate at which human beings consume these minerals.
- The gap is so big that the rate of replenishment is very low.
- Thus, mineral resources are finite but non-renewable.
- Rich mineral deposits of our country are valuable short-lived resources.
- With the increasing demand for mineral resources, there is continuous exploitation of ores.
- The cost of extraction of minerals from great depths increases.
- Over exploitation also reduces the quality of the minerals.
Conservation of minerals
- Planned and sustainable efforts are the need of an hour to conserve mineral resources.
- Human beings can conserve minerals by:
- Reducing the wastage of minerals and their wise use.
- Recycling of metals and using scrap
- Adopting technological advancement to use low grades ores at low cost
- Substituting scarce minerals with substances that are available in abundance
India’s Conventional and Non-Conventional Energy Sources
What are India’s conventional energy sources?
- Conventional sources of energy are available in limited quantities in the natural environment.
- These sources of energy take longer for their formation.
- Overuse of these sources of energy leads to their depletion.
India’s conventional energy sources
- Natural Gas
- Electricity — hydro and thermal electricity
- Coal is the most abundantly available fossil fuel in India.
- It meets the major part of the energy requirement of the country.
- It is used for power generation and energy supply in industries and homes.
- Coal is bulky and loses weight through use as it turns into ash.
- Heavy industries and thermal power stations are generally located near coalfields.
Formation of coal
- Coal is formed by the compression of plant material over millions of years.
- The type of coal formed depends on:
- Degree of compression
- Depth at which plant material is buried
- Time of burial
Varieties of coal found in India
- Formed by decaying plants in swamps
- Low carbon content and low heating capacity
- High moisture content
- Low-grade brown coal
- Soft with high moisture content
- Used for generation of electricity
- Found at great depths
- Exposed to the immense heat of the earth’s interior
- Most commonly used for commercial purposes
- Metallurgical coal, a high-grade bituminous coal
- Used for the smelting of iron in blast furnaces
- Best quality of coal
- Very hard with submetallic luster
- High carbon content
Occurrence of coal
- Coal occurs in rock series of two geological ages — Gondwana and Tertiary
- The coal of Gondwana age is a little over 200 million years old. It is mainly metallurgical coal.
- Gondwana coal is found in Damodar Valley in West Bengal.
- Jharkhand, Jharia, Raniganj, and Bokaro are other important coalfields.
- River valleys of Godavari, Mahanadi, Son, and Wardha also contain Gondwana coal deposits.
- Coal of tertiary age is about 55 million years old.
- It occurs in the north-eastern states such as Assam, Arunachal Pradesh, Meghalaya, and Nagaland.
- Petroleum, or mineral oil, is the second most common source of energy in India.
- Petroleum is used as a fuel for heat and lighting, lubricating machines, and raw material for manufacturing industries.
- Petroleum refineries act as a nodal industry for fertiliser, synthetic textile, and chemical industries.
Occurrence of petroleum
- Petroleum, or mineral oil, is found in anticlines and fault traps in the rock formation of the tertiary age.
- Oil is trapped in the crests of regions of upfolds, anticlines, and domes.
- The layer of rock that contains oil is porous limestone or sandstone.
- The porous oil-bearing rock layer is sandwiched between non-porous layers, and thus the oil cannot escape to other layers.
- Petroleum is also found in fault traps between porous and non-porous layers.
- Mumbai High, Gujarat, and Assam are the major oil-producing regions in the country.
- Assam is the oldest oil-producing state in the country. Digboi, Naharkatiya, and Moran-Hugrijan are the important oil fields in Assam.
- Ankeleshwar is the major oil-producing region in Gujarat.
- Natural gas is a clean energy resource.
- It may be found with or without petroleum.
- Natural gas is used as a raw material in the petrochemical industry.
- Natural gas is termed green fuel for its low carbon emission.
- Natural gas reserves are found in Krishna–Godavari basin, Mumbai High, Gulf of Cambay, and Andaman and the Nicobar Islands.
- Hazira-Vijaipur-Jagdishpur cross-country gas pipeline is 1,700 km long. It links Mumbai High and Bassien with fertiliser plants and industrial regions in the northern and western parts of the country.
- Natural gas is abundantly used in power and fertiliser industries.
- The use of CNG (compressed natural gas) is environment-friendly for its low carbon emission and popular for its low cost.
- Electricity is needed for various activities in our daily life.
- Per capita consumption of electricity is the index of development of a country.
- Electricity is generated in two ways.
- Running water is used to drive hydro turbines to generate hydroelectricity.
- The burning of fuels such as coal, natural gas, and petroleum is used to drive turbines to produce thermal energy.
- Fast flowing water is used to turn turbines to generate hydroelectricity.
- Various multipurpose projects producing hydel power in India are Bhakra Nangal, Damodar Valley Corporation, and Kopili Hydel Project.
