Mineral and Power Resources | NCERT Standard 8 | Social Science

Minerals : Rocks on earth have several materials called minerals mixed in them. These minerals are scattered throughout the earth’s rocky crust. A naturally occurring substance that has a definite chemical composition is a  mineral. Minerals are not evenly distributed over space. They are concentrated in a particular area or rock formations. Minerals are formed in different types of geological environments, under varying conditions. They are created by natural processes without any human interference. They can be identified on the basis of their physical properties such as colour, density, hardness and chemical property such as solubility. The salt in our food and graphite in your pencil are also minerals.

Ores : Rocks from which minerals are mined are known as ores. Although more than 2,800 types of minerals have been identified, only about 100 are considered ore minerals. Thus one can easily notice that all minerals are rocks but all rocks are not minerals.

Metallic and Non-metallic minerals : The metallic minerals contain metal in raw form. Metals are hard substances that conduct heat and electricity and have a characteristic lustre or shine. Iron ore, bauxite, manganese ore are some examples. Metallic minerals may be ferrous or non-ferrous.  Ferrous minerals like iron ore, manganese and chromites contain iron. A non-ferrous mineral does not contain iron but may contain some other metal such as gold, silver, copper or lead.The non-metallic minerals do not contain metals. Limestone, mica and gypsum are examples of such minerals. The mineral fuels like coal and petroleum are also non-metallic minerals.

Extraction of Minerals : Minerals can be extracted by mining, drilling or quarrying. The process of taking out minerals from rocks buried under the earth’s surface is called mining. Minerals that lie at shallow depths are taken out by removing the surface layer; this is known as open-cast mining. Deep bores, called shafts, have to be made to reach mineral deposits that lie at great depths. This is called  shaft mining. Petroleum and natural gas occur far below the earth’s surface. Deep wells are bored to take them out, this is called  drilling. Minerals that lie near the surface are simply dug out, by the process known as quarrying.

Distribution of Minerals : Minerals occur in different types of rocks. Some are found in igneous rocks, some in metamorphic rocks while others occur in sedimentary rocks. Generally, metallic minerals are found in igneous and metamorphic rock formations that form large plateaus. Sedimentary rock formations of plains and young fold mountains contain non-metallic minerals like limestone. Limestone deposits of Caucasus region of France, manganese deposits of Georgia and Ukraine and phosphate beds of Algeria are some examples. Mineral fuels such as coal and petroleum are also found in the sedimentary strata.

Iron in India : India has deposits of high grade iron ore. The mineral is found mainly in Jharkhand, Orissa, Chhattisgarh, Madhya Pradesh, Goa, Maharashtra and Karnataka.
Bauxite in India : Major bauxite producing areas are Jharkhand, Orissa, Chhattisgarh, Madhya Pradesh, Gujarat, Maharashtra and Tamil Nadu.

Mica in India : Mica  deposits mainly occur in Jharkhand, Bihar, Andhra Pradesh and Rajasthan. India is the largest producer and exporter of mica in the world.

Copper in India : It is mainly produced in Rajasthan,  Madhya Pradesh, Jharkhand, Karnataka and Andhra Pradesh.

Manganese in India : India’s manganese deposits lie in Maharashtra, Madhya Pradesh, Chhattisgarh, Orissa, Karnataka and Andhra Pradesh.

Limestone in India : Major limestone producing states in India are Bihar, Jharkhand, Orissa, Madhya Pradesh, Chhattisgarh, Rajasthan, Gujarat and Tamil Nadu.

Gold in India : Kolar in Karnataka has deposits of gold in India. These mines are among the deepest in the world which makes mining of this ore a very expensive process. So currently mining is suspended here.

Power resources
Power resources may be broadly categorised as conventional and non-conventional resources. Conventional sources of energy are those which have been in common use for a long time. Firewood and fossil fuels are the two main conventional energy sources. Firewood is widely used for cooking and heating. In our country more than fifty per cent of the energy used by villagers comes from fire wood. Remains of plants and animals which were buried under the earth for millions of years got converted by the heat and pressure into fossil fuels. Fossil fuel such as coal, petroleum and natural gas are the main sources of conventional energy. The reserves of these minerals are limited. The rate at which the growing world population is consuming them is far greater than the rate of their formation. So, these are likely to be exhausted soon.

