Mineral : A naturally occurring substance that has a definite chemical composition is a mineral.
Rock : A rock is an aggregate of one or more minerals but without definite composition of a constituent of mineral.
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.
Mining : Mining is the extraction of valuable minerals or other geological materials from the earth, usually from an orebody, lode, vein, seam, reef or placer deposit.
Open Cast Mining : Open-pit, open-cast or open cut mining is a surface mining technique of extracting rock or minerals from the earth by their removal from an open pit or borrow.
Shaft mining : Shaft mining is a form of underground mining using shafts driven vertically from the top down into the earth to access ore or minerals.
Drilling : Drilling is a cutting process that uses a drill bit to cut a hole of circular cross-section in solid materials.
Quarrying : Quarrying is the process of removing the rock, sand, gravel or other minerals from the ground in order to use them to produce materials for construction or other uses.
Metallic Minerals : Metallic minerals are minerals which contain one or more metallic elements.
Metals are hard substances that conduct heat and electricity and have a characteristic lustre or shine. Iron ore, bauxite, manganese ore are some examples of such minerals.
Non-Metallic Minerals : 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.
Ferrous minerals : These minerals contain iron content. Examples – Iron ore, manganese, etc.
Non-ferrous minerals: These minerals do not contain iron content. Examples – Copper, aluminium etc.
Renewable sources of energy: These energy resources can be replenished. They may be renewed after use. Example-solar energy, wind energy, etc.
Non-renewable sources of energy: These sources of energy are exhaustible. The deposits cannot be renewed or replenished after use. Example-fossil fuels.
Solar energy: Solar power is the conversion of energy from sunlight into electricity, either directly using photovoltaics (PV), indirectly using concentrated solar power, or a combination.
Wind energy: Wind power is the use of air flow through wind turbines to mechanically power generators for electric power.
Biogas: Biogas typically refers to a mixture of different gases produced by the breakdown of organic matter in the absence of oxygen.
Geothermal energy: Geothermal energy is the heat emanating from underneath the surface of the earth.
Minerals can be defined as a homogenous, naturally occurring substance with a definable internal structure. Minerals are usually found in “ores”.
Ore means an accumulation of any mineral mixed with other elements. Minerals are classified on the basis of a wide range of colours, hardness, crystal forms, lustre and density that a particular mineral possesses.
Rocks are combinations of homogenous substances called minerals. Some rocks, for instance, limestone, consist of a single mineral only, but majority of the rocks consist of several minerals in varying proportions.
Importance of Minerals
Everything we use, eat and drink has minerals.
Economic development of people or nations can be vastly accelerated by the presence of valuable minerals.
They make our life comfortable and convenient.
They are also responsible for all the biological processes on earth.
Different appearances and occurrence in various forms, in a wide range of colours, hardness, forms lustre and density. As all minerals are formed from, a certain combination of elements which depends upon the chemical and physical conditions under which the mineral forms. The geologists use these properties to categorise minerals.
Rocks containing minerals: Compacted substances that comprise the earth’s crust are called rocks.
Rocks are the naturally formed aggregate of mineral particles. It is the minerals that impart their texture, colour, shape, hardness or softness to rocks.
For example: limestone is a rock consists of a single mineral.
Majority of rocks on the earth’s crust are a combination or an aggregate of different minerals.
Over 3000 minerals have been identified so far; only a few are abundantly found.
Minerals are an indispensable part of our lives :
(i) Almost everything we use, from a tiny pin to a towering building or a big ship, all are made from minerals.
(ii) The railway lines and the tarmac (paving) of the roads, our implements and machinery too are made from minerals.
(iii) Cars, buses, trains, aeroplanes are manufactured from minerals and run on power resources derived from the earth.
(iv) Even the food that we eat contains minerals.
(v) In all stages of development, human beings have used minerals for their livelihood, decoration, festivities, religious and ceremonial rites.
Mode of Occurrence of Minerals
In igneous and metamorphic rocks: The smaller occurrences are called veins and the larger occurrences are called lodes. Examples: tin, copper, zinc, lead, etc.
In sedimentary rocks: In these rocks, minerals occur in beds or layers. Coal, iron ore, gypsum, potash salt and sodium salt are the minerals found in sedimentary rocks.
By decomposition of surface rocks: Decomposition of surface rocks and removal of soluble constituents leaves a residual mass of weathered material which contains ores. Bauxite is formed in this way.
As alluvial deposits: These minerals are found in sands of valley floors and the base of hills. These deposits are called placer deposits. Examples; gold, silver, tin, platinum, etc.
