The significance of hiatal surfaces in coal seams

A widespread misconception is that coals correspond to single palaeo-peat bodies, which represent continuous and time-invariant records of peat accumulation. Evidence for the occurrence of intra-seam hiatal surfaces within datasets from bituminous coals, lignites and modern peats suggests that existing depositional models for peat and coal require modification. Recognition that coals may represent a succession of stacked mires separated by hiatal surfaces has implications for palaeoenvironmental and sequence stratigraphic studies that assume a continuous record of peat accumulation, as well as for the prediction of whole-seam composition and thickness trends.