Class 8 Social Science Notes Chapter 3 (Mineral and Power Resources) – Resource and Development (Geography) Book

Alright class, let's focus on Chapter 3: Mineral and Power Resources. This is a crucial chapter, not just for your class exams but also for various government competitive exams where Geography plays a significant role. Pay close attention to the definitions, classifications, distributions, and conservation aspects.

Chapter 3: Mineral and Power Resources - Detailed Notes for Exam Preparation

Part 1: Minerals

1. What is a Mineral?

   • A naturally occurring substance that has a definite chemical composition.
   • They are not evenly distributed over space; concentrated in particular areas or rock formations.
   • Formed in different geological environments, under varying conditions, through natural processes without human interference.
   • Identified based on physical properties (colour, density, hardness) and chemical properties (solubility).

2. Types of Minerals:

   • Minerals are broadly classified into Metallic and Non-metallic minerals.

   • A. Metallic Minerals:

     • Contain metal in raw form.
     • Metals are hard substances, conduct heat and electricity, and have lustre or shine.
     • Examples: Iron ore, Bauxite, Manganese ore, Gold, Silver, Copper.
     • Sub-types of Metallic Minerals:
       • i. Ferrous Minerals: Contain iron. Examples: Iron ore, Manganese, Chromites.
       • ii. Non-ferrous Minerals: Do not contain iron but may contain other metals. Examples: Gold, Silver, Copper, Lead, Bauxite (Aluminium ore).

   • B. Non-metallic Minerals:

     • Do not contain metals.
     • Examples: Limestone, Mica, Gypsum, Coal, Petroleum, Salt, Potash, Sulphur.
     • Mineral fuels like Coal and Petroleum are also non-metallic minerals.

3. Extraction of Minerals:

   • The process of taking out minerals from rocks buried under the earth's surface is called Mining.
   • Minerals near the surface are extracted by Open-cast Mining (removing the surface layer).
   • Deep bores, called Shafts, are made to reach mineral deposits at great depths. This is Shaft Mining.
   • Drilling: Deep wells are bored to take out petroleum and natural gas.
   • Quarrying: Minerals lying very near the surface are simply dug out by this process.

4. Distribution of Minerals:

   • Minerals occur in different types of rocks: Igneous, Metamorphic, and Sedimentary.

   • Generally, metallic minerals are found in Igneous and Metamorphic rock formations (e.g., Iron ore in Sweden, Copper and Nickel in Ontario, Canada).

   • Non-metallic minerals like limestone are found in Sedimentary rock formations (e.g., Limestone deposits in Caucasus region of France).

   • Mineral fuels like coal and petroleum are also found in Sedimentary strata.

   • Continent-wise Distribution (Key Examples - Important for Exams):

     • Asia: China and India have large iron ore deposits. Asia produces more than half of the world's tin (China, Malaysia, Indonesia). China leads in lead, antimony, and tungsten production. Asia also has deposits of manganese, bauxite, nickel, zinc, and copper.
     • Europe: Leading producer of iron ore. Russia, Ukraine, Sweden, and France have large deposits. Eastern Europe and European Russia have deposits of copper, lead, zinc, manganese, and nickel. Switzerland has no known mineral deposits.
     • North America: Mineral deposits located in three zones: Canadian region (iron ore, nickel, gold, uranium, copper), Appalachian region (coal), Western Cordilleras (copper, lead, zinc, gold, silver).
     • South America: Brazil is the largest producer of high-grade iron ore. Chile and Peru are leading producers of copper. Brazil and Bolivia are among the world's largest producers of tin. South America also has large deposits of gold, silver, zinc, chromium, manganese, bauxite, mica, platinum, asbestos, and diamond. Mineral oil is found in Venezuela, Argentina, Chile, Peru, and Colombia.
     • Africa: Rich in mineral resources. World's largest producer of diamonds, gold, and platinum. South Africa, Zimbabwe, and Zaire produce a large portion of the world's gold. Other minerals: Copper, iron ore, chromium, uranium, cobalt, bauxite. Oil is found in Nigeria, Libya, and Angola.
     • Australia: Largest producer of bauxite in the world. Leading producer of gold, diamond, iron ore, tin, and nickel. Rich in copper, lead, zinc, and manganese. Kalgoorlie and Coolgardie areas have the largest deposits of gold.
     • Antarctica: Significant size deposits of coal (Transantarctic Mountains) and iron near the Prince Charles Mountains predicted. Iron ore, gold, silver, and oil are also present in commercial quantities (potential, largely unexploited).

