The Western Free State Panfield: A Landscape of Myriad Pans and Lunettes

Abstract

The descriptor Western Free State Panfield covers the greatest concentration of pans in southern Africa. Many Free State pans boast fringing lunette dunes on their southern and south-eastern margins. Lunettes derive their name from their sickle-moon shape, yet the environmental requirements which promote and sustain the formation of pan-lunette sequences are still not fully understood. In the western Free State, pans form almost exclusively on the shale substrate of the Ecca Group, suggesting a significant measure of geological control. An apparent pattern of pan orientation exists in agreement with palaeodrainage lines. This supports the notion of bedrock influence on drainage, with drainage in turn playing a direct role in pan formation. Lithological (rock type) control on the formation of pans in the western Free State is, clearly, important. This chapter describes the morphology of pans and lunettes (the two features should, arguably, not be separated) and reviews the origins of their formation. Finally, pans as a resource are examined, and their significance as a key element of the Free State landscape and a proxy for environmental change is assessed.