PALAEOENVIRONMENTAL CONTROL ON COAL FORMATION, DISTRIBUTION AND QUALITY IN THE PERMIAN VRYHEID FORMATION, EAST WITBANK COALFIELD, SOUTH-AFRICA

The No. 1 and No. 2 coal seams from the Permian Vryheid Formation in the east Witbank Coalfied, South Africa are described with respect to their distribution, thickness and quality. These two coal seams accumulated in a postglacial climatic environment and peat accumulation was closely associated with and influenced by deposition in a braided river system. The fluvial channels that were syndepositional with peat accumulation have resulted in thinning of coal below and above channel axes and pinch-out of coal adjacent to channel margins. A comparison of the Gondwanan Permian peat-forming conditions with those from Carboniferous northern hemisphere counterparts suggests that the differences in coal characteristics between these two regions are probably related to different palaeoclimatic conditions and basin tectonics.