South African Middle Stone Age Research Articles

Technological and geometric morphometric analysis of ‘post-Howiesons Poort points’ from Border Cave, KwaZulu-Natal, South Africa

Lithic assemblages immediately following the Howiesons Poort, often loosely referred to as the ‘post-Howiesons Poort’ or MSA III, have attracted relatively little attention when compared to other well-known phases of the South African Middle Stone Age (MSA) sequence. Current evidence from sites occurring in widely-differing environments suggests that these assemblages are marked by temporal and technological variability, with few features in common other than the presence of unifacial points. Here we present a technological and geometric morphometric analysis of ‘points’ from the new excavations of Members 2 BS, 2 WA and the top of 3 BS members at Border Cave, KwaZulu-Natal, one of the key sites for studying modern human cultural evolution. Our complementary methodologies demonstrate that, at this site, hominins adopted a knapping strategy that primarily produced non-standardised unretouched points. Triangular morphologies were manufactured using a variety of reduction strategies, of which the discoidal and Levallois recurrent centripetal methods produced distinctive morphologies. We find technological and morphological variability increases throughout the post-Howiesons Poort sequence, with clear differences between and within chrono-stratigraphic groups. Finally, we assess the suitability of the ‘Sibudan’ cultural-technological typology proposed for post-Howiesons Poort assemblages at Sibhudu, another KwaZulu-Natal site, and find similarities in the morphological axes characterising the samples, despite differences in the shaping strategies adopted. Overall, our work contributes to the growing body of research that is helping to address historical research biases that have slanted our understanding of cultural evolution during the MSA of southern Africa towards the Still Bay and Howiesons Poort technocomplexes.

Heat treatment significantly increases the sharpness of silcrete stone tools

Humans were regularly heat‐treating stone tool raw materials as early as 130,000 years ago. The late Middle Stone Age (MSA) and Late Stone Age (LSA) of South Africa's Western Cape region provides some of the earliest and most pervasive archaeological evidence for this behaviour. While archaeologists are beginning to understand the flaking implications of raw material heat treatment, its potential functional benefits remain unanswered. Using silcrete from the Western Cape region, we investigate the impact of heat treatment on stone tool cutting performance. We quantify the sharpness of silcrete in its natural, unheated form, before comparing it with silcrete heated in three different conditions. Results show that heat‐treated silcrete can be significantly sharper than unheated alternatives, with cutting forces halving and energy requirements reducing by approximately two‐thirds. The data suggest that silcrete may have been heat treated during the South African MSA and LSA to increase the sharpness and performance of stone cutting edges. This early example of material engineering has implications for understanding Stone Age populations’ technological capabilities, inventiveness and raw material choices. We predict that heat‐treatment behaviours in other prehistoric and ethnographic contexts may also be linked to increases in edge sharpness and concerns about functional performance.

Breakage, scarring, scratches and explosions: understanding impact trace formation on quartz

Quartz projectiles have received attention in the recent years due to, for instance, their discovery at prominent South African Middle Stone Age sites. However, very few methodological studies have been dedicated to quartz armatures and the ones published so far are not built on an understanding of the particular behaviour of quartz under mechanical stress. Here, we investigate impact damage formation on automorphic and xenomorphic quartz (crystal quartz and vein quartz) through the microscopic analysis of 91 experimental armatures using a combination of low and high magnifications and SEM. Our results show that the structural properties of quartz affect the attributes of impact breaks and other damage. We also examine wear patterns on three different types of projectiles and offer preliminary guidelines for identifying them in archaeological assemblages. We argue that while quartz assemblages withhold significant potential for understanding past hunting technologies, the methods used for identifying and interpreting quartz projectiles need to be adjusted so that they take into account the notable differences between the macrocrystalline and cryptocrystalline varieties of this raw material.

