An inter-continental comparative study on heat treatment of silcrete raw materials in the South African Middle Stone Age and the Australian Prehistory
Final Report Abstract
Anatomically modern humans evolved in Africa during the Middle Stone Age and immigrated to Australia around 50 000 years ago. Both archaeological records document heat treatment of Silcrete, a high quality raw material common to both regions. Research questions of the present project were: Did the first Australians bring the technology with them or did it locally evolve? Did heat treatment play the same role in Australian tool making as in South Africa? Was it done in the same way? The aim of this research project was to shed light on these questions by studying and comparing heat-treated silcrete from both continents with archaeological and archaeometric techniques. We have obtained results that allow for answering all three posed questions. We found that, while in South Africa heat treatment was practised over a ~100 ka long period with no major changes (around 80% of all silcrete was heated through the South African sequence), in Australia, heat treatment was subject to major changes over time and in different regions. We also found that on both continent, silcrete was heat-treated to facilitate miniaturization and the exhaustion of available raw materials. We also found important arguments that, at least in parts of Australia, silcrete heat treatment was a fast and expedient process that relied on the use of open-air fires. This is the same behaviour as in South Africa, pinpointing an important role of raw materials in the choice and invention of transformative techniques. These results have important implications for our understanding of early pyrotechnology in that they show that different technical solutions may converge into similar techniques over time. The project also provides a starting ground for future projects on Australian heat treatment, as it produced the first systematic dataset on many major early sites across the continent. By investigating the motivations and techniques of hunter-gatherers in two distant environments, the project uncovered some of the fundamental mechanisms that drive invention, re-invention and technical convergence.
Publications
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2018, Heat treatment in the Still Bay - A case study on Hollow Rock Shelter, South Africa, Journal of Archaeological Science: Reports, 21, p. 712-720
Schmidt, P., Högberg, A.
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2018, Is early silcrete heat treatment a new behavioural proxy in the Middle Stone Age?, PLoS ONE, 13, 10, p. e0204705
Stolarczyk, R.E., Schmidt, P.
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2019, Evolution of Silcrete heat treatment in Australia - A regional pattern on the south-east coast and its evolution over the last 25 ka, Journal of Paleolithic Archaeology, 2, 1, p. 74-97
Schmidt, P., Hiscock, P.
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2019, Heat treatment of Kalahari and Cape silcretes: impacts upon silcrete chemistry and implications for geochemical provenancing, Archaeological and Anthropological Sciences, 11, 12, p. 6865–6874
Nash, D.J., Coulson, S., Schmidt, P.
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2019, How reliable is the visual identification of heat treatment on silcrete? A quantitative verification with a new method, Archaeological and Anthropological Sciences, 11, 2, p. 713–726
Schmidt, P.
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2019. Technical innovations during the recent Solutrean in the southwest of France: Recognition of heat treatment of chert and estimation of heating temperatures based on the example of Le Piage (Lot, France), Journal of Archaeological Science: Reports, 27, 102001
Bachellerie, J., Renard, C., Schmidt, P.
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2020, 'Simple' surface-fire heat treatment significantly improves silcrete flake quality and flaking efficiency, Journal of Archaeological Science: Reports, 30, p. 102203
Pargeter, J., Schmidt, P.
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2020, Early silcrete heat treatment in Central Australia: Puritjarra and Kulpi Mara, Archaeological and Anthropological Sciences, 12, Article number: 188
Schmidt, P., Hiscock, P.
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2020, First Results on Understanding the Shiny Surfaces of Heat-Treated Chert, Lithic Technology, 45, 4, p. 240-246
Bachellerie, J., Schmidt, P.
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2020, Heat treatment significantly increases the sharpness of silcrete stone tools, Archaeometry, 06/10/2020
Key, A., Pargeter, J., Schmidt, P.
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2020, The antiquity of Australian silcrete heat treatment: Lake Mungo and the Willandra Lakes, Journal of Human Evolution, 142, Article number: 102744
Schmidt, P., Hiscock, P.
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2020, When was silcrete heat treatment invented in South Africa?, Palgrave Communications, 6, Article number: 73
Schmidt, P., Stynder, D., Conard, N.J., Parkington, J.E.
