Justin Bradfield

The effects of Class I and II sized bovids on macrofracture formation and tool displacement: Results of a trampling experiment in a southern African Stone Age context

Abstract In this paper we follow from previous experiments that assessed the formation of macrofractures on hunting weapons and trampled tools, and present the results of a new trampling experiment. This new experiment examined the relationship between small bovid trampling and the formation of macrofracture types on replicated stone and bone tools. We also recorded the resulting displacement of the tools in order to assess the relationship between tool morphology and displacement. Three tool types with dimensions similar to southern African archaeological tools were used. The results suggest that small frequencies of certain impact macrofractures occur on tools subject to trampling forces. These frequencies are, however, lower than those generally recorded during hunting experiments. Tool morphologies and fracture combinations are also shown to be important variables in macrofracture analyses. These results contribute to a growing body of experimental data dealing with the relationship between postdepositional processes and macrofracture formation on artifacts.

Macrofractures on bone-tipped arrows: analysis of hunter-gatherer arrows in the Fourie collection from Namibia

Bone points of two types, the one thin and poisoned and the other robust and not poisoned, are examined in this study of impact fractures. The bone points seem to have had similar experiences to stone points, producing fractures of a similar kind. Most of the fractures in the historical collection examined were caused by impacts. However, this early twentieth-century collection is not thought to be representative of contemporary fracture frequencies that occurred in hunting.

Bone Point Functional Diversity: A Cautionary Tale from Southern Africa

In this chapter I present the results of a use-trace study conducted on 357 pointed bone tools from terminal Pleistocene and Holocene assemblages in southern Africa. All the bone points considered here conform to the morphological criteria of projectile arrow heads, as defined by analogy to historic Bushman arrows. Use-wear and residue traces consistent with wood-working and hide processing reveal that not all bone points functioned as projectile armatures in the past. Functional diversity is evident only during the last 6000 years. Bone points from the Pleistocene are routinely subject to rigorous use-wear analyses to establish their function, yet it is often taken for granted that similar tools found in the more recent Holocene were used as projectile tips. This paper cautions against the specious imputation to projectile technology of all bone points based solely on morphometric criteria.

The antiquity of bow-and-arrow technology: evidence from Middle Stone Age layers at Sibudu Cave

Abstract The bow and arrow is thought to be a unique development of our species, signalling higher-level cognitive functioning. How this technology originated and how we identify archaeological evidence for it are subjects of ongoing debate. Recent analysis of the putative bone arrow point from Sibudu Cave in South Africa, dated to 61.7±1.5kya, has provided important new insights. High-resolution CT scanning revealed heat and impact damage in both the Sibudu point and in experimentally produced arrow points. These features suggest that the Sibudu point was first used as an arrowhead for hunting, and afterwards was deposited in a hearth. Our results support the claim that bone weapon tips were used in South African hunting long before the Eurasian Upper Palaeolithic.

Use-Trace Epistemology and the Logic of Inference

Use-trace analyses are regularly used to provide clues about artifact functionality and the use of materials that do not preserve and which are therefore not represented in the archaeological record. While all sciences strive for deductive certainty, they generally make use of inductive and abductive arguments. The same is true of use-trace studies. Here I examine the three main types of logical inference used in archaeological science and the extent to which each one is used in the interpretation of ancient use-traces. Each type of inference provides a different degree of certainty, and it is suggested that use-trace analysts should acknowledge this when presenting the interpretation of their results. Use-traces develop on tools through mechanical processes. They are then used to infer the most appropriate and likely anthropic activity to account for their formation. Despite the appeal to mechanical laws or regularities, the process of imputing anthropogenic activity to these use-traces is abductive and as such carries with it the same logical surety as all abductive inferences.

New Excavations at Border Cave, KwaZulu-Natal, South Africa

ABSTRACT New excavations at Border Cave use high-resolution techniques, including FT-IR, for sediment samples and thin sections of micromorphology blocks from stratigraphy. These show that sediments have different moisture regimes, both spatially and chronologically. The site preserves desiccated grass bedding in multiple layers and they, along with seeds, rhizomes, and charcoal, provide a profile of palaeo-vegetation through time. A bushveld vegetation community is implied before 100,000 years ago. The density of lithics varies considerably through time, with high frequencies occurring before 100,000 years ago where a putative MSA 1/Pietersburg Industry was recovered. The highest percentage frequencies of blades and blade fragments were found here. In Members 1 BS and 1 WA, called Early Later Stone Age by Beaumont, we recovered large flakes from multifacial cores. Local rhyolite was the most common rock used for making stone tools, but siliceous minerals were popular in the upper members.

Identifying the animal species used to manufacture bone arrowheads in South Africa

The identification to species of completely worked bone tools is impossible using standard skeletal morphological markers. Worked bone studies therefore have focused on questions about manufacture and use, rather than on issues of raw material selection strategies. Zooarchaeology by Mass Spectrometry (ZooMS) is a technique that uses unique collagen biomarkers to fingerprint and identify species of origin from small amounts of bone or ivory. We present the first ZooMS analysis of bone arrowheads from southern Africa. Our findings show that a narrower selection of species was selected for tool manufacture than for food, while, at some sites, certain antelope species were selected for tools that are not present in the unmodified faunal remains. We examine what this selectivity might suggest about mechanical suitability and symbolic associations of the species chosen to make tools. We conclude that mechanical suitability was probably of primary concern and that probable symbolic connotations that were attached to certain species did not translate to the technological sphere to the same extent that they did in other parts of the world.

Pointed Bone Tool Technology in Southern Africa. University of Johannesburg, 2014

geoarchaeological studies need to be conducted to resolve the issue. In addition, all the primarily deposited archaeological combustion features in this study were underlain by a basal black layer rich in charcoal, but such layers did not develop in the experimental combustion features and this difference cannot currently be explained. It is thus necessary to conduct more studies of the variables affecting the formation and preservation of combustion features. One aspect to study experimentally is the range of attributes controlling the surface temperatures of campfires. Among the experiments described here, experimental fires burning 5 kg wood produced maximum surface temperatures in the range of 132–848°C, which demonstrates that surface temperatures are unpredictable. The implication is that producing particular temperatures of a fire is not straightforward and that prehistoric fire users needed planning abilities and a thorough knowledge of pyrotechnology. Both these skills require mental abilities like those of modern people and they also require a sophisticated understanding of environmental conditions.