What is Coal? How is it formed?
Coal is a combustible rock which consists of carbonized plant matter, most notably peat moss, that can be and that has been used as fuel around the world for centuries. Coal, however, is a non-renewable source of energy due to the fact that it takes millions of years to form. So, when we run out of the coal we have, it won't reform for a very long time. However, coal deposits in Virginia are very abundant, especially in the Appalachian Plateau, and will not run out in the near future. But it is still imperative that we limit its use to not only support the material's longevity but to also protect the environment from its damaging effects. In terms of geologic history, the coal that is presently available in Virginia was created 280 to 360 million years ago. All the coal deposits in Virginia were created in the Phanerozoic Eon, but, interestingly, were created in two different geologic eras: the Mesozoic and Paleozoic. In the Eastern Coalfields of the Piedmont region, sedimentary bituminous coal formed during the Triassic period of the early Mesozoic era. In the Valley Coalfields of the Valley and Ridge region, metamorphic semi-anthracite coal primarily formed during the early Mississippian (early Carboniferous) period of the late Paleozoic era. And, finally, in the Appalachian Plateau Coalfields of southeastern Virginia, mainly sedimentary bituminous coal formed during the Pennsylvanian (late Carboniferous) period of the late Paleozoic era. In Virginia, this coal was formed from pressurized layers of dead plants and ferns that once grew in swamps hundreds of millions of years ago. Once water and debris formed on top of these plants and ferns, pressure caused their compression and cementation, creating the coal we know today. However, the semi-anthracite was formed in a more metamorphic process that owes it existence to more extreme heat and pressure deeper within Earth's crust.