Coal is formed in a swampy depositional environment that includes the remains of trees and shrubs. This swampy environment is able to bury plant life quickly before it rots. Once buried, the plant life is heated and compressed to form coal.
Though produced from plant life buried in the Earth for millions of years, coal plays an important role in providing the energy used by modern people. Knowing the depositional environment of coal allows geologists to search for the fossil fuel in areas where the rock layer contains those deposits. Understanding the forming process makes mining coal much more efficient.