Diamictites and associated glacigenic rocks of the Tshidzi Formation represent the Permo-Carboniferous Dwyka Group (Karoo Supergroup) in the Karoo-age basins, i.e. Tshipise, Tuli, northern Lebombo, Ellisras and Springbok Flats, that are situated north of the main Karoo Basin of South Africa. This lowermost Karoo unit represents the onset and development of the Permo-Carboniferous glaciation and the dynamics of the ice sheets in this part of southern Gondwana in the Late Palaeozoic. The highly variable and limited thickness of the Tshidzi Formation suggests preservation in localized depressions of a highly uneven pre-Karoo landscape that was sculpted by southwest moving continental glaciers. All Permo-Carboniferous diamictites and associated glacigenic rocks of South Africa that are preserved north of the main Karoo Basin are now termed Tshidzi Formation due to their similar diagnostic, lithological characters and stratigraphic position. The unit is considered a stratigraphic equivalent of the upper Palaeozoic glacigenic fluvio-lacustrine deposits of the Dukwi Formations in the Kalahari-Karoo Basin of Botswana and Dwyka Group in the Save Basin of southeastern Zimbabwe.