A thesis submitted to the Faculty of Science, University of the Witwatersrand, Johannesburg, in fulfilment of the requirements for the degree of Doctor of Philosophy. Johannesburg, 2016. / This study is within the context of the Howiesons Poort Industry of the Middle
Stone Age. This is a dynamic period of increasing behavioural and material
complexity. In the lithic assembles, this can be seen in a strong bias towards the
selection of high-quality fine-grained rocks. This has often been interpreted as
evidence for long distance travel, reciprocal exchange, or even increased mobility.
This study aims to determine what influence the mechanical properties of rock
types exerted on the Middle Stone Age assemblages at Sibudu. This requires a
consideration of the distribution of rock types across the landscape surrounding
Sibudu Cave. The study was limited to hornfels and dolerite as these rock types
dominate the Sibudu assemblage, and quartz and quartzite that were sometimes
used at the site are exceedingly difficult to collect in large enough sample sizes to
conduct experiments. It was important to carry out tests on the mechanical
properties of hornfels and dolerite and to characterise them. Hardness, roughness,
elasticity and brittleness dictate the ease of knapping as well as the durability of
flaked tools and these rock properties can be measured by the mechanical tests
described here. To understand how these properties affect the assemblage in
practice, dolerite and hornfels flakes were produced and used experimentally for
cutting and scraping leather. The edge damage produced was compared. Finally,
preliminary analysis was undertaken of square C4, layer PGS, which forms part of
the oldest Howiesons Poort layer at Sibudu. The information and insights gained
from the mechanical tests and experimental work were used to interpret the role of
mechanical properties for the archaeological sample of PGS.
The results show that all rocks used at Sibudu are local, and do not support any
models of long distance travel/trade, reciprocal exchange, or models of increased
mobility. Dolerite and hornfels form the bulk of the assemblage at all times
(except briefly in the post-Howiesons Poort), and there is a bias towards the
selection of fine-grained rocks during the Howiesons Poort. Dolerite can be
characterised as hard, tough, elastic, and rough, while hornfels is hard, brittle, and
fine-grained. These properties affect knapping and the qualities of a tool’s edge.
The properties of hornfels allow for knapping accuracy and predictability, and it is
better suited to blade production and cutting. However, tool edges are not robust.
Dolerite is not as easy to knap, but produces tools with a robust edge that are
particularly suited to scraping. Each rock type appears to have fulfilled a different
function at Sibudu.
Most rock studies geochemically source rocks, establish models of rock
procurement or show trends in rock selection for artefact classes. Mechanical
studies of rocks have typically formed part of heat treatment debates (Brown et al
2009; Domanski & Webb 1992, 1994; Webb & Domanski 2008). Through the
combined approach of mechanical testing, experimental knapping and tool use,
and lithic analysis, this research provides a context for possible rock procurement
choices at a time in the past when many African sites reveal a changing pattern of
rock selection. / LG2017
| Identifer | oai:union.ndltd.org:netd.ac.za/oai:union.ndltd.org:wits/oai:wiredspace.wits.ac.za:10539/21730 |
| Date | January 2016 |
| Creators | Kempson, Helen |
| Source Sets | South African National ETD Portal |
| Language | English |
| Detected Language | English |
| Type | Thesis |
| Format | Online resource (xiv, 185 leaves), application/pdf, application/pdf |
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