Class 10 Notes

Class 10 Social Science Notes Chapter 5 (Minerals and energy resources) – Contempory India Book

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Philoid

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Contempory India
Detailed Notes with MCQs of Chapter 5: Minerals and Energy Resources from your 'Contemporary India' textbook. This is a very important chapter, not just for your board exams but also for various government exams, as resources form the backbone of any economy. Pay close attention to the distribution maps and the types of resources found in India.

Minerals and Energy Resources: Detailed Notes

1. What is a Mineral?

  • Definition: A mineral is a homogeneous, naturally occurring substance with a definable internal structure. They are formed through various geological processes without human interference.
  • Characteristics: Minerals vary greatly in colour, hardness, lustre, density, and crystal form. These properties depend on the physical and chemical conditions under which the material forms.
  • Occurrence: Minerals are usually found in ores. An ore is an accumulation of any mineral mixed with other elements. The mineral content must be in sufficient concentration to make its extraction commercially viable.
  • Importance: Minerals are indispensable. Almost everything we use, from a tiny pin to a towering building or a ship, is made from minerals. They are the base for industrial development.

2. Mode of Occurrence of Minerals:

Minerals occur in different types of geological formations:

  • (a) In Igneous and Metamorphic Rocks:
    • Minerals may occur in cracks, crevices, faults, or joints.
    • Smaller occurrences are called veins, and larger ones are called lodes.
    • Formed when minerals in liquid/molten and gaseous forms are forced upward through cavities towards the earth’s surface, cooling and solidifying as they rise.
    • Examples: Tin, copper, zinc, lead.
  • (b) In Sedimentary Rocks:
    • Minerals occur in beds or layers.
    • Formed as a result of deposition, accumulation, and concentration in horizontal strata.
    • Examples: Coal, some forms of iron ore, gypsum, potash salt, sodium salt. These are often formed due to evaporation, especially in arid regions (gypsum, potash, sodium salt).
  • (c) Through Decomposition of Surface Rocks:
    • Involves the removal of soluble constituents, leaving a residual mass of weathered material containing ores.
    • Example: Bauxite (ore of aluminium) is formed this way.
  • (d) As Alluvial Deposits (Placer Deposits):
    • Occur in sands of valley floors and the base of hills.
    • These are deposits of minerals which are not corroded by water.
    • Examples: Gold, silver, tin, platinum.
  • (e) In Ocean Waters and Ocean Beds:
    • Ocean waters contain vast quantities of dissolved minerals, but most are too widely diffused to be economically viable.
    • Examples: Common salt, magnesium, bromine are largely derived from ocean waters.
    • Ocean beds are rich in manganese nodules.

3. Classification of Minerals:

  • (A) Metallic Minerals: Possess lustre, are malleable and ductile, good conductors of heat and electricity.

