Minerals And Energy Resources

Good morning, dear students! I am so happy to see all of you today. Today we are going to learn about something extremely important that touches every single aspect of our lives. We are going to study Chapter 5 from your Geography textbook – Minerals and Energy Resources.

Now, before we begin, let me ask you a question. Think about your morning routine today. What did you use? You brushed your teeth with toothpaste, didn't you? Did you know that the toothpaste you use contains several minerals? Let me tell you how. The cleaning action in toothpaste comes from abrasive minerals like silica, limestone, aluminium oxide, and various phosphate minerals. The fluoride that helps reduce cavities comes from a mineral called fluorite. Most toothpastes are made white using titanium oxide, which comes from minerals called rutile, ilmenite, and anatase. And that little sparkle you sometimes see in toothpaste? That comes from mica! The toothbrush and the tube are made from plastics derived from petroleum, which is another mineral resource. Isn't that wonderful? So the next time you brush your teeth, remember you are using minerals!

Now, let me tell you a story. There is a boy named Haban who comes from a remote village to Guwahati with his father. He sees people getting into strange house-like objects which move along the road. He also sees a "kitchen" dragging a number of houses along with it. He is amazed and asks his father, "Why don't our houses move like the one we saw in Guwahati, Ba?" His father replies, "These are not houses, they are buses and trains. Unlike our houses, these are not made of bricks and stones. Metals like iron and aluminium are used in making these. They do not move on their own. They are driven by an engine which needs energy to work."

This story beautifully introduces us to the world of minerals and energy. You use different things in your daily life made from metal. Can you list a number of items used in your house made of metals? Your answer may include utensils, doors and windows made of aluminium, iron rods used in construction, copper wires for electrical connections, gold ornaments, and so on. Where do these metals come from? They come from minerals found in the earth's crust.

So students, let us understand what minerals are. You have already studied that the earth's crust is made up of different minerals embedded in the rocks. Various metals are extracted from these minerals after proper refinement. Minerals are an indispensable part of our lives. Almost everything we use, from a tiny pin to a towering building or a big ship, all are made from minerals. The railway lines and the tarmac of the roads, our implements and machinery too are made from minerals. Cars, buses, trains, airplanes are manufactured from minerals and run on power resources derived from the earth. Even the food that we eat contains minerals. In all stages of development, human beings have used minerals for their livelihood, decoration, festivities, religious and ceremonial rites.

Now, let me tell you something very interesting. All living things need minerals. Life processes cannot occur without minerals. Although our mineral intake represents only about 0.3 percent of our total intake of nutrients, they are so potent and so important that without them we would not be able to utilise the other 99.7 percent of foodstuffs. Isn't that surprising? Just 0.3 percent of minerals are so essential that without them, our bodies cannot use the food we eat!

Now, what exactly is a mineral? Geologists define mineral as a "homogenous, naturally occurring substance with a definable internal structure." Students, please remember this definition as it is very important. Minerals are found in varied forms in nature, ranging from the hardest diamond to the softest talc. Why are they so varied? This is because different minerals are formed under different physical and chemical conditions.

You have already learnt about rocks. Rocks are combinations of homogenous substances called minerals. Some rocks, for instance limestone, consist of a single mineral only, but majority of the rock consist of several minerals in varying proportions. Although over 2000 minerals have been identified, only a few are abundantly found in most of the rocks.

A particular mineral that will be formed from a certain combination of elements depends upon the physical and chemical conditions under which the material forms. This, in turn, results in a wide range of colours, hardness, crystal forms, lustre and density that a particular mineral possesses. Geologists use these properties to classify the minerals.

Now, let me tell you about the difference between how geographers and geologists study minerals. Geographers study minerals as part of the earth's crust for a better understanding of landforms. The distribution of mineral resources and associated economic activities are of interest to geographers. A geologist, however, is interested in the formation of minerals, their age and physical and chemical composition.

Now, let us learn about the mode of occurrence of minerals. Where are these minerals found? Minerals are usually found in "ores". The term ore is used to describe an accumulation of any mineral mixed with other elements. The mineral content of the ore must be in sufficient concentration to make its extraction commercially viable. The type of formation or structure in which they are found determines the relative ease with which mineral ores may be mined. This also determines the cost of extraction. It is, therefore, important for us to understand the main types of formations in which minerals occur.

