Palaeosols on a fluvial terrace at Driekop, Northern Province, South Africa as indicators of climatic changes during the Late Quaternary

A study of an exposed fluvial terrace at Driekop (30 degrees 11'E, 24 degrees 38'S and 800 m above sea level) consisting of palaeosols, Stone Age implements and Iron Age fragments provides indicators of climatic changes during the Late Quaternary. This terrace, at least 12 m thick, with 15 stratigraphic layers (14 of these qualify as palaeosols on the basis of being buried) was analysed according to various methods. Layers were classified according to the diagnostic horizons and properties of the FAO-Unesco system. The genesis of the terrace and layers is ascribed to distinct events including periodicities involving deposition and erosion, as well as various intensities of pedogenesis. Whereas the evidence suggests that the cyclic pattern of erosion and deposition cannot be correlated with climatic changes of the past, it was ascertained that certain soil features (calcareousness, vertic, gleyic, etc.) could provide significant information in this regard. Some of the latter correlations are in agreement with present documented evidence on climatic changes during the Late Quaternary while others are of a contradictory nature. Radiocarbon dates for the calcareous materials, for example, range in age from c. 29.8, 24.1, 12.2 to 4.2 ka and have been regarded as representing conditions drier than present. (C) 1999 INQUA/Elsevier Science Ltd. All rights reserved.