ON THE ORIGIN OF LOW-REFLECTING INERTINITES IN COALS FROM THE HIGHVELD COALFIELD, SOUTH-AFRICA

Three seam profiles from the Highveld Coalfield were analysed for their maceral composition, with special reference to their proportions of vitrinite, low-and high-reflecting inertinite, as well as of massive, detrital and cellular macerals. Distinct cyclic patterns can be delineated, based on the vitrinite content, as well as on the ratios of massive and detrital macerals. The coals consist mainly of detrital macerals and low reflecting inertinite. It is suggested that the coals are hypautochthonous. Thus they initially formed under good preservation conditions resulting in humification and gelification of the major part of the peat. Subsequently the peat was transported and redeposited, so that it was physically disintegrated (resulting in high proportions of detrital macerals) and partly oxidized (resulting in a ratio of low-reflecting inertinite).