School of Earth & Environmental Sciences
Williams, M P., Formation processes and context of complex stratigraphic features at the MSA archaeological sites of Pinnacle Point Site 5-6 and Mertenhof during MIS 3 in southern Africa, BSci Hons, School of Earth & Environmental Sciences, University of Wollongong, 2017.
The Middle Stone Age (MSA) is a crucial time period for the understanding of the origins and development of modern human behaviour and their expansion out of Africa into the rest of the world. There are numerous models that strive to explain the emergence of behavioural modernity, however these are inhibited by weak or poorly resolved evidence for modern human behaviour and occupation of many key MSA sites during Marine Isotope Stage 3 (MIS3).
Pinnacle Point Site PP5-6 (PP5-6) and Mertenhof Rock Shelter (MRS) are two MSA sites with rich evidence of modern human occupation during the MSA. These two sites contain complex stratigraphic features. Understanding the sedimentary context of these features, and their formation processes will provide a better understanding of human occupation of these sites during MIS 3, and provide a means for conducting similar analysis at other MSA sites.
Optical dating of single quartz grains was conducted at both sites, to provide chronological scaffolds for both the complex sedimentary features, and the evidence of modern human occupations during MIS 3 and into the Later Stone Age (LSA). Sediment analysis and geological observations of the sedimentary contacts were also conducted to better understand formation processes of specific stratigraphic features. These methods were used to create and test different hypotheses for formation of these complex features.
A total of 13 optical ages were obtained from the two sites. These were placed within their stratigraphic contexts to determine how and when the complex stratigraphic features were deposited in relation to surrounding archaeological stratigraphy.
The ages provided meaningful results for determining modern human occupation of MRS between ~51 ka and 22 ka ago, when compared to the artefact evidence contained within the stratigraphy where the optical ages were taken. In southern Africa this is the period that falls after the precocious complexity of the Howiesons Poort and Still Bay and before the appearance of the LSA. At PP5-6, the optical ages provided evidence of modern human occupation between ~31–21 ka. Further studies are required to better understand when the complex stratigraphic feature occurred at PP5-6. These ages, and the lack of mixing associated with them demonstrate occupation of these sites during the crucial later phases of MIS 3, and provide a temporal framework within which the archaeological material they contain can be interrogated. The data provided in this thesis can now be integrated into full site stratigraphy for an improved understanding of the site formation processes at both sites.