Palaeosol nomenclature and classification for South Africa: A new perspective

Abstract

Despite being well renowned for prominent palaeosols, there is no documented attempt at appraising the suitability of existing palaeosol nomenclature and classification systems for palaeosols from South Africa, even in the wake of increasing scientific awareness of the applicability of palaeosol-based proxies for palaeoenvironmental and palaeoclimatic reconstructions. In this study, selected palaeosols from five prominent sites in South Africa were classified using the landmark system of Mack et al. (1993) and the most recent classification system proposed by Krasilinikov and Calderόn (2006). Sequel to field identification and description of the diagnostic horizons, the palaeosols were analysed using routine laboratory procedures for properties including particle size distribution, pH, calcium carbonate content, colour, elemental geochemistry, clay mineralogy and micromorphology for detailed characterisation and classification. The palaeosols qualified as ferric Calsisols, calcic Gleysol, concretionary Argillisol, ochric Calsisol and ochric Protosol using Mack et al. system; and Infracalsisol, Infraluvisol, Infraplinthisol and Infracambisol by Krasilinikov and Calderόn system. Plinthite was quite prominent in the red palaeosol. We, therefore, suggest that another term be coined in the two systems to take care of palaeosols with outstanding preserved plinthic horizons. The complex nature of palaeosols and after burial alterations brings about a lot of changes which would have to be addressed by the international palaeopedology community in order to enhance communication and exchange of knowledge and formulation of relevant theories amongst scientists. Future studies of palaeosol classification in the region would benefit from a more robust and improved unified global classification scheme which would address the loopholes of the existing systems.