Where does coal typically form?

Coal typically forms in swampy environments where plant material accumulates over millions of years. These areas, often characterized by stagnant, waterlogged conditions, allow for the slow decomposition of plant matter. When this organic debris is buried under sediment and subjected to heat and pressure over geological time, it transforms into coal through a process called coalification.

Swamps are ideal settings for this process because the waterlogged conditions prevent complete decay, allowing thick layers of peat to accumulate. Through continued compression and heat from overlying materials, peat ultimately transforms into coal. This formation process is tied closely to the types of vegetation that exist in these ecosystems, as dense plant growth contributes to the organic material necessary for coal formation.

In contrast, oceans, deserts, and mountains do not provide the same conditions conducive to coal formation. Oceans primarily facilitate the deposition of different sedimentary rocks rather than coal, while deserts lack the required vegetation and waterlogged conditions. Mountains, although they may contain coal deposits due to tectonic processes that uplift sedimentary layers, do not themselves act as the original environment where coal is formed.