Justin Bradfield | University of Johannesburg, South Africa (original) (raw)

Papers by Justin Bradfield

Azania: Archaeological Research in Africa, 2024

This paper reports the results of a technological and microwear analysis of 110 pieces of worked ... more This paper reports the results of a technological and microwear analysis of 110 pieces of worked bone from the Early Iron Age site of Broederstroom in the Magaliesberg region of South Africa. The results are compared to previous studies of bone tools from the contemporary Later Stone Age sites of Kruger Cave and Jubilee Shelter in an attempt to understand whether the Broederstroom pieces were made locally by the farmers or acquired through trade with hunter-gatherers. Although the bone tool technology at Broederstroom does bear some similarities to the bone material at Kruger Cave, it is quite different from that at Jubilee Shelter. This technological distinction likely indicates that the bone tool industry at Broederstroom is a product of local farmer industry. The usewear results further point to a range of different activities practised by the farmers living at Broederstroom.

Scientific Reports

The detection of complex poison recipes applied to ancient hunting weapons has the potential to p... more The detection of complex poison recipes applied to ancient hunting weapons has the potential to provide important insights into traditional pharmacological knowledge systems. Yet, recipes comprising many ingredients can be challenging to decipher, especially in older samples that have undergone biodegradation. We present the results of our attempt to analyze samples of poison collected from nineteenth and twentieth century arrowheads from southern Africa, and from a 1000-year-old archaeological bone point. The arrow poison residues and reference samples were analyzed by Attenuated Total Reflectance Fourier Transform Infrared Spectroscopy (ATR FTIR) and Gas Chromatography Mass Spectrometry (GC–MS). The ATR FTIR analysis is primarily able to separate between different arrow poison binder recipes. The extractives identified by GC–MS analysis consist of a multitude of components from both binders and active substances, confirming and adding to the results from the ATR FTIR analyses. We ...

Journal of Archaeological Science: Reports

Several taphonomic processes can alter the surface of archaeological bone in a manner that may ca... more Several taphonomic processes can alter the surface of archaeological bone in a manner that may cause them to superficially resemble bone tools used as digging implements. Under close examination, however, the resultant microwear is usually quite distinct. While many experiments have been done to document the effects of fluvial processes on bone surface alteration, there are many mass soil movement process whose microwear effects have not yet been properly investigated and which could conceivably produce microwear similar to digging implements. One example, which pertains to the Cradle of Humankind landscape, is soil creep. We present the results of an experiment that assesses the resultant microwear on stationary bones occasioned by artificially accelerated soil creep processes. We show that the passage of saturated sediments over stationary bones produces rounding and pitting, and does not resemble microwear occasioned either by fluvial transport or experimental digging in sediments. Although there is room to test additional variables, we conclude that the purported bone tools from the Cradle of Humankind sites were not affected by soil creep processes, at least not to the extent that they caused surface alterations.

South African Journal of Science

The chance discovery of a 500-year-old cattle-horn container in a painted rock shelter on the far... more The chance discovery of a 500-year-old cattle-horn container in a painted rock shelter on the farm La vie D’Antan in the Eastern Cape Province of South Africa sheds new light on the antiquity of traditional medicines in the region. We report the micro-residue and GC-MS results of the solidified substance found inside the horn container. Several plant-based medicinal compounds were tentatively identified, of which mono-methyl inositol and lupeol are the most prevalent. Based on pharmacobotanical studies, we suggest the most probable ailments the medicine would have been used to treat and propose the most likely plants from which the ingredients were sourced. Apart from the rock art, whose contemporaneity has not been established, there is no associated archaeology from which to draw specific cultural associations. Although people clearly have been aware of the medicinal properties of plants for at least the last 200 000 years, this is, to our knowledge, the oldest evidence from south...

PLOS ONE

Animal symbolism is a prominent feature of many human societies globally. In some cases, these sy... more Animal symbolism is a prominent feature of many human societies globally. In some cases, these symbolic attributes manifest in the technological domain, influencing the decision to use the bones of certain animals and not others for tool manufacture. In southern Africa, animals feature prominently in the cosmogenic narratives of both hunter-gatherer and Bantu-speaking farmer groups. Whenever these two culturally distinct groups came into contact with each other there would be an assimilation of cosmogenic concepts of power and the adoption of certain symbolically important animals. In this paper, we report on which animals were selected to make bone tools during the first millennium AD contact period in KwaZulu-Natal Province, South Africa, and explore the extent to which this selection may have been influenced by the symbolic associations of specific animals. Our results show selective targeting of specific animals for tool manufacture at some sites, with a narrowing of the range o...