    • (i) Ferrous Minerals: Contain iron. Account for about three-fourths of the total value of metallic mineral production.
      • Iron Ore:
        • Backbone of industrial development.
        • India has abundant high-grade iron ore.
        • Types:
          • Magnetite: Finest iron ore (up to 70% iron content). Excellent magnetic qualities, valuable in the electrical industry.
          • Hematite: Most important industrial iron ore (50-60% iron content). Most used quantity-wise.
        • Major Iron Ore Belts in India:
          1. Odisha-Jharkhand Belt: High-grade hematite ore. Mines in Badampahar (Mayurbhanj & Kendujhar districts, Odisha), Gua & Noamundi (Singhbhum district, Jharkhand).
          2. Durg-Bastar-Chandrapur Belt (Chhattisgarh & Maharashtra): Very high-grade hematite from Bailadila range of hills (Bastar, Chhattisgarh). Exported to Japan and South Korea via Vishakhapatnam port.
          3. Ballari-Chitradurga-Chikkamagaluru-Tumakuru Belt (Karnataka): Large reserves. Kudremukh mines (known to be one of the largest deposits in the world) exported as slurry via Mangaluru port. (Note: Kudremukh mining stopped due to environmental reasons, but the belt remains important).
          4. Maharashtra-Goa Belt: Includes Ratnagiri (Maharashtra) and Goa. Ores not very high quality but efficiently exploited and exported through Marmagao port.
      • Manganese:
        • Used mainly in manufacturing steel and ferro-manganese alloys (nearly 10 kg needed for 1 tonne of steel).
        • Also used in manufacturing bleaching powder, insecticides, and paints.
        • Distribution: Odisha (largest producer), Madhya Pradesh, Karnataka.
    • (ii) Non-Ferrous Minerals: Do not contain iron. India's reserves are not very large.
      • Copper:
        • Malleable, ductile, good conductor – mainly used in electrical cables, electronics, and chemical industries.
        • Distribution: Balaghat mines (Madhya Pradesh - produces ~52% of India's copper), Khetri mines (Rajasthan), Singhbhum district (Jharkhand).
      • Bauxite:
        • Clay-like substance from which alumina, and later aluminium, is obtained.
        • Formed by decomposition of rocks rich in aluminium silicates.
        • Aluminium is important: combines strength of metals like iron with extreme lightness, good conductivity, and great malleability.
        • Distribution: Amarkantak plateau, Maikal hills, plateau region of Bilaspur-Katni. Odisha is the largest producer (~65% of India's production, Panchpatmali deposits in Koraput district are important). Gujarat, Jharkhand, Maharashtra are other producers.

  • (B) Non-Metallic Minerals: Do not contain metals.

    • Mica:
      • A mineral made up of a series of plates or leaves. Splits easily into thin sheets.
      • Can be clear, black, green, red, yellow, or brown.
      • Excellent dielectric strength, low power loss factor, insulating properties, resistance to high voltage – indispensable for electric and electronic industries.
      • Distribution: Northern edge of the Chota Nagpur plateau. Koderma Gaya–Hazaribagh belt of Jharkhand is the leading producer. Ajmer (Rajasthan), Nellore mica belt (Andhra Pradesh) are other important producers.
    • Rock Minerals:
      • Limestone:
        • Found in association with rocks composed of calcium carbonates or magnesium carbonates. Found in sedimentary rocks.
        • Basic raw material for the cement industry and essential for smelting iron ore in the blast furnace.
        • Distribution: Major producing states are Rajasthan, Madhya Pradesh, Andhra Pradesh, Chhattisgarh, Karnataka, Gujarat, Tamil Nadu.

  • (C) Energy Minerals: Provide energy/power.

