Coal was formed by the decomposition of dead vegetation buried under the earth about 300 million years ago.Due to natural process the dead vegetation got buried under the soil .

They wear compressed.The temperature alsa rose as they sank deeper
and deeper .Under high pressure and high temperature dead vegetation slowly converted to coal.This process is called Carbonisation.

Formation of coal from dead vegetation:

Coal is a fossil fuel that is formed from the remains of dead vegetation. The process of coal formation is called Carbonization. The formation of coal takes millions of years, and it involves several stages.

Stage 1: Formation of Peat:

The first stage of coal formation is the accumulation of dead plant material in a swampy environment. As the vegetation dies, it sinks to the bottom of the swamp, and it is covered by water and mud. Over time, the dead vegetation accumulates, and it forms a layer of peat. Peat is a brown, fibrous material that is the precursor to coal.

Stage 2: Formation of Lignite:

As more and more plant material accumulates, the weight of the overlying sediments compresses and heats the peat. This process drives off the water and other volatile components, and it increases the carbon content of the remaining material. The result of this process is a soft, brown coal called lignite.

Stage 3: Formation of Bituminous Coal:

As the process of heat and compression continues, the lignite is transformed into bituminous coal. Bituminous coal is a harder, black coal that has a higher carbon content than lignite. It is also the most abundant type of coal.

Stage 4: Formation of Anthracite Coal:

The final stage of coal formation is the transformation of bituminous coal into anthracite coal. This occurs when the coal is subjected to even more heat and pressure. Anthracite coal is a hard, black coal that has a high carbon content and a low volatile content. It is the most valuable type of coal because it burns hotter and cleaner than other types of coal.

Overall, the formation of coal is a slow and gradual process that takes millions of years. It begins with the accumulation of dead plant material in a swampy environment and ends with the formation of anthracite coal.