Certain minerals may occur as alluvial deposits in sands of valley floors and base of hills. These deposits are called ‘placer deposits’. They generally contain minerals which are not corroded by water. Gold, silver, tin and platinum are examples of some important minerals found in ‘placer deposits’.
In ocean water: Most of the minerals in ocean water are too widely diffused to be of economic importance. But common salt, magnesium and bromine are mainly derived from ocean waters.
Types of Minerals
Metallic minerals are minerals which contain one or more metallic elements.
Metallic Minerals are further sub-divided into ferrous and non-ferrous.
Ferrous (containing iron) are iron ore, manganese ore, chromite, pyrite, nickel and cobalt.
Non-ferrous (containing metals other than iron) — gold, silver, copper, lead, bauxite, tin and magnesium.
The non-metallic minerals do not contain metals. Limestone, mica and gypsum are examples of such minerals.
Non-metallic Minerals: They are limestone, nitrate, potash, mica, gypsum, coal, petroleum, etc.
Iron ore: Basic mineral, the backbone of industrial development.
There are four varieties of iron ore:
Magnetite: contains 70% iron, finest quality, with magnetic properties.
Hematite: contains 60% to 70% iron, most important industrial iron ore.
Limonite: contains 40% to 60% iron.
Siderite: contains 40% to 50% iron.
Major iron ore belts in India: Odisha – Jharkhand Belt; Durg – Bastar – Chandrapur Belt; Bellary – Chitradurga – Chikmaglur – Tumkur Belt; Maharashtra – Goa Belt.
Well-known iron ore mines: Durg and Bastar districts of Chhattisgarh, Paschimi and Purbi Singhbhum districts of Jharkhand, Sundargarh, Kendujhar and Mayurbhanj districts of Odisha, North Goa, Chikmagalur and Bellary district of Karnataka, Ratnagiri of Maharashtra.
(a) It lies in Chhattisgarh and Maharashtra and comprises of high grade hematite iron ore.
(b) Very high grade hematites are found in the famous Bilabial range of hills in the Bastar district of Chhattisgarh.
(c) The range of hills comprises of 14 deposits of super high grade hematite iron ore.
(d) Iron ore from these mines is exported to Japan and South Korea via Visakhapatnam port.
Odisha-Jharkhand belt :
(i) In Odisha, high grade hematite ore is found.
(ii) It is found in Badampahar mines in the Mayurbhanj and Kendujhar districts.
(iii) In the adjoining Singbhum district of Jharkhand, hematite iron ore is mined in Gua and Noamundi.
Bellary-Chitradurga-Chikmaglur-Tumkur belt in Karnataka has large reserves of iron ore.
(i) The Kudermukh mines located in the Western Ghats of Karnataka are a 100 per cent export unit.
(ii) Kudremukh deposits are known to be one of the largest in the world.
(iii) The ore is transported as slurry through a pipeline to a port near Mangalore.
The main reserves of manganese ore are found in Karnataka, Odisha, Madhya Pradesh, Andhra Pradesh, Jharkhand, Maharashtra and Goa.
Two uses of manganese are:
(i) Manganese compounds are used in dry-cell batteries, matches, fireworks, etc.
(ii) Manganese is used as an alloying agent for aluminium.
(iii) It is used to manufacture bleaching powder, insecticides, paints.
It is used for making utensils, electric wires and alloys. Copper reserves are concentrated in Madhya Pradesh, Rajasthan, Jharkhand, Gujarat, Karnataka and Andhra Pradesh.
Uses of copper :
(i) In manufacturing electrical cables.
(ii) In electronic industries.
(iii) In chemical industries.
The two leading copper producing states of India are Madhya Pradesh and Rajasthan.
Bauxite: It is an ore from which aluminium is obtained.
Aluminium is gaining importance because of its extreme lightness, good conductivity and great malleability. It combines the strength of metals such as iron.
It is mainly found in Amarkantak Plateau, Maikal Hills and the plateau region of Bilaspur-Katni. Koraput district in Odisha has large deposits. Odisha is the largest bauxite producing state. Others are Gujarat, Maharashtra and Jharkhand.
Mica: It is used in electrical and electronic industries. Jharkhand, Bihar, Andhra Pradesh and Rajasthan are major producers.
Mica is the non-metallic mineral which can be split easily into thin sheets.
Mica is used in industries due to its excellent dielectric strength, low power loss factor, insulating properties and resistance to high voltage.
