Data Sheet No. 5 - The Origin of Coal

Abstract

Publisher Summary This chapter highlights the origin and properties of coal. Coal is a compact, stratified mass of mummified plant debris, interspersed with smaller amounts of inorganic matter and covered by sedimentary rocks The chemical properties of any coal depend upon the proportions of the different chemical components present in the parent plant debris, the nature and extent of the changes that these components have undergone since their deposition, and the nature and quantity of the inorganic matter present. Peat may be considered to be an immature coal and closely resembles, in composition and properties, the most immature of true coals such as young brown coals. The degree of change of chemical composition of a coal, within the series of fossil fuels from peat to anthracite, is known as the rank of that coal. The chapter also discusses different modes of formation of coal-forming deposits. It highlights that in drift origin, the deposition occurs from water of masses of plant debris in shallow basins, lakes, deltas, and estuaries. In situ origin comprises the process in which plants grew and died in the same place, under conditions generally similar to those existing in the formation of modern forest-type peat bogs.