Students, minerals generally occur in these forms. Let me explain each one of them.

First, in igneous and metamorphic rocks, minerals may occur in the cracks, crevices, faults or joints. The smaller occurrences are called veins and the larger are called lodes. In most cases, they are formed when minerals in liquid or molten and gaseous forms are forced upward through cavities towards the earth's surface. They cool and solidify as they rise. Major metallic minerals like tin, copper, zinc and lead are obtained from veins and lodes.

Second, in sedimentary rocks, a number of minerals occur in beds or layers. They have been formed as a result of deposition, accumulation and concentration in horizontal strata. Coal and some forms of iron ore have been concentrated as a result of long periods under great heat and pressure. Another group of sedimentary minerals include gypsum, potash salt and sodium salt. These are formed as a result of evaporation, especially in arid regions.

Third, another mode of formation involves the decomposition of surface rocks, and the removal of soluble constituents, leaving a residual mass of weathered material containing ores. Bauxite is formed this way.

Fourth, certain minerals may occur as alluvial deposits in sands of valley floors and the base of hills. These deposits are called 'placer deposits' and generally contain minerals, which are not corroded by water. Gold, silver, tin and platinum are most important among such minerals.

Fifth, the ocean waters contain vast quantities of minerals, but most of these are too widely diffused to be of economic significance. However, common salt, magnesium and bromine are largely derived from ocean waters. The ocean beds, too, are rich in manganese nodules.

Now, let me tell you about an interesting fact related to mining in India. Do you know that most of the minerals in India are nationalised and their extraction is possible only after obtaining due permission from the government? But in most of the tribal areas of the north-east India, minerals are owned by individuals or communities. In Meghalaya, there are large deposits of coal, iron ore, limestone and dolomite. Coal mining in Jowai and Cherapunjee is done by family members in the form of a long narrow tunnel, known as 'Rat hole' mining. The National Green Tribunal has declared such activities illegal and recommended that these should be stopped forthwith. This is because rat-hole mining is very dangerous and harmful to the environment.

Now, let us learn about the classification of minerals. For general and commercial purposes, minerals can be classified into three main categories. First, metallic minerals, which include ferrous minerals (containing iron) like iron ore, manganese, nickel, cobalt, and so on; non-ferrous minerals like copper, lead, tin, bauxite; and precious metals like gold, silver, and platinum. Second, non-metallic minerals like mica, salt, potash, sulphur, granite, limestone, marble, sandstone. Third, energy minerals like coal, petroleum, and natural gas.

Now, let me tell you about the distribution of minerals in India. India is fortunate to have fairly rich and varied mineral resources. However, these are unevenly distributed. Broadly speaking, peninsular rocks contain most of the reserves of coal, metallic minerals, mica and many other non-metallic minerals. Sedimentary rocks on the western and eastern flanks of the peninsula, in Gujarat and Assam have most of the petroleum deposits. Rajasthan with the rock systems of the peninsula, has reserves of many non-ferrous minerals. The vast alluvial plains of north India are almost devoid of economic minerals. These variations exist largely because of the differences in the geological structure, processes and time involved in the formation of minerals.

Now, let us study the distribution of a few major minerals in India. Always remember that the concentration of mineral in the ore, the ease of extraction and closeness to the market play an important role in affecting the economic viability of a reserve. Thus, to meet the demand, a choice has to be made between a number of possible options. When this is done, a mineral 'deposit' or 'reserve' turns into a mine.

Let us start with ferrous minerals. Ferrous minerals account for about three-fourths of the total value of the production of metallic minerals. They provide a strong base for the development of metallurgical industries. India exports substantial quantities of ferrous minerals after meeting her internal demands.

