Palaeoecology of selected South African export coals from the Vryheid Formation, with emphasis on the role of heterosporous lycopods and wildfire derived inertinite☆

The study of six bulk coal samples from the Early Permian Vryheid Formation of the Karoo Basin, South Africa has revealed the importance of wildfire in this coal-forming environment. Inertinite is a major constituent of these coals and was predominantly produced by wildfire. The accumulation of the peat in this setting was both autochthonous and hypautochthonous/allochthonous, conditions varying between the occurrence of standing water and desiccation. Woody gymnosperms and also lycopods were important components of the coal swamp vegetation, of which the diversity and abundance of the lycopods may be tentatively assessed by the distribution of megaspores in the coals. Consistent with lycopod reproductive strategy, these megaspores are more abundant and diverse where the vitrinite content is greater.