To ensure proper context control for archaeological samples, it is crucial that excavations determine and,where possible, follow the natural stratigraphic subdivisions in a sedimentary sequence.... Show moreTo ensure proper context control for archaeological samples, it is crucial that excavations determine and,where possible, follow the natural stratigraphic subdivisions in a sedimentary sequence. In cases with a single,unchanging source of sedimentary input, this may pose challenges. We present our strategies to deal with a>2 m deep homogeneous Pleistocene stratigraphy at Umhlatuzana rockshelter in South Africa, yieldingarchaeological remains from the Middle Stone Age. The site was originally excavated during a rescue project in 5–10 cm deep artificial spits for lack of visible stratigraphy. We revisited the shelter in 2018 and 2019. We integrate current standard practice such as piece-plotting archaeological materials with digital methods such as cluster analysis and geoarchaeological analyses (e.g., micromorphology, sedimentological analyses, geochemical analyses) to track the different sources of sedimentary input. We also develop an intensive sediment sampling strategy to illuminate geochemical variation within the sequence and postdepositional alterations affecting preservation conditions. We manage to reconstruct a natural stratigraphy of the site combining these methodologies, resulting in a radically changed understanding of the stratigraphy, depositional environment, and mechanisms of postdepositional disturbance. Show less
Schmid, V.C.; Sifogeorgaki, I.; Dusseldorp, G.L.; Chu, W. 2023
Raw materials are the lowest common denominator of any debitage analysis. And yet, the fracture mechanicsof eccentric raw materials are not always fully considered when performing inter-/intra... Show moreRaw materials are the lowest common denominator of any debitage analysis. And yet, the fracture mechanicsof eccentric raw materials are not always fully considered when performing inter-/intra-assemblagecomparisons. The fracture mechanics as one constraint to be respected by the knappers greatly influencearchaeological recovery of debitage products in different raw materials. Thus, our methodologies forrecording debitage morphometrics may need to be adapted to specific raw materials. This means assemblagecomparison and correlation can only be attempted in a context-dependent manner. We review results ofassemblages in both chert and other raw materials from a range of locations across Old World to examinehow such assemblages have been recorded. In doing so, we highlight various pitfalls and limitations, andpropose that it is very important to provide the contextual information and describe exactly what methodwas used and give arguments, why it was used. Show less
We develop a study protocol to efficiently and accurately identify the raw material categories constituting the lithic assemblages at Umhlatuzana rockshelter, South Africa. We combine visual and... Show moreWe develop a study protocol to efficiently and accurately identify the raw material categories constituting the lithic assemblages at Umhlatuzana rockshelter, South Africa. We combine visual and analytical methods to establish a raw material database and to provide a more accurate insight into raw material selection during the Pleistocene Middle and Later Stone Age occupational sequence of Umhlatuzana. The protocol combines petrological properties (as studied on micromorphological samples), elemental composition of the specimens (as measured with p-XRF) and visual characterization by lithic analysts. We tested the protocol by applying it to a sample of piece-plotted lithics from four spits across the stratigraphic sequence. We document the intensive use of sandstone accounting for 25% of the tested sample. We also report a larger importance of hornfels and lower proportion of quartz than was reported in previous analyses (Kaplan 1990). The combination of micromorphological and p-XRF analysis of the Umhlatuzana assemblages demonstrates that with only visual inspection, the variability of raw materials used may be misinterpreted. With accurate raw material datasets, we are better equipped to answer techno-economic questions of the southern African Stone Age. Show less