The most important ferrous mineral is iron ore. Iron ore is the basic mineral and the backbone of industrial development. India is endowed with fairly abundant resources of iron ore. India is rich in good quality iron ores. Magnetite is the finest iron ore with a very high content of iron up to 70 percent. It has excellent magnetic qualities, especially valuable in the electrical industry. Hematite ore is the most important industrial iron ore in terms of the quantity used, but has a slightly lower iron content than magnetite, about 50 to 60 percent. In 2018-19, almost entire production of iron ore (97 percent) accrued from Odisha, Chhattisgarh, Karnataka and Jharkhand. The remaining production (3 percent) was from other states.

Now, let me tell you an interesting fact. Kudre in Kannada means horse. The highest peak in the western ghats of Karnataka resembles the face of a horse. The Bailadila hills look like the hump of an ox, and hence its name.

The major iron ore belts in India are as follows.

The Odisha-Jharkhand belt: In Odisha, high grade hematite ore is found in Badampahar mines in the Mayurbhanj and Kendujhar districts. In the adjoining Singbhum district of Jharkhand, hematite iron ore is mined in Gua and Noamundi.

The Durg-Bastar-Chandrapur belt lies in Chhattisgarh and Maharashtra. Very high grade hematites are found in the famous Bailadila range of hills in the Bastar district of Chhattisgarh. The range of hills comprise of 14 deposits of super high grade hematite iron ore. It has the best physical properties needed for steel making. Iron ore from these mines is exported to Japan and South Korea via Vishakhapatnam port.

The Ballari-Chitradurga-Chikkamagaluru-Tumakuru belt in Karnataka has large reserves of iron ore. The Kudremukh mines located in the Western Ghats of Karnataka are a 100 percent export unit. Kudremukh deposits are known to be one of the largest in the world. The ore is transported as slurry through a pipeline to a port near Mangaluru.

The Maharashtra-Goa belt includes the state of Goa and Ratnagiri district of Maharashtra. Though the ores are not of very high quality, yet they are efficiently exploited. Iron ore is exported through Marmagao port.

Now, let us learn about manganese. Manganese is mainly used in the manufacturing of steel and ferro-manganese alloy. Nearly 10 kg of manganese is required to manufacture one tonne of steel. It is also used in manufacturing bleaching powder, insecticides and paints.

Now, let us move on to non-ferrous minerals. India's reserves and production of non-ferrous minerals is not very satisfactory. However, these minerals, which include copper, bauxite, lead, zinc and gold, play a vital role in a number of metallurgical, engineering and electrical industries.

Let us study copper first. India is critically deficient in the reserve and production of copper. Being malleable, ductile and a good conductor, copper is mainly used in electrical cables, electronics and chemical industries. The Balaghat mines in Madhya Pradesh, Khetri mines in Rajasthan and Singhbhum district of Jharkhand are leading producers of copper.

Now, let us learn about bauxite. Though several ores contain aluminium, it is from bauxite, a clay-like substance that alumina and later aluminium is obtained. Bauxite deposits are formed by the decomposition of a wide variety of rocks rich in aluminium silicates.

Aluminium is an important metal because it combines the strength of metals such as iron, with extreme lightness and also with good conductivity and great malleability.

India's bauxite deposits are mainly found in the Amarkantak plateau, Maikal hills and the plateau region of Bilaspur-Katni.

Odisha was the largest bauxite producing state in India in 2018-19. Panchpatmali deposits in Koraput district are the most important bauxite deposits in the state.

Now, let me tell you an interesting historical fact. After the discovery of aluminium, Emperor Napoleon III wore buttons and hooks on his clothes made of aluminium and served food to his more illustrious guests in aluminium utensils, while the less honourable ones were served in gold and silver utensils. Thirty years after this incident, aluminium bowls were most common with the beggars in Paris. This shows how aluminium, which was once as precious as gold, became common over time due to technological advancements.

Now, let us learn about rock minerals. Limestone is found in association with rocks composed of calcium carbonates or calcium and magnesium carbonates. It is found in sedimentary rocks of most geological formations. Limestone is the basic raw material for the cement industry and essential for smelting iron ore in the blast furnace.

Now, let us learn about non-metallic minerals. Mica is a mineral made up of a series of plates or leaves. It splits easily into thin sheets. These sheets can be so thin that a thousand can be layered into a mica sheet of a few centimeters high. Mica can be clear, black, green, red, yellow or brown. Due to its excellent di-electric strength, low power loss factor, insulating properties and resistance to high voltage, mica is one of the most indispensable minerals used in electric and electronic industries.