Coal : This is the most abundantly found fossil fuel. It is used as a domestic fuel, in industries such as iron and steel, steam engines and to generate electricity. Electricity from coal is called  thermal power.  The coal which we are using today was formed millions of years ago when giant ferns and swamps got buried under the layers of earth. Coal is therefore referred to as Buried Sunshine.

Petroleum : The petrol that keeps your car running as well as the oil that keeps your cycle from squeaking, both began as a thick black liquid called Petroleum. It is found
between the layers of rocks and is drilled from oil fields located in off-shore and coastal areas. This is then sent to refineries which process the crude oil and produce
a variety of products like diesel, petrol, kerosene, wax, plastics and lubricants. Petroleum and its derivatives are called  Black Gold as they are very valuable.
The chief petroleum producing countries are Iran, Iraq, Saudi Arabia and Qatar. The leading producers in India are Digboi in Assam, Bombay High in Mumbai and the deltas of Krishna and Godavari rivers.

Natural Gas : Natural gas is found with petroleum deposits and is released when crude oil is brought to the surface. It can be used as a domestic and industrial fuel. In India Jaisalmer, Krishna Godavari delta, Tripura and some areas off shore in Mumbai have natural gas resources.

Hydel Power : Rain water or river water stored in dams is made to fall from heights. The falling water flows through pipes inside the dam over turbine blades placed at the bottom of the dam. The moving blades then turn the generator to produce electricity. This is called hydro electricity. The water discharged after the generation of electricity is used for irrigation. One fourth of the world’s electricity is produced by hydel power. Compressed natural gas (CNG) is a popular ecofriendly automobile fuel as it causes less pollution than petroleum and diesel. Norway was the first country in the world to devlop hydroelectricity. Some important hydel power stations in India are Bhakra Nangal, Gandhi Sagar, Nagarjunsagar and Damodar valley projects.

Non-conventional sources : The increasing use of fossil fuels is leading to its shortage. It is estimated that if the present rate of consumption continues, the reserves of these fuel will get exhausted. Moreover, their use also causes environmental pollution. Therefore, there is need for using non-conventional sources such as solar energy, wind energy, tidal energy which are renewable.

Solar energy : Sun’s heat and light energy can be felt by us every day. The technology of utilising solar energy benefits a lot of tropical countries that are blessed with abundant sun shine.

Wind Energy :  Wind is an inexhaustible source of energy. In modern time wind mills, the high speed winds rotate the wind mill which is connected to a generator to produce electricity. Wind farms having clusters of such wind mills are located in coastal regions and in mountain passes where strong and steady winds blow.

Nuclear Power : Nuclear power is obtained from energy stored in the nuclei of atoms of naturally occurring radio active elements like uranium and thorium. These fuels undergo nuclear fission in nuclear reactors and emit power. The greatest producers of nuclear power are USA and Europe. In India Rajasthan and Jharkhand have large deposits of Uranium. Thorium is found in large quantities in the Monozite sands of Kerala.

Geothermal Energy : Heat energy obtained from the earth is called  geothermal energy. The temperature in the interior of the earth rises steadily as we go deeper. Some times this heat energy may surface itself in the form of hot springs. This heat energy can be used to generate power. Geothermal energy in the form of hot springs has been used for cooking, heating and bathing for several years. In India, geothermal plants are located in Manikaran in Himachal Pradesh and Puga Valley in Ladakh.

Tidal Energy : Energy generated from tides is called tidal energy. Tidal energy can be harnessed by building dams at narrow openings of the sea. During high tide the energy of the tides is used to turn the turbine installed in the dam to produce electricity. Russia, France and the Gulf of Kachchh in India have huge tidal mill farms.

Biogas : Organic waste such as dead plant and animal material, animal dung and kitchen waste can be converted into a gaseous fuel called biogas. The organic waste is decomposed by bacteria in biogas digesters to emit biogas which is essentially a mixture of methane and carbon dioxide. Biogas is an excellent fuel for cooking and lighting and produces huge amount of organic manure each year.

Based on Resource and Develpoment Chapter 3 : Mineral and Power Resources http://ncert.nic.in/NCERTS/textbook/textbook.htm?hess4=3-6