Coastal eolian sands, paleosols, and Pleistocene geoarchaeology of the Southwestern Cape, South Africa

Narratives of Pleistocene prehistory for MIS 4 to 9 are primarily constructed on the basis of what appear to be subcontinuous archaeological records in cave sites, with subsidiary geo- and bioarchaeological research attempting to determine the nature of external environments and biotic resources from the inside, rather than the outside. The present study seeks to establish a detailed chronostratigraphy for faunal and archaeological sites linked with coastal sediments in the Southwestern Cape province. Accelerated shore deflation during glacio-eustatic oscillations of sea level deposited multiple eolianites, and textural changes of such calcified sands identify both transgressive and regressive sea level trends. These provide a proxy for local shore proximity, sometimes directly linked to ‘high’ sea level stands. Such sediments are subdivided into lithostratigraphic sequences by multiple paleosols, that range from ABC-soils to calcretes or plinthite/ferricrete horizons. Repeated intervals of solution or karstic activity created underground cavities that allowed fossil bone to collect in or below hyena lairs. Such fills further connect sedimentary units with pedogenic events, to integrate local stratigraphies into a regional lithostratigraphy that can be readily correlated with global chronostratigraphies (MIS stages and Dansgaard-Oeschger events), derived from polar ice and deep sea cores, as well as long stalagmite and pollen records. The faunal assemblages (see Table 9) of MIS 5 and early 4 were penecontemporaneous with pedogenic phases that record greater moisture during intervals when sea level oscillated a little below that of today. Dominated by larger grazers, such assemblages argue for a more open environment than the modern fynbos (sclerophyllous heath/brush) and specifically a land cover of higher productivity and nutritional status. Such conditions probably affected only a fraction of MIS 5 time. Middle Stone Age (MSA) assemblages are limited to late MIS 4 cave/overhang sites, also linked to such pedogenic phases, although an MSA-like site dates to MIS 5d. Older littoral sands, modified by plinthite development, include the Acheulian and faunal site of Duinefontein 2 that may represent MIS 9. Visible evidence for human occupation (including cave/overhang sites) during MIS 4 to 9 (see Table 9) was strikingly discontinuous in the Southwestern Cape begging questions about the number of prehistoric groups, demography, spatial patterning, and ecological context.