Mica deposits are found in the northern edge of the Chota Nagpur plateau. Koderma, Gaya and Hazaribagh belt of Jharkhand is the leading producer. In Rajasthan, the major mica producing area is around Ajmer. Nellore mica belt of Andhra Pradesh is also an important producer in the country.

Now, let me ask you a question. Why is Chota Nagpur a storehouse of minerals? This is because Chota Nagpur plateau is made of ancient crystalline rocks that contain rich deposits of minerals like mica, iron ore, copper, coal, and so on. The geological processes that formed this plateau over millions of years resulted in the concentration of these valuable minerals.

Now, let us learn about the hazards of mining. Have you ever wondered about the efforts the miners make in making life comfortable for you? What are the impacts of mining on the health of the miners and the environment?

The dust and noxious fumes inhaled by miners make them vulnerable to pulmonary diseases. The risk of collapsing mine roofs, inundation and fires in coal mines are a constant threat to miners.

The water sources in the region get contaminated due to mining. Dumping of waste and slurry leads to degradation of land, soil, and increase in stream and river pollution.

Stricter safety regulations and implementation of environmental laws are essential to prevent mining from becoming a "killer industry".

Now, let us learn about the conservation of minerals. We all appreciate the strong dependence of industry and agriculture upon mineral deposits and the substances manufactured from them. The total volume of workable mineral deposits is an insignificant fraction, that is, one percent of the earth's crust. We are rapidly consuming mineral resources that required millions of years to be created and concentrated. The geological processes of mineral formation are so slow that the rates of replenishment are infinitely small in comparison to the present rates of consumption. Mineral resources are, therefore, finite and non-renewable. Rich mineral deposits are our country's extremely valuable but short-lived possessions. Continued extraction of ores leads to increasing costs as mineral extraction comes from greater depths along with decrease in quality.

A concerted effort has to be made in order to use our mineral resources in a planned and sustainable manner. Improved technologies need to be constantly evolved to allow use of low grade ores at low costs. Recycling of metals, using scrap metals and other substitutes are steps in conserving our mineral resources for the future.

Now, let us learn about energy resources. Energy is required for all activities. It is needed to cook, to provide light and heat, to propel vehicles and to drive machinery in industries.

Energy can be generated from fuel minerals like coal, petroleum, natural gas, uranium and from electricity. Energy resources can be classified as conventional and non-conventional sources. Conventional sources include: firewood, cattle dung cake, coal, petroleum, natural gas and electricity (both hydel and thermal). Non-conventional sources include solar, wind, tidal, geothermal, biogas and atomic energy. Firewood and cattle dung cake are most common in rural India.

According to one estimate, more than 70 percent energy requirement in rural households is met by these two; continuation of these is increasingly becoming difficult due to decreasing forest area. Moreover, using dung cake too is being discouraged because it consumes most valuable manure which could be used in agriculture.

Now, let us study conventional sources of energy in detail.

First, let us learn about coal. In India, coal is the most abundantly available fossil fuel. It provides a substantial part of the nation's energy needs. It is used for power generation, to supply energy to industry as well as for domestic needs. India is highly dependent on coal for meeting its commercial energy requirements.

As you are already aware, coal is formed due to the compression of plant material over millions of years. Coal, therefore, is found in a variety of forms depending on the degrees of compression and the depth and time of burial. Decaying plants in swamps produce peat, which has a low carbon and high moisture contents and low heating capacity. Lignite is a low grade brown coal, which is soft with high moisture content. The principal lignite reserves are in Neyveli in Tamil Nadu and are used for generation of electricity. Coal that has been buried deep and subjected to increased temperatures is bituminous coal. It is the most popular coal in commercial use. Metallurgical coal is high grade bituminous coal which has a special value for smelting iron in blast furnaces. Anthracite is the highest quality hard coal.

