The Cenozoic history of the coastal landscape of the southern Cape province, South Africa: A review

Abstract

We discuss the latest viewpoints and the problems involved in reconstructing the Cenozoic history of the southern Cape coastal landscape based on planation levels, evidence of sea-level fluctuations, plateau clays and fluvial deposits, silcretes and coastal sequences (limestones, lignites and cover sands). We propose a tentative chronology of the Cenozoic history of the southern Cape. Controversy still surrounds the development of the coastal platform, there being two schools of thought. The upper erosion surface is an early to mid-Tertiary peneplain preserved by a ferricrete and silcrete cuirasse. Surficial boulder beds, gravels, sands and clays attest to extensive fluvial action on the proto-coastal forelands. A combination of residual and transported material seems the best explanation of the origins of the weathered clays on the coastal platform. The recent (Pleistocene to Holocene) sand cordons onshore and offshore in the Wilderness embayment exhibit a regular spatial and temporal pattern. Together with the older sands covering the coastal plateau six phases of development have been identified. The interpretation of the Knysna Formation of sands, clays, and lignites is still uncertain. The lignite beds are probably the key to understanding the stratigraphy of the whole region.