Plastic industry uses mica as an extender and filler.
Mica is :
(i) Excellent dielectric in strength and has a low power loss factor.
(ii) It has insulating properties and resistance to high voltage.
(iii) Most indispensable mineral used in electric and electronic industries.
Limestone is composed of calcium carbonate or calcium and magnesium carbonates. It is used in the cement industry, smelting of iron and in chemical industries. Reserves are found in Madhya Pradesh, Chhattisgarh, Andhra Pradesh, Rajasthan, Gujarat, Karnataka and Himachal Pradesh.Limestone (rock mineral) is the basic raw material for the cement industry and essential for smelting iron ore in the blast furnace. It is found in sedimentary rocks of most geological formations.
All types of minerals are exhaustible resources. Other serious problems associated with minerals are production and accumulation of wastes at various stages of mining, processing as well as use.
Efficiency in Mining
Present technologies are inadequate in terms of their efficiency. The world has yet to evolve a really efficient technology suited to present day environment called the technology of benefaction.
Example:, A lot of feed stock use to go waste during petroleum refining; today these wastes are utilized to make many by-products.
The mining activity is injurious to the health of the miners and environment as :
(i) The dust and noxious fumes inhaled by miners make them vulnerable to pulmonary diseases.
(ii) The risk of collapsing mine roofs.
(iii) Inundation and fires in coal mines are a constant threat to miners.
(iv) The water sources in the region get contaminated due to mining.
(v) Dumping of waste and slurry leads to degradation of land, soil and increase in stream and river pollution.
Substitutes: Scarce minerals can be substituted by developing biodegradable alternatives.
For example, Copper was earlier used extensively in electrical industries. But now besides aluminium, many other materials are used to conserve precious copper.
Recycling: All over the world, mini steel plants are using scrap iron, which are the best examples of recycling. It helps reduce wastes, but efficient recycling technologies have yet to be developed. Recycling is very expensive. Problems also arise on account of mixing together of various types of minerals, otherwise products made from iron, copper, lead, zinc and almost all types of minerals can be recycled for more.
Minimised exports: Exports should be minimised and value added manufactured products should be exported.
Mineral resources are finite and non-renewable. Therefore, A concerned effort has to be made in order to use them in a planned and sustainable manners.
Energy Resources: Energy is the ability to do work, it is also called power.
The modern unit of measurement of power is Watt. 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 – The Source of Power
The chief sources of power are energy from fossil fuels, such as coal, petroleum, natural gas, nuclear materials, falling water, sun, wind, etc.
Wind, sun rays and falling water are converted into electricity while others like coal, petroleum and natural gas are applied directly in motor vehicles and machines.
Fossil fuels require combustion; they produce many gases and wastes causing damage to the environment. Two-fifth of the global energy consumption comes from burning oil and the rest from burning coal and natural gas.
Energy is a basic requirement for economic development.
Every sector of the national economy needs the input of energy.
Consumption of energy in all forms has been steadily rising all over the country.
Rising prices of oil and gas and their potential shortage have raised uncertainties about the security of energy supply in the future.
Energy can be generated from fuel minerals like coal, petroleum, natural gas, uranium and from electricity.
Coal: Coal is the prime source of energy, often called the “Mother of Industries” or “Black Gold”. It was the basis of the industrial revolution. It is used as a raw material in the iron and steel and chemical industries. It is the main fuel for producing thermal power. India ranks 7th in the world in coal reserves.
Types of Coal
Contains 80% carbon, hard, black and compact, found only in Jammu and Kashmir. It is the highest quality hard coal.
60-80% carbon, widely used. It has a special value for smelting iron in blast furnaces.
60% of carbon, low grade. It is called “brown coal”. Lignite is a brown coal which is soft with high moisture content. It is used for generating electricity.
<50% carbon and burns like wood.Peat has low carbon and high moisture content and low heating capacity.
Petroleum: Liquid fossil fuel, wells are dug or drilled on land or offshore to bring oil to the surface. This crude oil is transported to refineries where it is changed into gasoline and petrochemicals.
Petroleum refineries serve as ‘nodal industries’ for chemical, fertilizer and synthetic textile industries as various products are obtained during refining petroleum.
It provides fuel for heating, lighting, running machineries, vehicles, lubricants and raw materials for some manufacturing plastics, chemicals, etc.
Importance of Petroleum
(i) Petroleum is the major energy source in India.
(ii) Provides fuel for heat and lighting.
(iii) Provides lubricant for machinery.