In India, coal occurs in rock series of two main geological ages, namely Gondwana, a little over 200 million years in age, and in tertiary deposits which are only about 55 million years old. The major resources of Gondwana coal, which are metallurgical coal, are located in Damodar valley (West Bengal-Jharkhand). Jharia, Raniganj, Bokaro are important coalfields. The Godavari, Mahanadi, Son and Wardha valleys also contain coal deposits.

Tertiary coals occur in the north eastern states of Meghalaya, Assam, Arunachal Pradesh and Nagaland.

Remember, coal is a bulky material, which loses weight on use as it is reduced to ash. Hence, heavy industries and thermal power stations are located on or near the coalfields.

Now, let us learn about petroleum. Petroleum or mineral oil is the next major energy source in India after coal. It provides fuel for heat and lighting, lubricants for machinery and raw materials for a number of manufacturing industries. Petroleum refineries act as a "nodal industry" for synthetic textile, fertiliser and numerous chemical industries.

Most of the petroleum occurrences in India are associated with anticlines and fault traps in the rock formations of the tertiary age. In regions of folding, anticlines or domes, it occurs where oil is trapped in the crest of the upfold. The oil bearing layer is a porous limestone or sandstone through which oil may flow. The oil is prevented from rising or sinking by intervening non-porous layers.

Petroleum is also found in fault traps between porous and non-porous rocks. Gas, being lighter, usually occurs above the oil.

Mumbai High, Gujarat and Assam are major petroleum production areas in India. Ankaleshwar is the most important field of Gujarat. Assam is the oldest oil producing state of India. Digboi, Naharkatiya and Moran-Hugrijan are the important oil fields in the state.

Now, let us learn about 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. It is used as fuel in power sector to generate electricity, for heating purpose in industries, as raw material in chemical, petrochemical and fertilizer industries, as transport fuel and as cooking fuel. With the expansion of gas infrastructure and local city gas distribution networks, natural gas is also emerging as a preferred transport fuel (CNG) and cooking fuel (PNG) at homes.

India's major gas reserves are found in the Mumbai High and allied fields along the west coast, which are supplemented by finds in the Cambay basin. Along the East Coast, new reserves of natural gas have been discovered in the Krishna-Godavari basin.

The first 1,700 km long Hazira-Vijaipur-Jagdishpur cross country gas pipeline, constructed by GAIL (India), linked Mumbai High and Bassein gas fields with various fertilizer, power and industrial complexes in western and northern India. This artery provided impetus to Indian gas market development. Overall, India's gas infrastructure has expanded over ten times from 1,700 km to 18,500 km of cross-country pipelines and is expected to soon reach over 34,000 km as Gas Grid by linking all gas sources and consuming markets across the country including North Eastern states.

Now, let us learn about electricity. Electricity has such a wide range of applications in today's world that its per capita consumption is considered as an index of development. Electricity is generated mainly in two ways: by running water which drives hydro turbines to generate hydro electricity; and by burning other fuels such as coal, petroleum and natural gas to drive turbines to produce thermal power. Once generated, the electricity is exactly the same.

Hydro electricity is generated by fast flowing water, which is a renewable resource. India has a number of multi-purpose projects like the Bhakra Nangal, Damodar Valley Corporation, the Kopili Hydel Project, etc. producing hydroelectric power.

Thermal electricity is generated by using coal, petroleum and natural gas. The thermal power stations use non-renewable fossil fuels for generating electricity.

Now, let us learn about non-conventional sources of energy. The growing consumption of energy has resulted in the country becoming increasingly dependent on fossil fuels such as coal, oil and gas. Rising prices of oil and gas and their potential shortages have raised uncertainties about the security of energy supply in future, which in turn has serious repercussions on the growth of the national economy. Moreover, increasing use of fossil fuels also causes serious environmental problems. Hence, there is a pressing need to use renewable energy sources like solar energy, wind, tide, biomass and energy from waste material. These are called non-conventional energy sources.

India is blessed with an abundance of sunlight, water, wind and biomass. It has the largest programmes for the development of these renewable energy resources.

Let us learn about nuclear or atomic energy. It is obtained by altering the structure of atoms. When such an alteration is made, much energy is released in the form of heat and this is used to generate electric power. Uranium and Thorium, which are available in Jharkhand and the Aravalli ranges of Rajasthan, are used for generating atomic or nuclear power. The Monazite sands of Kerala is also rich in Thorium.