   • Distribution in India (Key Examples - Very Important):

     • Iron: High-grade iron ore found in Jharkhand, Odisha, Chhattisgarh, Madhya Pradesh, Goa, Maharashtra, and Karnataka.
     • Bauxite: Major producing areas are Jharkhand, Odisha, Chhattisgarh, Madhya Pradesh, Gujarat, Maharashtra, and Tamil Nadu. (India is a leading producer).
     • Mica: Deposits mainly in Jharkhand, Bihar, Andhra Pradesh, and Rajasthan. India is the largest producer and exporter of mica globally.
     • Copper: Mainly produced in Rajasthan (Khetri mines), Madhya Pradesh, Jharkhand, Karnataka, and Andhra Pradesh.
     • Manganese: Deposits in Maharashtra, Madhya Pradesh, Chhattisgarh, Odisha, Karnataka, and Andhra Pradesh.
     • Limestone: Major producing states are Bihar, Jharkhand, Odisha, Madhya Pradesh, Chhattisgarh, Rajasthan, Gujarat, and Tamil Nadu.
     • Gold: Kolar Gold Fields (KGF) in Karnataka (deep mines, expensive operation). Some quantity also found in Hutti mines (Karnataka) and Ramagiri Gold Field (Andhra Pradesh).
     • Salt: Obtained from seas, lakes, and rocks. India is one of the world's leading producers and exporters.

5. Uses of Minerals:

   • Gems: Hard minerals used in jewellery (e.g., Diamond, Ruby).
   • Metals: Copper (coins to pipes), Silicon (computer industry, from quartz), Aluminium (automobiles, airplanes, bottling industry, buildings, kitchen cookware - extracted from bauxite).
   • Industrial Uses: Iron (steel production), Manganese (steel), Mica (electrical industry), Limestone (cement industry).

6. Conservation of Minerals:

   • Minerals are non-renewable resources.
   • Formation takes thousands/millions of years; rate of consumption is much faster than formation.
   • Need to reduce wastage in mining and processing.
   • Recycling of metals is crucial (e.g., recycling scrap iron, aluminium).
   • Using substitutes where possible.
   • The 3 R's principle: Reduce, Reuse, Recycle is vital for mineral conservation.

Part 2: Power Resources

1. What are Power Resources?

   • Resources which provide energy (power) for industry, agriculture, transport, communication, and defence.
   • Essential for economic development and improving quality of life.

2. Classification of Power Resources:

   • Conventional Sources: Commonly used for a long time. Examples: Firewood, Fossil Fuels (Coal, Petroleum, Natural Gas), Hydel Power.
   • Non-conventional Sources: Newer sources of energy being developed. Examples: Solar Energy, Wind Energy, Nuclear Power, Geothermal Energy, Tidal Energy, Biogas.

3. Conventional Sources of Energy:

   • A. Firewood:

     • Widely used for cooking and heating, especially in rural areas (over 50% of energy used by villagers).
     • Easy access, but causes deforestation, pollution, and time consumption in collection. Promotes greenhouse gas emissions.

   • B. Fossil Fuels:

     • Formed from the remains of plants and animals buried under the Earth for millions of years, converted by heat and pressure.

     • Main sources: Coal, Petroleum, Natural Gas.

     • Reserves are limited; rate of consumption is far greater than formation.

     • Burning causes pollution (acid rain, greenhouse effect).