    • (i) Conventional Sources: Generally non-renewable (except hydro-electricity).
      • Coal:
        • Most abundantly available fossil fuel in India. Used for power generation, supply energy to industry, and domestic needs.
        • Formed due to compression of plant material over millions of years.
        • Types (based on carbon content, moisture, volatile matter):
          1. Peat: Low carbon, high moisture, low heating capacity.
          2. Lignite: Low-grade brown coal. Soft, high moisture content. Principal reserves in Neyveli (Tamil Nadu). Used for electricity generation.
          3. Bituminous: Most popular coal in commercial use. Buried deep, subjected to increased temperatures. High heating value. Used in metallurgy.
          4. Anthracite: Highest quality hard coal. Highest carbon content (>80%).
        • Occurrence in India:
          1. Gondwana Coalfields (~200 million years old): Located in Damodar valley (West Bengal-Jharkhand - Jharia, Raniganj, Bokaro are important coalfields), Godavari, Mahanadi, Son, and Wardha valleys. Contains metallurgical coal.
          2. Tertiary Coalfields (~55 million years old): Occur in the northeastern states of Meghalaya, Assam, Arunachal Pradesh, and Nagaland.
      • Petroleum (Mineral Oil):
        • Next major energy source after coal. Provides fuel for heat and lighting, lubricants for machinery, and raw materials for industries (synthetic textiles, fertilizers, chemical industries).
        • Occurrence: Found in anticlines and fault traps in sedimentary rocks of tertiary age. Occurs where oil is trapped in the crest of an upfold (anticline) or between porous and non-porous rocks separated by a fault. Gas, being lighter, usually occurs above the oil.
        • Distribution: Mumbai High (~63% of India's production), Gujarat (~18%), Assam (~16% - oldest oil-producing state, Digboi, Naharkatiya, Moran-Hugrijan). Ankleshwar is an important field in Gujarat.
        • Oil Refineries: Act as a "nodal industry" for synthetic textile, fertilizer, and chemical industries. Major refineries: Digboi, Mathura, Panipat, Jamnagar (Reliance - largest private sector), Kochi, Chennai, etc.
      • Natural Gas:
        • Important clean energy resource. Found with or without petroleum.
        • Used as an industrial raw material (petrochemical industry), fuel for power generation, and increasingly as fuel for vehicles (CNG). Considered environmentally friendly (low CO2 emissions).
        • Distribution: Krishna-Godavari basin (large reserves discovered), Mumbai High and allied fields, Gulf of Cambay (Khambat). Andaman and Nicobar islands also have reserves.
        • Pipeline: The 1700 km long Hazira-Vijaipur-Jagdishpur (HVJ) cross-country gas pipeline links Mumbai High and Bassein with fertilizer, power, and industrial complexes in western and northern India.
      • Electricity: Generated mainly in two ways:
        • Hydroelectricity: Generated by fast-flowing water (renewable). India has numerous multi-purpose projects like Bhakra Nangal, Damodar Valley Corporation, Kopili Hydel Project, etc.
        • Thermal Power: Generated using coal, petroleum, and natural gas (non-renewable). Over 310 thermal power plants in India. (Examples: Singrauli, Ramagundam, Talcher, Korba, Neyveli).
    • (ii) Non-Conventional Sources: Renewable, eco-friendly, emerging sources.
      • Nuclear or Atomic Energy:
        • Obtained by altering the structure of atoms. Releases immense energy.
        • Uses Uranium and Thorium. Uranium and Thorium deposits are found in Jharkhand, Aravalli ranges of Rajasthan. Thorium is found in Monazite sands of Kerala.
        • Major Nuclear Power Stations: Narora (UP), Rawat Bhata (Rajasthan), Kakrapar (Gujarat), Tarapur (Maharashtra), Kaiga (Karnataka), Kalpakkam (Tamil Nadu).
      • Solar Energy:
        • India is a tropical country with enormous potential for tapping solar energy.
        • Photovoltaic technology converts sunlight directly into electricity.
        • Becoming popular in rural/remote areas. Used for heating, lighting, cooking (solar cookers). Reduces dependence on firewood and dung cakes.
        • Largest solar plant at Madhapur near Bhuj (Gujarat).
      • Wind Power:
        • India has great potential for wind power. Largest wind farm cluster is located in Tamil Nadu (from Nagarcoil to Madurai).
        • Other significant locations: Andhra Pradesh, Karnataka, Gujarat, Kerala, Maharashtra, Lakshadweep.
        • Nagarcoil and Jaisalmer are well known for effective use of wind energy.
      • 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 than kerosene, dung cake, and charcoal.
        • Produces high-quality manure. Often set up at municipal, cooperative, and individual levels. (Gobar Gas plants in rural areas).
      • Tidal Energy:
        • Oceanic tides can be used to generate electricity. Floodgate dams are built across inlets.
        • Potential sites in India: Gulf of Kutch (Gujarat), Gulf of Cambay (Khambat) (Gujarat), Gangetic delta in Sunderban regions (West Bengal).
      • Geothermal Energy:
        • Heat and electricity produced by using the heat from the interior of the Earth.
        • Where geothermal gradient is high, high temperatures are found at shallow depths. Groundwater absorbs heat and turns into steam, used to drive turbines.
        • Two experimental projects in India: Parvati valley near Manikaran (Himachal Pradesh) and Puga Valley (Ladakh).