Now, let us learn about solar energy. India is a tropical country. It has enormous possibilities of tapping solar energy. Photovoltaic technology converts sunlight directly into electricity. Solar energy is fast becoming popular in rural and remote areas. Some big solar power plants are being established in different parts of India which will minimise the dependence of rural households on firewood and dung cakes, which in turn will contribute to environmental conservation and adequate supply of manure in agriculture.

Now, let us learn about wind power. India has great potential of wind power. The largest wind farm cluster is located in Tamil Nadu from Nagarcoil to Madurai. Apart from these, Andhra Pradesh, Karnataka, Gujarat, Kerala, Maharashtra and Lakshadweep have important wind farms. Nagarcoil and Jaisalmer are well known for effective use of wind energy in the country.

Now, let us learn about biogas. Shrubs, farm waste, animal and human waste are used to produce biogas for domestic consumption in rural areas. Decomposition of organic matter yields gas, which has higher thermal efficiency in comparison to kerosene, dung cake and charcoal. Biogas plants are set up at municipal, cooperative and individual levels. The plants using cattle dung are known as 'Gobar gas plants' in rural India. These provide twin benefits to the farmer in the form of energy and improved quality of manure. Biogas is by far the most efficient use of cattle dung. It improves the quality of manure and also prevents the loss of trees and manure due to burning of fuel wood and cow dung cakes.

Now, let us learn about tidal energy. Oceanic tides can be used to generate electricity. Floodgate dams are built across inlets. During high tide, water flows into the inlet and gets trapped when the gate is closed. After the tide falls outside the flood gate, the water retained by the floodgate flows back to the sea via a pipe that carries it through a power-generating turbine.

In India, the Gulf of Khambhat, the Gulf of Kuchchh in Gujarat on the western coast and Gangetic delta in Sunderban regions of West Bengal provide ideal conditions for utilising tidal energy.

Now, let us learn about geothermal energy. Geothermal energy refers to the heat and electricity produced by using the heat from the interior of the Earth. Geothermal energy exists because the Earth grows progressively hotter with increasing depth. Where the geothermal gradient is high, high temperatures are found at shallow depths. Groundwater in such areas absorbs heat from the rocks and becomes hot. It is so hot that when it rises to the earth's surface, it turns into steam. This steam is used to drive turbines and generate electricity.

There are several hundred hot springs in India, which could be used to generate electricity. Two experimental projects have been set up in India to harness geothermal energy. One is located in the Parvati valley near Manikaran in Himachal Pradesh and the other is located in the Puga Valley, Ladakh.

Now, let us learn about the conservation of energy resources. Energy is a basic requirement for economic development. Every sector of the national economy – agriculture, industry, transport, commercial and domestic – needs inputs of energy. The economic development plans implemented since Independence necessarily required increasing amounts of energy to remain operational. As a result, consumption of energy in all forms has been steadily rising all over the country.

In this background, there is an urgent need to develop a sustainable path of energy development. Promotion of energy conservation and increased use of renewable energy sources are the twin planks of sustainable energy.

India is presently one of the least energy efficient countries in the world. We have to adopt a cautious approach for the judicious use of our limited energy resources. For example, as concerned citizens we can do our bit by using public transport systems instead of individual vehicles; switching off electricity when not in use, using power-saving devices and using non-conventional sources of energy. After all, "energy saved is energy produced".

Now, students, let me solve the exercises for you. Let us start with the multiple choice questions.

Question 1: Which one of the following minerals is formed by decomposition of rocks, leaving a residual mass of weathered material? The answer is (b) bauxite. This is because bauxite is formed by the decomposition of surface rocks and the removal of soluble constituents, leaving a residual mass of weathered material.

Question 2: Koderma, in Jharkhand is the leading producer of which one of the following minerals? The answer is (b) mica. Koderma, Gaya and Hazaribagh belt of Jharkhand is the leading producer of mica.

Question 3: Minerals are deposited and accumulated in the stratas of which of the following rocks? The answer is (a) sedimentary rocks. In sedimentary rocks, minerals occur in beds or layers and have been formed as a result of deposition, accumulation and concentration in horizontal strata.