Stable isotope evidence for (mostly) stable local environments during the South African Middle Stone Age from Sibudu, KwaZulu-Natal

Site-specific environmental and climatic records are crucial to our understanding of human behavior and cognition during the African Middle Stone Age. This is particularly true of the South African Middle Stone Age record with its enigmatic and relatively short lived Still Bay and Howieson's Poort industries. Existing environmental models for the South African Middle Stone Age are primarily contingent on global climatic data which are temporally, spatially, and/or stratigraphically separated from archaeological sites. The well-dated and extensive Middle Stone Age sequence of Sibudu provides a rare opportunity to gather the high-resolution on-site data which are sorely needed to evaluate behavior-environment links ‘on the ground.’ Stable carbon and oxygen isotope data were collected from faunal tooth enamel samples spanning the entire Sibudu sequence excavated by Wadley from >77 to ∼38 thousand years ago (ka). Two periods of habitat change are identified at Sibudu. The pre-Still Bay (>73 ka) is characterized by more closed, likely forested, and mesic conditions than the rest of the sequence. Late and final Middle Stone Age industries (∼48–38 ka) at Sibudu are associated with more open and likely drier conditions than earlier. No major environmental or habitat changes based on stable isotope data, however, are identified in the Sibudu record concordant with the Still Bay, Howieson's Poort, or post-Howieson's Poort techno-complexes. These results suggest that social and demographic changes were presumably as significant as environmental conditions, if not more so, in behavioral transitions at Sibudu.

Is early silcrete heat treatment a new behavioural proxy in the Middle Stone Age?

The South African Middle Stone Age (MSA) has in recent years become increasingly important for our understanding of the emergence of ‘modern human behaviours’. Several key innovations appeared in this context for the first time, significantly pre-dating their re-invention in the European Upper Palaeolithic. One of these innovations was heat treatment of stone to improve its quality for the production of stone tools. Heat treatment may even be the oldest well-documented technique used to intentionally alter the properties of materials in general. It is commonly thought of as requiring the skilled use of fire, a high degree of planning depth and complex cognitive abilities. However, to work on these fundamental concepts we need to analyse the techniques and procedures used to heat-treat and we need to understand what they imply. In this paper, we present a direct and expedient comparison between the technical complexities of four alternative heat treatment procedures by coding the behaviours required for their set-up in so-called cognigrams, a relatively new method for understanding complexity based on the problem-solution distance. Our results show that although the techniques significantly differ in complexity, the techniques used in the MSA fall within the range of complexities known from other MSA techniques. Heat treatment in above-ground fires, as it was practised during this period in South Africa, was even one of the most complex techniques at the time of its invention. Early heat treatment can therefore be considered an important behavioural proxy that may shed light on the behaviour and socioeconomic structure of past groups. The implications of this are highlighted by the ongoing debate about ‘modernity’, ‘behavioural flexibility’ and ‘complex cognition’ of early anatomically modern humans in Africa.

Identifying early modern human ecological niche expansions and associated cultural dynamics in the South African Middle Stone Age

The archaeological record shows that typically human cultural traits emerged at different times, in different parts of the world, and among different hominin taxa. This pattern suggests that their emergence is the outcome of complex and nonlinear evolutionary trajectories, influenced by environmental, demographic, and social factors, that need to be understood and traced at regional scales. The application of predictive algorithms using archaeological and paleoenvironmental data allows one to estimate the ecological niches occupied by past human populations and identify niche changes through time, thus providing the possibility of investigating relationships between cultural innovations and possible niche shifts. By using such methods to examine two key southern Africa archaeological cultures, the Still Bay [76–71 thousand years before present (ka)] and the Howiesons Poort (HP; 66–59 ka), we identify a niche shift characterized by a significant expansion in the breadth of the HP ecological niche. This expansion is coincident with aridification occurring across Marine Isotope Stage 4 (ca. 72–60 ka) and especially pronounced at 60 ka. We argue that this niche shift was made possible by the development of a flexible technological system, reliant on composite tools and cultural transmission strategies based more on “product copying” rather than “process copying.” These results counter the one niche/one human taxon equation. They indicate that what makes our cultures, and probably the cultures of other members of our lineage, unique is their flexibility and ability to produce innovations that allow a population to shift its ecological niche.

