where is coal found and how is it formed
Coal
Coal is a combustible black or brownish - black sedimentary rock usually occurring in rock strata in layers or veins called coal beds or coal seams . The harder forms , such as anthracite coal , can be regarded as metamorphic rock because of later exposure to elevated temperature and pressure . Coal is composed primarily of carbon , along with variable quantities of other elements , chiefly hydrogen , sulfur , oxygen , and nitrogen . Coal is a fossil fuel that forms when dead plant matter is converted into peat , which in turn is converted into lignite , then sub-bituminous coal , after that bituminous coal , and lastly anthracite . This involves biological and geological processes . The geological processes take place over millions of years . 
Coal is a combustible black or brownish - black sedimentary rock usually occurring in rock strata in layers or veins called coal beds or coal seams . The harder forms , such as anthracite coal , can be regarded as metamorphic rock because of later exposure to elevated temperature and pressure . Coal is composed primarily of carbon , along with variable quantities of other elements , chiefly hydrogen , sulfur , oxygen , and nitrogen . Coal is a fossil fuel that forms when dead plant matter is converted into peat , which in turn is converted into lignite , then sub-bituminous coal , after that bituminous coal , and lastly anthracite . This involves biological and geological processes . The geological processes take place over millions of years .
Coal is a combustible black or brownish - black sedimentary rock usually occurring in rock strata in layers or veins called coal beds or coal seams , and it is a fossil fuel that forms when dead plant matter is converted into peat , which in turn is converted into lignite , then sub-bituminous coal , after that bituminous coal , and lastly anthracite .
Coal is a combustible black or brownish - black sedimentary rock usually occurring in rock strata in layers or veins called coal beds or coal seams . Coal is a fossil fuel that forms when dead plant matter is converted into peat , which in turn is converted into lignite , then sub-bituminous coal , after that bituminous coal , and lastly anthracite .
Coal is a combustible black or brownish - black sedimentary rock usually occurring in rock strata in layers or veins called coal beds or coal seams. It is a fossil fuel that forms when dead plant matter is converted into peat, which in turn is converted into lignite, then sub-bituminous coal, bituminous coal and lastly anthracite.
Coal is a combustible black or brownish - black sedimentary rock usually occurring in rock strata in layers or veins called coal beds or coal seams . Coal is a fossil fuel that forms when dead plant matter is converted into peat , which in turn is converted into lignite , then sub-bituminous coal , after that bituminous coal , and lastly anthracite .