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How coal is formed? |
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Answer» Coal is a combustible black or brownish-black sedimentary rock, FORMED as rock strata CALLED coal seams. Coal is mostly carbon with variable amounts of other elements; chiefly hydrogen, sulfur, oxygen, and nitrogen.[1] Coal is formed when dead plant matter decays into peat and is converted into coal by the heat and PRESSURE of deep burial over millions of years.[2] Vast deposits of coal originate in former wetlands—called coal forests—that covered much of the Earth's TROPICAL land AREAS during the late Carboniferous (Pennsylvanian) and Permian times |
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