Arheologia

The interpretative potential of microscopic use-wear polishes is a factor of the scale of analysi... more The interpretative potential of microscopic use-wear polishes is a factor of the scale of analysis. Observational surface area decreases in inverse proportion to magnification. In this paper I present the results of polishes on bone tools that have developed from fricative contact with nine different materials. Microwear polish is viewed at five different magnifications. I show that 50x―200x magnification, or observational areas of 0.4―2.0 mm2, is the most appropriate scale of analysis of use-wear polishes regardless of whether one is conducting morphological identifications or relying on surface texture analysis software. The images presented here are meant to serve as an online reference collection to allow use-wear analysts to visualise how polish appearances change at different levels of magnification.

Southern African Field Archaeology

We report on a programme of work to remediate Kruger Cave, a Later Stone Age painted rock shelter... more We report on a programme of work to remediate Kruger Cave, a Later Stone Age painted rock shelter in the western Magaliesberg, South Africa. Kruger Cave, originally excavated in the 1980s and never backfilled or stabilised, has deteriorated through forty years of erosional and quotidian processes that have significantly reduced the extent of the archaeological deposit. The cave is currently occupied by a lay Christian pastor whose activities at the site place the remaining archaeological deposit at further risk. Remedial work was undertaken on what remains of the archaeology-bearing sediment. We also present the preliminary analysis from two small-scale excavations that aimed to document the site’s stratigraphy. We explore the ambivalence of Kruger Cave’s living heritage status within the context of current heritage management practices and discuss how our remedial work is designed to be responsive and respectful to both the archaeological and living heritage priorities.

Journal of Paleolithic Archaeology, 2021

Primate taphonomy in cave deposits is complex, and the taphonomic signatures of different accumul... more Primate taphonomy in cave deposits is complex, and the taphonomic signatures of different accumulation scenarios present some degree of equifinality, rendering their identification in the fossil record challenging. Here, we describe an assemblage of 30 modern chacma baboons, including nine partially mummified individuals, which died inside a cave chamber at Misgrot, South Africa. The mortality profile is attritional, favouring immature and older individuals. We describe skeletal part representation, body postures for the most complete mummies and preserved articulations. Bone surface modifications suggest limited impact by biotic agents besides small rodents and invertebrates. Several specimens were affected by heat-induced damage, most likely resulting from natural combustion of bat guano, abundant on the cave floor. Misgrot has a similar geology and similar dimensions to some Plio-Pleistocene primate-bearing cave deposits from the UNESCO World Heritage Cradle of Humankind area. Implications of the taphonomic features of the Misgrot baboon remains are discussed in the context of some of these fossil assemblages, including the recently discovered Homo naledi assemblages.

Southern African Humanities, 2015

Biochemical analyses of residues preserved on ethno-historical and archaeological artefacts incre... more Biochemical analyses of residues preserved on ethno-historical and archaeological artefacts increase our understanding of past indigenous knowledge systems. The interpretation of biochemical traces is, however, difficult. Problems that can hamper credible interpretations of ethno-historical or archaeological residues include incomplete knowledge about local natural products, limited published data about product applications, and overestimation of the abilities of the analytical techniques to make specific identifications. In an initial attempt to address some of the challenges, we discuss arrow poison as a case in point, and we provide complete, updated inventories of known southern African poison ingedients and recipes, suspected poisons, and the current state of knowledge about these toxins and their effects. We also suggest that discoveries of ancient arrow poison, and the technical steps involved in early toxicology, have the potential to indicate levels of human cognition.

Quaternary Science Reviews, 2020

Quaternary International, 2018

This paper presents the first recognised evidence of bone hoes in South Africa. Two bovine scapul... more This paper presents the first recognised evidence of bone hoes in South Africa. Two bovine scapulae and a portion of a long bone show use-trace evidence that supports our interpretation as ground-working implements. The scapulae were probably hafted onto wooden handles using a combination of plant fibres and sinew, whereas the tool made from the long bone appears not to have been hafted. Bone hoes represent a short-lived technological innovation, although the reasons to account for this remain speculative. The recognition of these agricultural implements poses interesting questions about the extent and variety of bone working among Iron Age agriculturalists in the Limpopo Valley during the 10th e 13th centuries AD, and potentially also about the nature of women's work in these communities.

Archaeological and Anthropological Sciences, 2018

The identification to species of completely worked bone tools is impossible using standard skelet... more 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.