     • i. Coal:

       • Most abundantly found fossil fuel. Used as domestic fuel, in industries (iron and steel), steam engines, and to generate electricity (Thermal Power).
       • Formed from giant ferns and swamps buried millions of years ago ('Buried Sunshine').
       • Leading Producers (World): China, USA, Germany, Russia, South Africa, France.
       • Leading Producers (India): Raniganj, Jharia, Dhanbad, Bokaro (Jharkhand/West Bengal belt); also found in Madhya Pradesh, Odisha, Maharashtra, Andhra Pradesh.

     • ii. Petroleum:

       • Found between layers of rocks, drilled from oil fields (onshore and offshore).
       • Thick black liquid ('Black Gold' - due to its value).
       • Sent to refineries for processing into diesel, petrol, kerosene, wax, plastics, lubricants.
       • Chief Producers (World): Saudi Arabia, Iran, Iraq, Qatar, UAE, USA, Russia, Venezuela, Algeria.
       • Chief Producers (India): Digboi (Assam - oldest), Bombay High (Mumbai - offshore), Deltas of Krishna and Godavari rivers.

     • iii. Natural Gas:

       • Found with petroleum deposits; released when crude oil is brought to the surface.
       • Used as domestic and industrial fuel.
       • Major Producers (World): Russia, Norway, UK, Netherlands.
       • Major Producers (India): Jaisalmer, Krishna-Godavari delta, Tripura, offshore areas of Mumbai.
       • Compressed Natural Gas (CNG): Popular eco-friendly fuel (less polluting than petroleum/diesel).

   • C. Hydel Power (Hydroelectricity):

     • Generated from the energy of falling water (from dams). Water turns turbines to generate electricity.
     • 1/4th of the world's electricity is produced by hydel power.
     • Advantages: Renewable (water cycle), non-polluting, promotes irrigation and fishing, relatively cheap once infrastructure is built.
     • Disadvantages: High initial cost, displacement of local communities, affects river ecology, potential dam failure risks, deforestation for dam construction.
     • Leading Producers (World): Paraguay, Norway, Brazil, China.
     • Important Projects (India): Bhakra Nangal, Gandhi Sagar, Nagarjunasagar, Damodar Valley projects.

4. Non-conventional Sources of Energy:

   • Need: Increasing use of fossil fuels leads to shortage and pollution. Non-conventional sources are renewable, eco-friendly alternatives.

   • A. Solar Energy:

     • Energy trapped from the sun.
     • Photovoltaic cells convert sunlight directly into electricity.
     • Used in solar heaters, solar cookers, solar dryers, street lighting, traffic signals.
     • Advantages: Inexhaustible, non-polluting.
     • Disadvantages: Expensive initial setup, diffused source (less effective on cloudy days/night), requires large areas for panels.
     • Potential: High in tropical countries like India. Major solar parks being set up (e.g., Bhadla Solar Park, Rajasthan).

   • B. Wind Energy:

     • Energy harnessed from moving wind using windmills.
     • Windmills connected to generators produce electricity.
     • Wind farms are clusters of windmills.
     • Advantages: Inexhaustible, non-polluting, low operational cost once installed. Safe and clean.
     • Disadvantages: Requires high wind speed consistently, noisy, visual pollution, potential harm to birds, high initial cost, requires large land area.
     • Locations (World): Netherlands, Germany, Denmark, UK, USA, Spain.
     • Locations (India): Coastal regions (Gujarat, Tamil Nadu), Mountain passes. Significant wind farms in Tamil Nadu, Maharashtra, Gujarat, Rajasthan, Karnataka.

   • C. Nuclear Power:

     • Energy stored in the nuclei of atoms of naturally occurring radioactive elements like Uranium and Thorium.
     • Undergoes nuclear fission in reactors to release heat, used to generate electricity.
     • Greatest Producers (World): USA, Europe (France has a high dependency).
     • Deposits in India: Uranium in Rajasthan and Jharkhand. Thorium in Monazite sands of Kerala.
     • Nuclear Power Stations (India): Kalpakkam (Tamil Nadu), Tarapur (Maharashtra), Rawatbhata (Rajasthan), Narora (Uttar Pradesh), Kaiga (Karnataka).
     • Advantages: Produces large amounts of energy from small amounts of fuel.
     • Disadvantages: Generates radioactive waste (difficult disposal), risk of accidents, expensive setup.

