CBSE Class 10 Social Science Minerals And Energy Resources Notes Set 02

I. Mode of occurrence of Mineral :

Where are these minerals found.

Minerals are usually found in “Ores”. The term ore is described as accumulation of any mineral mixed with other elements, it should have sufficient concentration to make its extraction viable. The type of formation or structure in which they are found determines their relative ease of mining and cost of extraction.

Minerals Generally Occur in These forms :

(i) In igneous and metamorphic rocks minerals may occur in the cracks, crevices, faults or joints. The smaller occurrences are called vein and the larger are called lodes. They are formed when minerals in liquid / molten & gaseous forms are forced upwards through cavities towards earth’s surface. They cool and solidify as they rise. They include tin, copper, Zinc, lead etc.

(ii) Sedimentary Rocks : No. of minerals occur in beds and layers. They have been formed as a result of deposition, accumulation and concentration. of horizontal strata eg Gypsum, potash salt & sodium salt. They are formed as a result of evaporation in arid region.

(iii) Decomposition of Surface Rocks : Involves the removal of soluble constituents, leaving a residual mass of weathered material containing ores eg. Bauxite.

(iv) Alluvial Deposits : Occur in sands of valley floors and the base of hills. These are called ‘Placer deposits ‘ and are not corroded by water eg gold, silver, tin platinum. (v) Ocean waters contain vast quantities of minerals but most of these are too widely diffused to be of economic significance, however common salt, magnesium & bromine are largely derived.

II. Major Iron Ore Belts in India :

1. Orissa Jharkand Belt : In Orissa high grade hematite ore is found in Badampahar mines in the Mayurbhanj and Kendujhar. In Jharkand haematite iron ore is mined in Gua and Noamundi.

2. Durg – Bastar – Chandrapur belt : Lies in chattisgarh and Maharashtra high grade hematitis are found in Bailadila range of hills in Chatisgarh.

3. Bellavy Chitradurga – Chikmaglur – Tumkur Belt : In Karnataka has large reserves of iron ore. Kudermuch mines located in western Ghats of Karnataka and known to be one of the largest.

4. Maharashtra- Goa Belt : Includes state of Goa and Ratnagir district of Maharashtra. Although ores are not of very high quality yet they are efficiently exploited.

III. Conservation of Energy Resources :

Energy is a basic requirement for economic development. Every sector of national economy agriculture, industry, transport, commercial and domestic needs inputs of energy. There is an urgent need to develop a sustainable path of energy development. India is presently one of the least energy efficient countries in the world. We have to adopt a caution approach for judicious use.
– Using public transport instead of individual.
– Switching of electricity when not in use.
– Using power saving devices.
– Using non conventional sources of power.

Key concepts –

Placer deposits – Minerals that occur as alluvial fans in sands of valley floors, and the base of hills.
Rat-hole Mining – In the tribal areas of North-East India mining is carried out by individuals or communities illegally. The mining is done in the form of a long narrow tunnel known as Rat hole mmmg.
Magnetite – It is the finest iron ore with a very high content of iron up to 70%. It has excellent magnetic qualities, especially valuable in the electrical industry.
Hematite ore – It has slightly lower iron content than magnetite-50-60%

Question and Answers

Question. What are Geo-thermal Energy? Which are the two experimental projects of geothermal energy in India?
Answer. Geo-thermal energy refers to the heat and electricity produced by using the heat from the interior of the earth
Parvati Valley near Manikam in Himachal Pradesh
Puga valley in Ladakh

Question. Why does solar energy in Rajasthan have great potential as non -conventional source of energy?
Answer. Hot and dry region
Clear sky almost whole year
Cheaper installation
Renewable and pollution free energy source.
Government motivation

Question. Write two uses of Mica and also areas famous for mica deposits.
Answer. Used in electric and electronic industries. Areas-
(a) Gaya-Hazaribagh in Jharkhand, and
(b)Ajmer and Beawar in Rajasthan

Question. Give three reasons in favour of the use of “Atomic energy”.
Answer. Coal and natural oil are exhaustible.
Abundant deposits of uranium and thorium in India
Most developed countries are utilizing this energy successfully
It can be useful in fields of medicines and agriculture
Hydel energy is not satisfactory due to environmental issues.

Question. How can we conserve energy resources in India? Explain Using public transpott instead of individual vehicles.
Answer. Switching of electricity when not in use.
Using power saving devices.
Use of non-conventional source of energy as they are renewable and eco- friendly.
In automobiles electrical motors should be introduced.
Intensified exploration and research of new sources of energy.

Question. What are three types of Coal? Write one difference of each type of coal?
Answer.  Lignite coal – low grade brown coal soft with high moisture content. Found in Nevyeli (T.N)
Bituminous Coal – It contains 60-80% of carbon content.
Anthracite – Best quality, contains more than 80% of carbon content.

Question. Why mining activity is often called a “Killer Industry”. Give three reasons.
Answer. High risk involved
Due to poisonous fumes, mines are vulnerable to workers for pulmonary diseases.
Risk of collapsing mines roofs, and fires in coal mines.
Water sources get contaminated.