Minerals and Energy Resources

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MINERALS AND ENERGY RESOURCES Importance of minerals 1. Minerals are an essential part of our lives.

2. Almost everything we use, from a pin to a building or a ship is made up of minerals.

3. The railway lines and the paving of the roads and our machinery are all made of minerals.

4. Cars, buses, trains, aeroplanes are all made of minerals and even require minerals to run them.

5. Even our food contains minerals

* Toothpaste: Made up of silica, limestone, aluminium oxide.

Fluoride- used to reduce cavities. Made from fluorite. What is a mineral? Minerals are homogenous, naturally occurring substances with a definable internal structure.

*Rock: Combination of homogenous substances called minerals.

Eg: Limestone (single mineral).

Characteristics of minerals A mineral depends upon the physical and chemical conditions under which it forms. The characteristics include: colour, hardness, crystal forms, lustre, density.

Difference between geographer and geologist Geographers study minerals as a part of the earth's crust for understanding of landforms. The also study the distribution of minerals and associated economic activities. - Where?

A geologist studies the formation of minerals, their age and physical and chemical composition. - Why?

* Extraction of minerals- mining.

Occurrence of minerals 1. Usually found in ores.

2. An ore is an accumulation of any mineral mixed with other elements.

3. Mineral content of the ore must be in sufficient quantity to make it economically viable.

Forms 1. Igneous and metamorphic rocks:

*Minerals occur in cracks, crevices, faults or joints.

* Smaller occurrence- veins. Larger occurrence - lodes.

* Formed when minerals in molten/gaseous states are pushed upwards through cavities towards the earth's surface.

* They cool and solidify as they rise.

Eg: Tin, copper, zinc and lead.

2. Sedimentary rocks:

* Minerals occur in beds or layers

* Results of deposition, accumulation and concentration in horizontal strata ( layer).

Eg: Coal and iron ore ( formed over long periods under great heat and pressure).

Gypsum, potash salt, sodium salt (evaporation in arid regions).

3. Residual mass:

* Involves decomposition of surface rocks and the removal of soluble constituents, leaving a residual mass of weathered material containing ores.

Eg: Bauxite.

4. Alluvial deposits:

* Minerals may occur as alluvial deposits in valleys and the base of hills.

* Also called placer deposits. (placer- precious minerals- link)

* Minerals are generally not corroded by water.

* Eg: Gold, silver, tin, platinum.

5. Oceans

* Oceans contain vast quantities of minerals but most are too widely diffused to be of economic significance.

* Some are still available.

* Eg: Common salt, magnesium, bromine and manganese nodules.

Rat-Hole Mining *In most tribal ares of 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 a family member by digging long and narrow tunnels into the ground. This is referred to as rat-hole mining.

Uneven distribution of minerals Even though India has a large variety of minerals, these are unevenly distributed.

* 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 sides of the peninsula, in Gujarat and Assam have the most petroleum deposits.

* Rajasthan with the rock systems has reserves of many non-ferrous minerals.

* The alluvial plains are almost devoid of economic minerals.

* These variations exist due to the differences in the geological structure, processes and time involved in the formation.