   • D. Geothermal Energy:

     • Heat energy obtained from the Earth's interior.
     • Hot springs can be used for heating, bathing, cooking, and generating power.
     • Advantages: Clean, eco-friendly, always available.
     • Disadvantages: Location specific (only feasible near geothermal hotspots), potential release of harmful gases from underground, high installation cost.
     • Locations (World): USA (world's largest geothermal plants), New Zealand, Iceland, Philippines, Central America.
     • Locations (India): Manikaran (Himachal Pradesh), Puga Valley (Ladakh).

   • E. Tidal Energy:

     • Energy generated from ocean tides.
     • Harnessed by building dams at narrow openings of the sea. High tide turns turbines.
     • Advantages: Inexhaustible, non-polluting.
     • Disadvantages: Location specific (requires suitable tidal range), destroys wildlife habitats near the coast, difficult technology, high setup costs.
     • Locations (World): Russia, France, Gulf of Kutch (India - has huge potential).

   • F. Biogas:

     • Gaseous fuel produced from the decomposition of organic waste (dead plant/animal material, animal dung, kitchen waste) by bacteria in biogas digesters.
     • Mainly composed of Methane and Carbon Dioxide.
     • Excellent fuel for cooking and lighting; produces high-quality manure.
     • Advantages: Low cost, easy to operate, makes use of waste, produces manure, clean fuel.
     • Disadvantages: Less efficient in cold weather, requires regular feeding of waste.
     • Potential: High in rural areas.

5. Conservation of Power Resources:

   • Energy saved is energy generated.
   • Promote use of public transport.
   • Switch off lights/fans when not needed.
   • Use energy-efficient appliances (e.g., LED bulbs).
   • Maximize use of non-conventional sources.
   • Prevent wastage of electricity and fuels.

Multiple Choice Questions (MCQs)

1. Which of the following is NOT a characteristic used to identify minerals?
   (a) Colour
   (b) Density
   (c) Hardness
   (d) Weight (Weight depends on size, density is the intrinsic property)

2. Bauxite is an ore of which metallic mineral?
   (a) Iron
   (b) Copper
   (c) Aluminium
   (d) Gold

3. Minerals like Limestone and Coal are typically found in which type of rock formations?
   (a) Igneous Rocks
   (b) Metamorphic Rocks
   (c) Sedimentary Rocks
   (d) Volcanic Rocks

4. The process of extracting minerals lying near the surface by simply digging them out is called:
   (a) Shaft Mining
   (b) Drilling
   (c) Open-cast Mining
   (d) Quarrying

5. Which continent is the leading producer of iron ore globally?
   (a) Asia
   (b) Europe
   (c) North America
   (d) Africa

6. In India, the Kolar Gold Fields are located in which state?
   (a) Andhra Pradesh
   (b) Karnataka
   (c) Jharkhand
   (d) Rajasthan

7. Which of the following is considered a 'Conventional' source of energy?
   (a) Solar Energy
   (b) Wind Energy
   (c) Coal
   (d) Geothermal Energy

8. Petroleum is often referred to as 'Black Gold' because:
   (a) It is black in colour.
   (b) It is found deep underground like gold.
   (c) It is very valuable.
   (d) It is extracted mainly in gold-producing regions.

9. Which non-conventional energy source utilizes heat from the Earth's interior?
   (a) Tidal Energy
   (b) Nuclear Power
   (c) Geothermal Energy
   (d) Biogas

10. Which principle is vital for the conservation of mineral resources?
    (a) Extract, Use, Discard
    (b) Reduce, Reuse, Recycle
    (c) Mine, Refine, Sell
    (d) Explore, Drill, Transport

Remember to correlate these notes with the maps and diagrams given in your NCERT textbook for better understanding, especially regarding the distribution of minerals and power resources. Good luck with your preparation!