What happens during coal formation after plants die and fall to the bottom of a swamp?
After plants die and fall to the bottom of a swamp, they undergo a process of decomposition and compacting. Over millions of years, layers of dead plant matter accumulate and are slowly buried by sediment. The pressure from the weight of the sediment compacts the plant material, causing it to undergo physical and chemical changes.
As the plant material undergoes this process of compaction, it gradually transforms into peat, which is an accumulation of partially decayed plant material. Over time, with increasing pressure and temperature, the peat undergoes further transformation into lignite, then sub-bituminous coal, bituminous coal, and ultimately, anthracite coal.
Coal formation is a slow and gradual process that occurs over millions of years, under specific conditions of pressure, temperature, and time. The quality and type of coal that is formed depend on these factors, as well as the type of plant material that originally accumulated in the swamp.