(iv) Provides raw material for a number of manufacturing industries.
(v) Petroleum refineries act as nodal industry for synthetic, textile, fertilizer and chemical industries.
Its occurrence : (i) Most of the petroleum occurrences in India are associated with anticlines and fault traps.
(ii) In regions of folding, anticline or domes, it occurs where oil is trapped in the crest of the up fold.
(iii) Petroleum is also found in fault traps between porous and non-porous rocks.
Natural Gas: A clean energy resource associated with petroleum. It can be extracted easily by drilling wells. Does not require processing, does not emit CO2 and burns hotter and clearer, is cheaper and can be used to generate electricity, but it is limited. Used as a source of energy as well as an industrial raw material in the petrochemical industry.
In a power-deficient country, natural gas is a precious gift.
(i) It can be used as a source of energy. It takes less time to build a power plant based on natural gas.
(ii) It can be used as an industrial raw material in petrochemical industry.
(iii) It can be used in building the fertiliser plants and thereby encouraging the use of fertilizers. It can boost agricultural production.
(iv) Through easy transportation by way of pipelines, its utility is further increased.
(v) Use of Compressed Natural Gas (CNG) for vehicles to replace liquid fuels is gaining wide popularity in the country.
(vi) Natural gas is a clean source of energy.
(vii) It is an environment–friendly fuel because of the low carbon emission.
Electricity : Electricity is generated mainly by different methods. Thermal Electricity is obtained by using coal, petroleum and natural gas.
Hydroelectricity is produced from water released at a great force from a high head. Nuclear Electricity is produced from uranium and thorium.
The six nuclear power stations of India are :
(i) Narora nuclear power station
(ii) Kakrapar nuclear power station
(iii) Tarapur nuclear power station
(iv) Kaiga nuclear power station
(v) Kalpakkam nuclear power station
(vi) Rawat Bhata nuclear power station
Non-conventional sources of Energy: The potential of non-conventional sources of energy is large. They use renewable resources for energy generation.
Following are the six main non-conventional sources of energy: namely, solar energy, wind energy, biomass energy, geothermal energy, tidal energy and hydro power.
Geothermal Energy: 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.
Solar Energy: Photovoltaic technology converts sunlight directly into electricity. Solar energy is used for cooking, pumping, heating of water, refrigerator and street lighting. India is a tropical country. It has enormous possibilities for trapping solar energy. Solar energy is becoming popular in rural and remote areas.
Wind Energy: India has a wind power potential of 20,000 MW.India now ranks as a ‘wind super power’ in the world. The largest wind farm cluster is located in Tamil Nadu from Nagercoil to Madurai. Apart from these, Andhra Pradesh, Karnataka, Gujarat, Kerala, Maharashtra and Lakshadweep have important wind farms. Nagercoil and Jaisalmer are well-known for effective use of wind energy in the country.
Biogas: Shrubs, farm wastes, animal and human wastes are used to produce biogas for domestic consumption in the rural areas.
Other non – conventional sources include geothermal energy, tidal energy and wave energy.
Conservation of Energy Resources
Energy is a basic requirement for economic development. Every sector of the economy needs inputs of energy for its development.
Most of the energy resources are limited.
Due to industrialisation, modernisation and urbanisation, the consumption of energy in all forms has been steadily rising all over the country.
We can conserve energy resources by:
(i) Developing a sustainable path of energy development, i.e., energy development but not at the cost of environment or needs of future generation.
(ii) Judicious use of limited energy resources.
(iii) Wastage of minerals should be minimised.
(iv) Modern technology should be used for the exploitation of energy resources.
(v) Export of energy resources should be minimised.
Reasons for Conservation
(i)The strong dependence of industry and agriculture upon minerals.
(ii)The process of mineral formation is slow.
(iii)They are non-renewable.
Need to develop a sustainable path of energy development, i.e., energy development but not at the cost of environment or needs of future generation.
Following efforts have to be made to use mineral resources in a planned and sustainable manner :
(i) Recycling of metals: We should recycle the metal or metal-made products to prevent its scarcity. For example: Used steel blade should be sent for recycling, so that the steel can be used again for other purposes.
(ii) Improved technologies need to be evolved: Traditional technologies should be replaced new and improved technologies, so that the wastage can be minimised.
(iii) Use of substitute or alternative resources : The resources which cannot be recycled or reused should be replaced with the recyclable resources, e.g., use of green gas instead of coal for cooking purpose.
|Class 10 Geography – Notes & Study Material|