- Thermal power plants use non-renewable energy sources.
- Electricity is produced by burning coal, natural gas, and petroleum.
- Thermal power plants are located in Bihar, Maharashtra, Uttar Pradesh, and some other states.
What are India’s non-conventional energy sources?
- The two major categories of sources of energy are conventional and non-conventional sources of energy.
- Conventional sources of energy are limited in quantity.
- Non-conventional sources of energy are found in abundance in nature.
- The growing population had increased the demand for energy consumption.
- Increased demand for energy has led to pressure on fossil fuels such as coal, oil, and gas.
- Overuse of fossil fuels and rising oil and gas prices have made uncertain the continuous supply of energy in the future.
- Inflation in the price of oil has adversely affected the national economy.
- The use of non-conventional sources of energy, such as solar, wind, biomass, tidal, and energy from waste material, is the need of the hour.
- India has immense potential to harness energy from sunlight, wind, and biomass.
India’s non-conventional energy sources
- Nuclear or atomic energy
- Solar energy
- Wind power
- Tidal energy
- Geothermal energy
- Nuclear energy is obtained by altering the atomic structure of uranium and thorium.
- Alteration of the atomic structure of these minerals releases heat that is used to generate electric power.
- Uranium and thorium are available in Jharkhand, in Aravalli Hills in Rajasthan, and Monazite sand in Kerala.
- Six nuclear power stations in India are:
- Kakrapar nuclear power station
- Narora nuclear power station
- Kaiga nuclear power station
- Tarapur nuclear power station
- Kalpakkam nuclear power station
- Rawat Bhata nuclear power station
- India being a tropical country, receives enough sunlight throughout the year that it can be trapped to generate electricity.
- Photovoltaic cells are used to convert sunlight into electricity directly.
- Solar power is gaining popularity in rural and remote areas of the country.
- Solar energy will reduce the dependency of rural people on firewood and cow dung for fuel.
- It will also help in environmental conservation.
- India has a huge capacity to produce energy from wind power.
- The largest wind farm cluster is situated in Tamil Nadu and extends from Nagarcoil to Madurai.
- Other places generating wind energy are Andhra Pradesh, Karnataka, Gujarat, Kerala, Maharashtra, and Lakshadweep.
- The plants at Jaisalmer and Nagarcoil make the greatest use of wind energy.
- In rural areas, biogas is generated from the decomposition of organic wastes such as shrubs, farm waste, and animal and human waste.
- The gas yield has higher thermal efficiency than kerosene, dung cake, and charcoal.
- Biogas chambers are easy to set up and can be set up at individual, community, and cooperative levels.
- Biogas plants that use cattle dung are called gobar gas plants.
- Biogas also saves trees from being felled for firewood.
- Biogas plants help farmers in two ways:
- They provide energy.
- The slurry left at the end of the process is rich in nitrogen and phosphorous that make the soil fertile.
- Tides in the ocean are used to generate electricity.
- Flood gates are made across sea and ocean inlets.
- During high tide, the water enters these inlets and is trapped when the flood gates are closed.
- After the high tide, the water from the inlets flows back to the ocean through a pipe that contains a power-generating turbine.
- The Gulf of Khambhat and the Gulf of Kuchchh in Gujarat and the Gangetic delta in the Sunderban regions of West Bengal provide ideal conditions to harness energy from tidal waves.
- Geothermal energy is harnessed from the heat of the interior of the earth.
- Temperature increases from the surface of the earth to its core; the greater the depth, the greater the heat.
- At places with high geothermal gradients, high temperatures are found at shallow depths.
- Groundwater in these areas absorbs heat from the surrounding rocks and becomes hot.
- Hot water rises to the earth’s surface and ejects as a stream.
- The stream drives turbines and generates electricity.
- In India, geothermal energy is produced in Parvati valley near Manikarn in Himachal Pradesh and Puga Valley in Ladakh.
Why is there a need to conserve energy resources?
- Energy is needed for the economic development of the country.
- Energy is needed for agriculture, industries, transport, and domestic uses.
- The energy was needed to implement the economic development plans launched after independence.
- The growth in economic activities has caused an increased demand for energy across the country.
Sustainable energy development
- Due to heavy demand, there is an urgent need to formulate a sustainable path for energy development.
- Two ways to attain sustainable energy are:
- Promotion of energy conservation
- Increased use of renewable energy resources
Energy source in India
- India is regarded as one of the least energy-efficient countries in the world.
- Citizens need to adopt a conservation approach to use limited resources available in the country.
- A few steps citizens can take towards energy conservation are:
- Use of public transport
- Switching off electrical appliances when not in use
- Use of power-saving devices
- Use of non-conventional sources of energy
- All these steps will help to avoid wastage of energy in any form and save it for the future.