PhD Abstract

It has been proposed that the southernmost coast of South Africa was a uniquely important region in later human evolution, in part due to the abundance of nutritious and dense coastal resources. Yet, strong contrasts between its Middle Stone Age (MSA) and subsequent Later Stone Age (LSA) archaeological records cast uncertainty on the significance of shellfish utilisation for processes of human evolution. Furthermore, climatic shifts are frequently advanced as drivers of widespread technological change, but few climate proxy records correspond adequately to the archaeological evidence at a temporal or spatial level to allow them to be unambiguously linked to human cultural activity. This thesis presents a temporally and spatially distributed record of near-shore seasonal sea surface temperatures (SSTs) from serial δO shell measurements of archaeological Turbo sarmaticus opercula. In addition, the annual timing of shellfish harvesting captured in the temperature signal of the shells’ final few growth increments is indicative of hunter-gatherers’ scheduling of foraging behaviours and of their social organisation. A non-destructive method for evaluating the preservation of the original aragonitic shell carbonate using Fourier transform infrared spectrometry with an attenuated reflectance attachment is presented, allowing for robust SST reconstructions. Near-shore SST reconstructions are presented from the LSA levels of Nelson Bay Cave and Byneskranskop 1, along with new radiocarbon chronologies spanning the terminal Pleistocene and the Holocene, and from the MSA deposits at Pinnacle Point 5–6 and Klasies River Main site, dated to periods in Marine Isotope Stage (MIS) 5 and across the MIS5/4 transition. These reconstructions confirm the utility of near-shore SST records for terrestrial climate reconstructions, indicating shifts in summer rainfall during the Holocene and across MIS5/4. The annual timing of shellfish foraging is shown to be markedly different between the MSA and LSA, permitting more nuanced assessments of foraging behaviours within the MSA and LSA.