4. Hazards of Mining:

  • Health Risks for Miners: Constant threat from dust and noxious fumes (pulmonary diseases like black lung disease). Risk of collapsing mine roofs, inundation (flooding), and fires.
  • Environmental Impact: Water sources in the region get contaminated. Dumping of waste and slurry leads to degradation of land, soil, and increase in stream and river pollution. Deforestation often accompanies mining.
  • Safety Regulations: Strict safety regulations and implementation of environmental laws are essential to prevent mining from becoming a "killer industry".
  • Rat-Hole Mining: Dangerous, prevalent in some areas like Jowai and Cherrapunji (Meghalaya) for coal, often done by individuals/families in narrow tunnels.

5. Conservation of Minerals and Energy Resources:

  • Need for Conservation:
    • Minerals are non-renewable resources (except hydro).
    • Total volume of workable mineral deposits is finite (only 1% of earth's crust).
    • Geological processes of mineral formation are extremely slow (millions of years).
    • Continued extraction leads to increasing costs as minerals have to be mined from greater depths, decreasing quality.
    • Over-exploitation leads to environmental degradation.
  • Methods for Conservation:
    • Sustainable Use: Use mineral resources in a planned and sustainable manner.
    • Improved Technology: Allow use of low-grade ores at low costs.
    • Recycling: Recycling of metals (using scrap metals).
    • Substitution: Using other substitutes (e.g., plastics, composites instead of metals where possible).
    • Energy Conservation:
      • Use public transport systems instead of individual vehicles.
      • Switch off electricity when not in use.
      • Use power-saving devices (LED bulbs, energy-efficient appliances).
      • Greater use of non-conventional (renewable) sources of energy.
    • Mantra: "Energy saved is energy produced".

Multiple Choice Questions (MCQs):

  1. Which one of the following minerals is formed by the decomposition of rocks, leaving a residual mass of weathered material?
    a) Coal
    b) Bauxite
    c) Gold
    d) Zinc

  2. Koderma-Gaya-Hazaribagh belt of Jharkhand is the leading producer of which one of the following minerals?
    a) Bauxite
    b) Mica
    c) Iron Ore
    d) Copper

  3. Minerals are deposited and accumulated in the strata of which of the following rocks?
    a) Sedimentary rocks
    b) Metamorphic rocks
    c) Igneous rocks
    d) None of the above

  4. Which one of the following minerals is contained in the Monazite sand?
    a) Oil
    b) Uranium
    c) Thorium
    d) Coal

  5. Which type of coal is metallurgically most valuable and primarily found in the Gondwana coalfields?
    a) Lignite
    b) Peat
    c) Bituminous
    d) Anthracite

  6. The largest wind farm cluster in India is located in which state?
    a) Gujarat
    b) Tamil Nadu
    c) Rajasthan
    d) Karnataka

  7. Which of the following is a non-ferrous mineral?
    a) Iron Ore
    b) Manganese
    c) Cobalt
    d) Copper

  8. The Bailadila range of hills in Chhattisgarh is known for the deposit of which mineral?
    a) Bauxite
    b) High-grade Hematite Iron Ore
    c) Copper
    d) Manganese

  9. The Hazira-Vijaipur-Jagdishpur (HVJ) pipeline transports which energy resource?
    a) Petroleum
    b) Coal Slurry
    c) Natural Gas
    d) Electricity

  10. Which of the following is NOT a conventional source of energy?
    a) Coal
    b) Petroleum
    c) Natural Gas
    d) Solar Energy

Answers to MCQs:

  1. b) Bauxite
  2. b) Mica
  3. a) Sedimentary rocks
  4. c) Thorium
  5. c) Bituminous (While Anthracite is highest quality, Bituminous is the most used metallurgical coal found abundantly in Gondwana fields)
  6. b) Tamil Nadu
  7. d) Copper
  8. b) High-grade Hematite Iron Ore
  9. c) Natural Gas
  10. d) Solar Energy

Remember to study the maps in your textbook carefully, especially showing the distribution of minerals and energy resources. Good luck with your preparation!

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