CBSE Class 8 Answered

Formation of Coal

• Coal was formed by the decomposition of large land plants and trees buried under the Earth about 300 million years ago.
• About 300 million years ago, the Earth had dense forests in the low-lying wet areas.
• Due to natural calamities like earthquakes, volcanoes, floods, etc.  these forests got buried under the surface of the Earth.
• As more soil got deposited on them, they were compressed.
• As a result, the temperature also rose as they sank deeper and deeper.
• Due to high pressure and temperature and the absence of air, the wood of the buried forest plants and trees slowly got converted into coal.
• The slow process by which the dead plants buried under the Earth have become coal is called as carbonisation.
• Since coal was formed from the remains of the plants, it is called a fossil fuel.