Tempering-residue on heat-treated silcrete: an experimental perspective and a potential analytical protocol

Silcrete heat treatment in the South African Middle Stone Age has been understood as a proxy for several key concepts in the evolution of early anatomically modern humans, although relatively little is yet known about the techniques and procedures used for it. Tempering-residue on heat-treated artefacts is one of the few known proxies for such a heating technique. It was reported to indicate heat treatment in open-air fires rather than in a sand-bath. There are however, several questions that need to be answered before tempering-residue can be used as an unambiguous proxy for heat treatment in open-air fires. These questions included: does it exclusively form in contact with embers? Is it only produced by green wood? We investigate the conditions under which tempering-residue forms using an experimental approach and wood from the zone of natural silcrete occurrence in South Africa. Our results confirm earlier publications by highlighting that tempering-residue only forms during heat treatment in direct contact with embers. Moreover, it indicates the use of green (not dried) wood in these fires. We also propose a potentially non-destructive analysis protocol for identifying tempering-residue on silcrete artefacts using infrared and Raman spectroscopy. The implications of these results for our understanding of early stone heat treatment and Middle Stone Age archaeology in general are highlighted by the ongoing debate about technical complexity, required investment and modern behaviours of early Homo sapiens.

The ‘Sand-Bath’ and Lithic Heat Treatment in the South African Middle Stone Age: Myth or Reality?

When heat treatment of silcrete for stone knapping was first discovered in the South African Middle Stone Age (MSA), the procedure used for it was suggested to be similar to the one used for heat treatment of finer rocks in other parts of the world: slow sand-bath heating. This comparison may have been based on published data from the fields of ethnography, experimentation and archaeology, describing sand-bath like structures and processes. In this review, I discuss whether the available data from these three fields indeed justify the suggestions that sand-bath heating was used in the context of MSA silcrete heat treatment. A careful revaluation of the available data shows that, although sand-bath heating is a widely accepted procedure that is documented in other parts of the world, understanding the earliest known cases of heat treatment in the MSA calls for another technical procedure.

Landscape variability in tool-use and edge damage formation in South African Middle Stone Age lithic assemblages

Landscape variability in tool-use and edge damage formation in South African Middle Stone Age lithic assemblages

Implications of Nubian-Like Core Reduction Systems in Southern Africa for the Identification of Early Modern Human Dispersals.

Lithic technologies have been used to trace dispersals of early human populations within and beyond Africa. Convergence in lithic systems has the potential to confound such interpretations, implying connections between unrelated groups. Due to their reductive nature, stone artefacts are unusually prone to this chance appearance of similar forms in unrelated populations. Here we present data from the South African Middle Stone Age sites Uitpanskraal 7 and Mertenhof suggesting that Nubian core reduction systems associated with Late Pleistocene populations in North Africa and potentially with early human migrations out of Africa in MIS 5 also occur in southern Africa during early MIS 3 and with no clear connection to the North African occurrence. The timing and spatial distribution of their appearance in southern and northern Africa implies technological convergence, rather than diffusion or dispersal. While lithic technologies can be a critical guide to human population flux, their utility in tracing early human dispersals at large spatial and temporal scales with stone artefact types remains questionable.

Testing a taphonomic predictive model of edge damage formation with Middle Stone Age points from Pinnacle Point Cave 13B and Die Kelders Cave 1, South Africa

The interpretation of taphonomic and behavioral lithic edge wear formation is complicated by equifinality of edge damage morphologies. Rejecting hypotheses that edge damage originates from taphonomic processes is standard practice for many archaeological analyses and should be incorporated into lithic use-wear more explicitly. Quantitative hypothesis testing is advocated here, and facilitated by recording edge wear observations in an image referenced GIS spatial environment. A taphonomic predictive model was generated using trampling and flint-knapping experiments. Trampling experiments were conducted to determine how edge damage is distributed along tool edges due to non-use related, taphonomic processes. Experiments designed to test the assumption that undisturbed flakes do not preferentially orient either surface side-up (dorsal or ventral) were performed. Furthermore, it is argued that artifact orientation data, if available, can also be used to assess whether the frequency of edge damage is correlated with the degree of disturbance. This taphonomic predictive model is then statistically compared with frequency and distribution edge damage data from two South African Middle Stone Age sites. The research presented here illustrates the usefulness of edge damage distribution analysis for accounting for taphonomic processes as causal agents of edge damage formation, and strengthening behavioral interpretations regarding tool function. Bringing tool wear observations into a uniform spatial structure is one avenue for standardization of lithic use-wear analysis.

