Coal formation

Conditions

• Coal forms mainly from plants living in swampy environments in waterlogged soils — mostly found in swamps.

   

  3 conditions needed:

  1.     Wet (waterlogged)

  2.     Low O₂

  3.     Lots of plant growth

step 1

Step 1: Plants live and die in a low O₂ environment so they don't get fully decomposed. They build up layers and peat forms. Peat is a soft brown soil made from partially decomposed material.

step 2

Step 2: Layers of sand and mud cover the peat over time. As layers build up, temperature and pressure get higher. Over millions of years the peat turns to coal.

The stages

3 stages of coal formation from peat

1.     Lignite — soft brown coal, low energy (first coal form from peat)

2.     Bituminous coal — forms from more pressure and heat, medium energy, darker and harder

3.     Anthracite — very hard shiny black coal, high energy