Journal of Archaeological Science: Reports, 2019

This paper describes possible sound-producing artefacts from two Later Stone Age deposits in the ... more This paper describes possible sound-producing artefacts from two Later Stone Age deposits in the southern Cape, South Africa. Implements previously described as a 'wirra wirra' or 'pendant' from Klasies River main site (KRM), a 'woer woer' or 'bullroarer' and four 'pendants' from Matjes River (MR) are analysed and their sound producing qualities assessed through an actualistic research programme. For comparative purposes, a replica of an ethnographic 'spinning disk' was also spun and its sound recorded. All of the implements, except the MR 'woer woer' produced a sustained, pulsed, whirring sound when spun. Minor adjustments to the MR 5135 replica resulted in successful sound production. The frequency range of the KRM replica and ethnographic KK058 implement produced a frequency variation of between 52 Hz and 200 Hz. The frequency range of the pendant replicas varied from 55.55 to 250 Hz, comparable to other bullroarers. Spinning produces use-wear predominantly on the left laterals of the perforations, whereas pendant use produces use-wear along the upper sector of the perforation, thus allowing us to distinguish these two uses based on the placement of use-wear. We conclude that one of the bone artefacts previously thought to be a pendant, MR 40, most likely functioned as an instrument to produce sound. This investigation thus experimentally confirms that earlier hypotheses that the 'wirra wirra' from KRM and the 'bullroarer' from MR were aerophones are judicious. In addition we demonstrate for the first time that some archaeological pendants, such as MR 40, may have been used as free aerophones or bullroarers.

Journal of Field Archaeology, 2018

New excavations at Border Cave use high-resolution techniques, including FT-IR, for sediment samp... more 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.

South African Journal of Science, 2017

The antiquity of the use of hunting poisons has received much attention in recent years. In this ... more The antiquity of the use of hunting poisons has received much attention in recent years. In this paper we present the results of a pilot study designed to detect the presence of organic compounds, typically of less than 1200 Da, from poisonous plants that may have been used as hunting poisons in the past. We used ultra-performance liquid chromatography connected to a Synapt G2 high-resolution MS-QTOF mass spectrometer (UPLC-QTOF-MS) to provisionally identify plant-based toxins present in (1) extracts of fresh plant material, (2) a blind control recipe consisting of three plant ingredients and (3) a Hei||om arrow poison of unknown ingredients. Although not all expected toxic compounds were identified, those that were identified compared favourably with those reported in the literature and confirmed through databases, specifically the Dictionary of Natural Products and ChemSpider. MS/MS fragmentation patterns and accurate mass were used for tentative identification of compounds becaus...

Journal of Archaeological Science: Reports, 2016

Azania: Archaeological Research in Africa, 2024

Scientific Reports

Journal of Archaeological Science: Reports

South African Journal of Science

PLOS ONE

Arheologia

Southern African Field Archaeology

Journal of Paleolithic Archaeology, 2021

Southern African Humanities, 2015

Quaternary Science Reviews, 2020

Quaternary International, 2018

Archaeological and Anthropological Sciences, 2018

Journal of Archaeological Science: Reports, 2019

Journal of Field Archaeology, 2018

South African Journal of Science, 2017

Journal of Archaeological Science: Reports, 2016

A review of the plant and animal toxins used by the San to poison their weapons.

In this chapter I present the results of a use-trace study conducted on 357 pointed bone tools fr... more 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 defi ned 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.

$Research paper thumbnail of Fracture analysis of bone tools: a review of the micro-CT and macrofracture methods for studying bone tol function$

When bone is dry or subject to high speed impact it assumes the fracturing properties of a brittl... more When bone is dry or subject to high speed impact it assumes the fracturing properties of a brittle solid. Because
of this we can appeal to the mechanics of brittle solid fracture to study the conditions under which bone tools fractured.
This paper presents a review of two relatively new techniques for examining use-related damage in bone tools, namely,
macrofracture analysis and micro-CT. Both methods rely on the breakage mechanics of brittle solids under dynamic loading
conditions. This paper explores these techniques in the context of bone hunting weapon identification. Macrofracture
analysis is an inexpensive, easy-to-use technique that allows for the accurate identification of tools subject to longitudinal
impact, but their absence does not rule out this activity. Micro-CT is a machine that provides 3D X-ray images of objects
and can be used to image bone histological features. The visualisation of micro-cracks with the aid of micro-CT allows
for the identification of various loading conditions where no visible surface use-wear exists. Patterns of micro-crack formation
and degree of propagation can inform on different modes of loading, including static loading from trampling and
dynamic loading from hunting.

