| Themes > Science > Earth Sciences > Geology > Coal > About Coal, Generalities > Natural Occurrence of Coal |
Coal is found in beds or seams interstratified with shales, clays, sandstones, or (rarely) limestones. It is usually underlaid by an underclay (a layer of clay containing roots of plants). The coal is removed by strip (surface) mining or underground mining methods. The chief coal fields of the United States are the Appalachian (from N Pennsylvania into Alabama), the Eastern Interior (Illinois, Kentucky, and Indiana), the Northern Interior (Michigan), the Western Interior (Iowa, Kansas, Missouri, Oklahoma, and Arkansas), the Rocky Mountain (Colorado, Wyoming, Utah, New Mexico, Montana, and North Dakota), the Pacific (Washington), and the Gulf Coast (Texas, Arkansas, and Louisiana). In Europe the chief coal-producing countries are Russia, Ukraine, Germany, Great Britain, Poland, France, and Belgium. There are valuable coal fields in China, Siberia, India, South Africa, and Australia, but few in South America. |
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