Question

Where do we get coal and how is it formed? ​

Answer 1

$\underline\mathfrak{formation \: of \: coal}$

• The formation of coal takes millions of years, which is why it is an exhaustible and non-renewable natural resource.
• It was formed around 300 million years ago when the earth was covered with swampy forests.
• When plants in these forests- mainly trees, mosses, ferns, and reeds died, they fell into the swamps.
• Thus, there was a thick layer of dead vegetation in the swamp formed.
• As years passed, more and more plants died and many such layers were formed, one above each other.
• The topmost layers compressed the layers below. Heat and pressure caused some physical and chemical changes and eventually, some carbon-rich deposits were formed.

$\underline\mathfrak{Where \: do \: we \: get \: coal?}$

• It is obtained from the underground seams, which are the layers of ores and are thick enough to be mined with profitable results.
• There are two ways in which mining can be done- underground and open-pit. Determining the type of mining depends on the depth of the deposit.
• Vertical shafts are dug to access the deposits through underground mining, whereas in surface or open-pit mining, soil and rocks that lie on top of the mineral deposits are removed.
• The cost of surface mining is lesser than that of underground mining. This is why the surface mining is more dominant.