Question 4: Which one of the following minerals is contained in the Monazite sand? The answer is (c) thorium. The Monazite sands of Kerala are rich in Thorium.

Now, let us move on to the short answer questions.

Question (i)(a): Distinguish between ferrous and non-ferrous minerals. Ferrous minerals are those that contain iron, such as iron ore and manganese. They provide a strong base for the development of metallurgical industries. Non-ferrous minerals do not contain iron, such as copper, bauxite, lead, and zinc. They play a vital role in a number of metallurgical, engineering and electrical industries.

Question (i)(b): Distinguish between conventional and non-conventional sources of energy. Conventional sources of energy are those that have been in use for a long time and include firewood, cattle dung cake, coal, petroleum, natural gas and electricity. They are mostly non-renewable and cause pollution. Non-conventional sources of energy are those that are renewable and environment-friendly, such as solar energy, wind energy, tidal energy, geothermal energy, biogas and atomic energy.

Question (ii): What is a mineral? A mineral is a homogenous, naturally occurring substance with a definable internal structure. It is found in varied forms in nature and is formed under specific physical and chemical conditions. Minerals are the building blocks of rocks and are essential for various industrial and economic activities.

Question (iii): How are minerals formed in igneous and metamorphic rocks? In igneous and metamorphic rocks, minerals may occur in the cracks, crevices, faults or joints. The smaller occurrences are called veins and the larger are called lodes. In most cases, they are formed when minerals in liquid or molten and gaseous forms are forced upward through cavities towards the earth's surface. They cool and solidify as they rise. Major metallic minerals like tin, copper, zinc and lead are obtained from veins and lodes.

Question (iv): Why do we need to conserve mineral resources? We need to conserve mineral resources because they are finite and non-renewable. The geological processes of mineral formation are so slow that the rates of replenishment are infinitely small in comparison to the present rates of consumption. We are rapidly consuming mineral resources that required millions of years to be created and concentrated. Continued extraction of ores leads to increasing costs as mineral extraction comes from greater depths along with decrease in quality. Therefore, we need to use our mineral resources in a planned and sustainable manner.

Now, let us move on to the long answer questions.

Question (i): Describe the distribution of coal in India.

In India, coal occurs in rock series of two main geological ages. The first is the Gondwana coal, which is a little over 200 million years in age. The major resources of Gondwana coal, which are metallurgical coal, are located in the Damodar valley in West Bengal and Jharkhand. Jharia, Raniganj and Bokaro are important coalfields in this region. The Godavari, Mahanadi, Son and Wardha valleys also contain coal deposits.

The second is the tertiary deposits, which are only about 55 million years old. Tertiary coals occur in the north eastern states of Meghalaya, Assam, Arunachal Pradesh and Nagaland.

Coal is a bulky material that loses weight on use as it is reduced to ash. Hence, heavy industries and thermal power stations are located on or near the coalfields to reduce transportation costs.

Question (ii): Why do you think that solar energy has a bright future in India?

Solar energy has a bright future in India for several reasons. First, India is a tropical country that receives abundant sunlight throughout the year. This makes it ideal for harnessing solar energy. Second, the photovoltaic technology converts sunlight directly into electricity, which is clean and renewable. Third, solar energy is fast becoming popular in rural and remote areas where grid electricity is not available. Fourth, some big solar power plants are being established in different parts of India, which will minimise the dependence of rural households on firewood and dung cakes. This will contribute to environmental conservation and ensure adequate supply of manure in agriculture. Fifth, the government of India has launched various schemes and programs to promote solar energy, such as the National Solar Mission. Sixth, solar energy is a non-conventional source of energy that does not cause pollution and is sustainable in the long run. Therefore, solar energy has a bright future in India.

