Lithostratigraphy of the late Cenozoic Maputaland Group

The KwaZulu-Natal coastal zone and the Maputaland coastal plain in the extreme north of the province are underlain by a succession of littoral marine deposits related to coastal processes influenced by glacio-eustatic sea-level fluctuations and epeirogenic uplift during the period from the mid Miocene to the Holocene. These unconsolidated or calcite-cemented sediments have been the subject of various lithostratigraphic classifications, but representation of the units on published geological maps has been inconsistent (Geological Survey, 1975, 1985, 1987, 1988). This is mainly due to the deep weathering of the rocks, poor outcrop and weakly defined geochronological framework for the range of sedimentary deposits. The Maputaland Group (Botha, 1997) was defined through the interaction of members of the SACS Cenozoic Task Group and drew upon the criteria used to characterise and sub-divide similar rocks and unconsolidated sediments on the Eastern Cape coast (Algoa Group; le Roux, 1990) and the southern Cape coast (Bredasdorp Group; Malan, 1989). In most cases direct correlation at the Formation level is possible between these lithostratigraphic groupings. Recent improvements to the chronological framework as a result of cosmogenic isotope burial dating of the Pliocene littoral marine deposits and luminescence dating techniques applied to late middle Pleistocene to Holocene unconsolidated dune sands, have supported the differentiation of similar sedimentary units and inter-regional correlation.