$Research paper thumbnail of Macrofracture analysis as a method for identifying bone-tipped weapons: A functional approach to the recognition of Stone Age hunting points$

The use of formally fashioned bone points as possible components in hunting weaponry has been see... more The use of formally fashioned bone points as possible components in hunting weaponry has been seen as a marker of behavioural modernity. Unfortunately, their interpretation as hunting weapons is based largely on morphological analogy with recent hunter-gatherer artefacts. Many studies conducted over the last 30 years have focused on identifying criteria that can be used to establish the function of stone points. There have been no similar studies conducted on bone points thought to have been part of complex weapon systems. This study aims to combine the morphological approach to studying bone points, with macrofracture analysis. The results of a simulated hunting experiment show that macrofractures develop similarly on bone points as on stone points. The results of the macrofracture analysis on archaeological bone points from LSA and MSA contexts in South Africa show that diagnostic impact fractures are present on some of these pieces.

THE CONVERSATION, 2020

The origin of bow hunting has been a hotly debated topic in archaeology for the past two decades.... more The origin of bow hunting has been a hotly debated topic in archaeology for the past two decades. This is because knowing when it emerged has the potential to offer insights into the development of human cognition and the early development of complex technology. The bone arrowhead (insert) found at Klasies River main site has much to teach us. Justin Bradfield and Sarah Wurz What a bone arrowhead from South Africa reveals about ancient human ... https://theconversation.com/what-a-bone-arrowhead-from-south-africa-r...

The layman's version of the Wooding et al. 2017 (South African Journal of Science) paper publishe... more The layman's version of the Wooding et al. 2017 (South African Journal of Science) paper published in the The Conversation. We report on a method for discerning poisons on archaeological artefacts.

South African Archaeological Bulletin, Jul 2014

Stone Age societies are understood largely in terms of their technology. The way in which we fram... more Stone Age societies are understood largely in terms of their technology. The way in which we frame our research and understanding of these past societies is based almost exclusively on stone tools and ceramics, yet these materials represent only a small percentage of recent hunter-gatherer paraphernalia and may not necessarily reflect the complexity of cultural adaptations and technological achievements of the past. Pointed bone tools are present in the archaeological record of almost every ancient society and time-period; yet, for various reasons, they seldom have been afforded the same attention as their stone equivalents. Unless all aspects of past technological systems are acknowledged and understood we risk providing a distorted image of the past.
This thesis begins to explore the variable and diverse functions of pointed bone artefacts in southern Africa during the Later Stone Age from approximately 18 000 years ago until a few hundred years ago when the hunter-gatherer societies practicing a stone age economy came under the influence of immigrant Iron Age farmers. A comprehensive study of bone tools has the potential to provide information about past societies that is simply not available from stone tools and ceramics. In this thesis I look at one aspect of past technology, namely pointed bone tools, that has seldom formed the focus of research. I present the results of a metrical analsyis and three use-trace analyses (micro-residue, use-wear and macrofracture), each designed to provide complementary information about the past function/s of pointed bone tools. Over 300 tools are examined from 12 archaeological sites.
Evidence presented here shows that while manufacturing techniques remain relatively constant throughout the last 18 000 years, greater functional variability among bone points is evident during the last 6000 years and largely parallels the sustained focus on hunting smaller animals. Changes in bone tool form and function do not correlate neatly with lithic technology oscillations or environmental fluctuations and seem to occur during rather than at the boundaries of stone tool technocomplexes. Evidence that bone points were reused after they fractured suggests the importance attached to these tools and raw material. Finally, a range of different arrow forms are recognised that may have the potential to provide an avenue for relative dating.

iScience, 2024

Highlights d GC-MS and UHPLC-MS results of the contents of a 7,000year-old artifact are presented... more Highlights d GC-MS and UHPLC-MS results of the contents of a 7,000year-old artifact are presented d The contents of the femur contain three different plant-based toxins d The presence of toxins indicates that the substance is a poison d The toxins derive from different plant taxa, indicating possible long-distance acquisition

Journal of Contemporary Archaeology, 2021

Contemporary occupation of archaeological sites is fraught with challenges and conflicting priori... more Contemporary occupation of archaeological sites is fraught with challenges and conflicting priorities. While prevailing opinion on heritage management recognises the fluid and continuous nature of archaeological site formation, the role of present-day communities as agents of archaeological palimpsests is often not adequately acknowledged. Contemporary communities, often unrelated to the autochthonous inhabitants of the archaeological sites, occasionally use these sites and landscapes in similar or different ways to how they were used in the past. Their use of these sites, while potentially damaging to the archaeology, simultaneously adds to, and is part of, the life history of the site, of which the excavated material and rock art are but pictures in time. Squatters who appropriate archaeological heritage sites constitute ambiguous communities under current South African heritage legislation. Yet, their role as contributing agents to archaeological sites is no less real. This article presents the case study of Kruger Cave, a Later Stone Age hunter-gatherer rock art site in South Africa, currently occupied by a lay Christian pastor. We document how the pastor is using the site and offer some thoughts around the nuances of negotiating and reconciling archaeological preservation and living heritage management.