Coal is a readily combustible black or brownish-black sedimentary rock normally occurring in rock strata in layers or veins called coal beds. The harder forms, such as anthracite coal, can be regarded as metamorphic rock because of later exposure to elevated temperature and pressure. It is composed primarily of carbon along with variable quantities of other elements, chiefly sulfur, hydrogen, oxygen and nitrogen.
Coal starts as layer upon layer of annual plant remains accumulating slowly that were protected from biodegradation by usually acidic covering waters that gave a natural antiseptic effect combating microorganisms and then later mud deposits protecting against oxidization in the widespread shallow seas — mainly during the Carboniferous period — thus trapping atmospheric carbon in the ground in immense peat bogs that eventually were covered over and deeply buried by sediments under which they metamorphosed into coal. Over time, the chemical and physical properties of the plant remains (believed to mainly have been fern-like species antedating more modern plant and tree species) were changed by geological action to create a solid material.
Coal, a fossil fuel, is the largest source of energy for the generation of electricity worldwide, as well as one of the largest worldwide anthropogenic sources of carbon dioxide emissions. Gross carbon dioxide emissions from coal usage are slightly more than those from petroleum and about double the amount from natural gas.[1] Coal is extracted from the ground by mining, either underground or in open pits.
Contents |
|
Beckley Register-Herald
Commissioner John Aliff promised supporters he would ask Beaver Coal President Woody Duba to be a willing supporter of the project. ...
and more »
535px x 800px | 58.10kB
[source page]
coal creek walk 045 jpg 14 Jan 2008 08 55 147k coal creek walk 046 > 14 Jan 2008 08 55 7k coal creek walk 046 jpg 14 Jan 2008 08 56 58k coal creek walk 047 > 14 Jan 2008 08 56 7k