Digital imaging technology and experimental archeology: a methodological framework for the identification and interpretation of fire modified rock (FMR)

This paper presents the results of a series of experiments for the identification and analysis of fire modified rock (FMR). FMR is a common but frequently overlooked artifact type. Experiments were conducted simulating the effects of different hypothetical burning scenarios on rocks similar to those found in a South African Middle Stone Age site. A digital imaging method was then used to quantify FMR color values, designed to limit intra-analyst bias. Statistical tests and a blind test suggest that unburned rocks and experimental FMR can be separated statistically based on physical appearance. Two burning scenario models, based on measured experimental data were applied to archaeological FMR from a South African Middle Stone Age site named Pinnacle Point 5-6 (PP5-6) and show that the archaeological samples are not statistically different from a simulated campfire and possibly a lithic raw material heat-treatment fire.

Heat treatment in the South African Middle Stone Age: temperature induced transformations of silcrete and their technological implications

It was recently found that silcrete raw material was heat-treated during the South African Middle Stone Age (MSA) for altering its flaking properties. This finding led to hypotheses about the implications for the MSA hunter-gatherers such as the cost of thermal treatment in terms of investment and firewood. To date, these hypotheses lack a solid basis, for data on the thermal transformations of South African silcrete and, hence, the necessary heating procedure and heating environment, is missing. In order to produce such data, we conducted an experimental study within the framework of the Diepkloof project. This work is based on the petrographic, mineralogical and structural analysis of South African silcrete from the West Coast and its thermal transformations. Our results shed light on the nature of these transformations, the ideal heating temperatures and the tolerated heating speed. The processes occurring in silcrete are comparable to flint, i.e. the loss of chemically bound ‘water’ and the formation of new Si–O–Si bonds, but their intensity is less pronounced. Effective heating temperatures are significantly higher than for flint and the heating speed tolerated by South African silcrete is relatively fast. These findings imply that silcrete heat treatment cannot be directly compared with flint heat treatment. Unlike flint, heating silcrete does not require the setup of a dedicated heating environment and may have been performed in the same time as other fire related activities. This would represent only a minor supplementary investment in time and firewood. These results have broad implications for the discussion about technological evolution and the acquisition of specialised knowledge in the MSA.

The Exploitation of Plant Resources by Early Homo sapiens: The Phytolith Record from Pinnacle Point 13B Cave, South Africa

The capacity to detect remnants of fire usage in archaeological sites, along with a better understanding of its use by prehistoric populations, can help us to shed light on hominin cognition, social organization, and technology. The application of phytolith studies to understand fire and its use can be widely applicable since plants typically contain phytoliths that are identifiable to different taxonomic levels. Pinnacle Point 13B (PP13B) is one of several South African Middle Stone Age (MSA) sites that shows an abundant presence of lenses of burnt material and intact hearths. Phytolith analyses at PP13B have been used to identify the types of plants used as fuel in the hearths. The phytoliths overall show high levels of alteration, and varying alteration is used to identify areas with higher alkaline conditions related to dripping water. In some areas of the site, there is excellent preservation of multicellular structures from the epidermal leaves of dicotyledonous plants, suggesting in situ structures with practically no chemical or post‐depositional alteration. A notable pattern is the abundance of dicotyledonous leaves from the rear of the cave, which might indicate specific leaf‐fuels for the fires, short‐term fire activities, or other actions such as cooking.

Prey Choice During the South African Middle Stone Age: Avoiding Dangerous Prey or Maximising Returns?

Scrutinising prey choice allows the testing of hypotheses on whether the hunting capabilities of Middle Stone Age (MSA) people were as sophisticated as those of Later Stone Age hunter–gatherers. I apply an optimal foraging perspective to investigate whether MSA prey choice was constrained by the danger associated with hunting certain species. Here, I study the relative importance of elands, buffalo and suids. Eland was the most attractive prey to hunter–gatherers because it is large and docile. Buffalo and suids are more aggressive. When additional species to eland needed to be exploited, we would expect unsophisticated hunters to prefer the smaller suids over buffalo. If hunting prowess was sufficient to deal with both buffalo and suids, buffalo should be preferred. Due to their size, exploitation of buffalo would be more profitable than exploitation of suids. I show that, taking environmental circumstances into account, buffalo were preferred to suids, suggesting that MSA people were capable, sophisticated hunters.

