...eventually forming coal deposits of today.
“Carboniferous” period, which lasted for 60 million years and started about 359 million years ago is used to refer to two periods, the Mississippian (older) and the Pennsylvanian (younger). The vegetation was abundant because of Pennsylvania proximity to the equator. The plants provided large quantities of leaves, twigs, branches, and trunks that fell into the swamps. The fallen parts were shielded from oxidation by the water and thus did not rot. This continuous supply of vegetation gradually accumulated as thick masses of wood debris called peat. This process concentrated the carbon and eventually turned the peat into coal. The bigger the pressure, the higher the number of volatile compounds that were forced out, making the coal richer in carbon, the chief element in coal that burns. Coal formed from buried Pennsylvanian-age swamp vegetation is burned to generate electricity and to make iron and steel.
