African Middle Stone Age Sites Research Articles

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.

Language and human evolution

Abstract The fossil indications for speech, inferred from skull endocasts and from the anatomy of the vocal tract, the vertebral column, and the bony ear, suggest that there was a grade shift from the australopiths ( Australopithecus and Paranthropus ), who lived mainly before two Ma (million years ago), to species of Homo , who lived mainly afterwards. The australopiths were probably no more capable of speech than living chimpanzees are, but bones suggest that all fossil species of Homo anticipated living humans in their speech ability. The oldest well-documented stone tools, assigned to the Oldowan Tradition between 2.6 and 1.76 Ma, required a sophisticated understanding of how to produce sharp-edged flakes routinely. Verbal instruction, albeit at a rudimentary level, was probably required to transmit this understanding between individuals and from generation to generation. More complex, though still primitive forms of language were likely linked to post-Oldowan technological advances, including the appearance of the Acheulean Tradition, defined by hand axes and other shaped stone tools 1.76 Ma, the addition of more refined hand axes to the Acheulean Tradition 1–0.7 Ma, and finally the abandonment of hand axes in favor of a wide variety of flake tools, probably often mounted on wooden handles, in the African Middle Stone Age and west Eurasian Middle Paleolithic beginning 300–250 ka (thousands of years ago). Putative art objects and personal ornaments that occasionally occur in African Middle Stone Age sites between 100 and 60 ka may imply “symbolism”, intimately connected to language historically, but if the limited archaeological evidence is accepted, it implies a form of symbolism that was qualitatively different from the unambiguous historical variety. The historical kind, marked by indisputable art and personal ornaments, appeared only 50–40 ka, which suggests this was also when full-fledged language appeared. The abrupt appearance of language and other fully modern cognitive traits 50–40 ka surely occurred in Africa, and enhanced cognition is likely to explain the nearly simultaneous expansion of fully modern Africans to Eurasia, where they replaced or swamped the Neanderthals and other non-modern humans. Ancient DNA could be used to test the idea that fully featured language appeared about 50 ka, if it becomes possible to determine whether the Neanderthals and other non-modern humans lacked some genes that underpin language and other cognitive functions in all living people.

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.

Quantification of climate and vegetation from southern African Middle Stone Age sites – an application using Late Pleistocene plant material from Sibudu, South Africa

In southern Africa numerous Middle Stone Age (MSA) sites document important steps in technological and behavioural development leading to significant changes in the lifeways of modern humans. To assess whether these cultural changes and developments may be related to environmental changes we need to ascertain past environments. To do this we apply a new quantitative method, the GIS-based Coexistence Approach (CAGIS), on fossil plant material from the MSA site Sibudu, KwaZulu-Natal, South Africa. Previous qualitative environmental interpretations of the fossil fauna and flora of the site remain ambiguous. Because much of the material is anthropogenically introduced, it is difficult to distinguish between the effects of natural changes in the local vegetation and behavioural changes of the people that inhabited the shelter. CAGIS can be applied to such biased assemblages and seems to be an adequate method to directly quantify palaeoclimate and vegetation parameters at an archaeological site.The CAGIS analysis shows that during the Howiesons Poort (HP) Industry winters were slightly colder and drier than present, whereas during summer, temperatures and precipitation were similar to today. Post-HP winters were drier and colder than present, presumably colder than during the HP. Summer temperatures remained the same, but summer precipitation decreased from the HP to post-HP. Vegetation cover was less than today, may be even less than during the HP. The late MSA was observably warmer than the older periods, especially during winter. At the same time summer precipitation slightly increased and vegetation became more dense, but still remained generally open similar to today's anthropogenic landscape.Generally, climatic changes are most pronouncedly reflected in winter temperature parameters, especially in minimum winter temperatures, and to a lesser extent by changes in summer precipitation. The observed ecological trends seem to be affected mainly by variations through time in winter temperatures. This refinement of interpretation was not discernible using previous methods for analysing the Sibudu data.

The accumulation of Stone Age lithic artifacts in rock fragment mulches in northern Ethiopia

AbstractLithic artifacts buried in the soil profile may be transported to the surface during tillage‐induced kinetic sieving, differential erosion, or swell–shrink cycles of clays and become part of a rock fragment mulch. Archaeologically, these manifestations are recognized as surface scatters. Although artifacts at the soil surface are difficult to relate to the local stratigraphic context, surface assemblages may provide information on lithic industries and the archaeological significance of sparsely explored regions. Through in situ investigation of surface material in 60 1 × 1 m2 plots in the Tembien district in the northern Ethiopian highlands, we show that rock fragment mulches can contain a significant number of lithic artifacts and we provide evidence for mid‐Pleistocene occupation of a site. Considering that severe rill and gully erosion may be a threat to the archaeological heritage and that well‐dated African Middle Stone Age sites are rare, we conclude that the region deserves more attention for archaeological research. © 2009 Wiley Periodicals, Inc.

An early bone tool industry from the Middle Stone Age at Blombos Cave, South Africa: implications for the origins of modern human behaviour, symbolism and language

Twenty-eight bone tools were recovered in situ from ca. 70ka year old Middle Stone Age levels at Blombos Cave between 1992 and 2000. These tools are securely provenienced and are the largest collection to come from a single African Middle Stone Age site. Detailed analyses show that tool production methods follow a sequence of deliberate technical choices starting with blank production, the use of various shaping methods and the final finishing of the artefact to produce “awls” and “projectile points”. Tool production processes in the Middle Stone Age at Blombos Cave conform to generally accepted descriptions of “formal” techniques of bone tool manufacture. Comparisons with similar bone tools from the Later Stone Age at Blombos Cave, other Cape sites and ethnographic collections show that although shaping methods are different, the planning and execution of bone tool manufacture in the Middle Stone Age is consistent with that in the late Holocene.The bone tool collection from Blombos Cave is remarkable because bone tools are rarely found in African Middle or Later Stone Age sites before ca.25ka. Scarcity of early bone tools is cited as one strand of evidence supporting models for nonmodern behaviour linked to a lack of modern technological or cognitive capacity before ca.50ka. Bone artefacts are a regular feature in European sites after ca.40ka, are closely associated with the arrival of anatomically modern humans and are a key behavioural marker of the Upper Palaeolithic “symbolic explosion” linked to the evolution of modern behaviour.Taken together with recent finds from Klasies River, Katanda and other African Middle Stone Age sites the Blombos Cave evidence for formal bone working, deliberate engraving on ochre, production of finely made bifacial points and sophisticated subsistence strategies is turning the tide in favour of models positing behavioural modernity in Africa at a time far earlier than previously accepted.