Were snares and traps used in the Middle Stone Age and does it matter? A review and a case study from Sibudu, South Africa

The concept of remote capture involved in the creation and use of snares and traps is one of several indicators that can be used for the recognition of enhanced working memory and complex cognition. It can be argued that this humble technology is a more reliable indicator of complex cognition than encounter hunting, for example with spears. It is difficult to recognize snares and traps archaeologically because they are generally made from materials that do not preserve well. To infer their presence in the past, it is therefore necessary to rely on circumstantial evidence such as mortality profiles, taxonomic diversity and high frequencies of creatures that are susceptible to capture in snares or traps. Clearly there are some problems with using snares to infer complex cognition because people do not necessarily choose meat-getting strategies with the lowest costs. Although snares make economic sense because they reduce search costs, their use by modern hunters is not associated with the type of status accorded to other means of hunting. Social demands, more than economic or environmental ones, may consequently have determined the amount of snaring and trapping that occurred in the past. Because of social attitudes, an absence of snaring need not mean that people were incapable of using this technique. At Sibudu, a South African Middle Stone Age site, snares or other non-selective capture techniques may have been used during the Howiesons Poort and perhaps also the Still Bay Industry. The circumstantial evidence consists of 1. high frequency representations of animals that prefer forested environments, including the tiny blue duiker (adult and juvenile) and the dangerous bushpig, 2. high frequencies of small mammals, 3. high taxonomic diversity and, 4. the presence of small carnivores. Importantly, the Howiesons Poort faunal assemblage is different from that in more recent Middle Stone Age occupations of the site.

Animal exploitation strategies during the South African Middle Stone Age: Howiesons Poort and post-Howiesons Poort fauna from Sibudu Cave

As one of the few sites that preserve fauna from the Howiesons Poort (HP) and the immediately post-HP Middle Stone Age (MSA), Sibudu Cave provides a unique opportunity to explore the range of variability in subsistence behaviors during this important phase in human behavioral evolution. In addition to providing information on subsistence, the faunal assemblage serves as a means of reconstructing the environmental conditions during these two periods. While the HP fauna is dominated by species that prefer closed (particularly forested) habitats, the fauna from the upper-most layers of the post-HP MSA are largely representative of open conditions. These results largely coincide with macrobotanical analyses and may simply indicate that the extent of the riverine forest near the site was greater during the HP. Alternatively, the pattern could be indicative of a marked intensification in the exploitation of the environment in the immediate vicinity of the shelter during the HP, perhaps resulting from a decline in the productivity of adjacent regions. We also document variation in the frequency of the different bovid size classes over time. The evidence shows a declining focus on the smallest bovids after the HP, with a parallel increase in the frequency of large and very large bovids. Beyond a heavy focus on small bovids, small mammals and suids also occur at higher frequencies during the HP. Although the HP faunal assemblage is largely unique as compared to the bulk of the MSA sequence at Sibudu, the evidence presented here suggests that the transition between the HP and the post-HP MSA may have been more gradual than abrupt. Our results indicate that the HP and post-HP MSA inhabitants of Sibudu Cave were capable hunters; however, hunting strategies appear to show marked variation over time. We propose that the variability in animal procurement strategies reflects a degree of behavioral plasticity beyond that generally attributed to MSA populations.

Le mobilier Stillbay et Howiesons Poort de l'abri Diepkloof. La chronologie du Middle Stone Age sud-africain et ses implications

Stillbay and Howiesons Poort stone tool techno-complexes. South African Middle Stone Age chronology and its implications. In the midst of the South African MSA, the Stillbay and Howiesons Poort technological complexes are marked by a set of ‘precocious’ indicators of modern character of the sort that characterize the industries that follow them. Unfortunately, the relative chronology of these two complexes has remained imprecise: both radiometric dates and relevant archaeological sequences are rare. Excavations begun in 1998 in Diepkloof rockshelter (Western Cape) have provieded a sequence in which the Stillbay facies clearly underlies the Howiesons Poort assemblages. In addition, the Diepkloof Howiesons Poort assemblages have now been dated, by thermo-luminescence, to between 55 and 65 ky. To cite this article: J-P. Rigaud et al., C. R. Palevol 5 (2006) .