Now, students, let me also tell you about the activity related to cross country natural gas pipelines. The activity asks you to collect information about cross country natural gas pipelines laid by GAIL (India) under "One Nation One Grid". As I mentioned earlier, the first 1,700 km long Hazira-Vijaipur-Jagdishpur (HVJ) cross country gas pipeline, constructed by GAIL (India), linked Mumbai High and Bassein gas fields with various fertilizer, power and industrial complexes in western and northern India. Overall, India's gas infrastructure has expanded over ten times from 1,700 km to 18,500 km of cross-country pipelines and is expected to soon reach over 34,000 km as Gas Grid by linking all gas sources and consuming markets across the country including North Eastern states.

Now, there is also an activity about river valley projects and dams. Some river valley projects in India include the Bhakra Nangal Project on the Satluj river, the Damodar Valley Corporation on the Damodar river, the Hirakud Project on the Mahanadi river, the Nagarjuna Sagar Project on the Krishna river, and the Kopili Hydel Project on the Kopili river.

Now, let me tell you about the nuclear power stations in India. There are several nuclear power stations in India, including Tarapur in Maharashtra, Kakrapara in Gujarat, Kalpakkam in Tamil Nadu, Narora in Uttar Pradesh, Kapund in Karnataka, and Kaiga in Karnataka.

Now, students, let me also tell you about the crossword activity. Let me fill in the answers for you.

Across: 1. A ferrous mineral - MANGANESE (9 letters) 2. Raw material for cement industry - LIMESTONE (9 letters) 3. Finest iron ore with magnetic properties - MAGNETITE (9 letters) 4. Highest quality hard coal - ANTHRACITE (10 letters) 5. Aluminium is obtained from this ore - BAUXITE (7 letters) 6. Khetri mines are famous for this mineral - COPPER (6 letters) 7. Formed due to evaporation - SALTS (6 letters) or more specifically POTASH or SODA

Down: 1. Found in placer deposit - GOLD (4 letters) 2. Iron ore mined in Bailadila - HEMATITE (8 letters) 3. Indispensable for electrical industry - MICA (4 letters) 4. Geological Age of coal found in north east India - TERTIARY (8 letters) 5. Formed in veins and lODES - ORE (3 letters)

Now, students, let me give you a quick recap of what we have learned today.

We started with the story of Haban and learned that minerals are essential for our daily lives. We learned that minerals are homogenous, naturally occurring substances with a definable internal structure. We studied the mode of occurrence of minerals, which includes occurrence in igneous and metamorphic rocks in veins and lodes, in sedimentary rocks in beds or layers, as residual deposits, as placer deposits, and in ocean waters.

We learned that minerals are classified into metallic minerals (ferrous, non-ferrous, and precious), non-metallic minerals, and energy minerals.

We studied the distribution of major minerals in India. We learned about ferrous minerals like iron ore and manganese. The major iron ore belts in India are the Odisha-Jharkhand belt, the Durg-Bastar-Chandrapur belt, the Ballari-Chitradurga-Chikkamagaluru-Tumakuru belt, and the Maharashtra-Goa belt.

We learned about non-ferrous minerals like copper and bauxite. Copper is produced in Balaghat in Madhya Pradesh, Khetri in Rajasthan, and Singhbhum in Jharkhand. Bauxite is mainly found in Odisha, Amarkantak plateau, and Bilaspur-Katni region.

We learned about non-metallic minerals like mica and limestone. Mica is mainly produced in Koderma-Gaya-Hazaribagh belt of Jharkhand, Ajmer in Rajasthan, and Nellore in Andhra Pradesh.

We learned about the hazards of mining and the need for conservation of minerals. We understood that minerals are finite and non-renewable, and we need to use them sustainably.

Then we moved on to energy resources. We learned about conventional sources like coal, petroleum, natural gas, and electricity. Coal is mainly found in Gondwana rocks in the Damodar valley and tertiary rocks in the north-eastern states. Petroleum is found in Mumbai High, Gujarat, and Assam. Natural gas is found along the west and east coasts.

We learned about non-conventional sources of energy like nuclear energy, solar energy, wind energy, biogas, tidal energy, and geothermal energy. Each of these has great potential in India.

Finally, we learned about the conservation of energy resources and the need to use energy wisely.

Students, I hope this lesson has helped you understand the chapter thoroughly. Remember, minerals and energy resources are very important for our development, but we must use them wisely and conserve them for future generations. Thank you for your attention, and I will see you in the next class!