Investigating experimental knapping damage on an antler hammer: a pilot-study using high-resolution imaging and analytical techniques

https://doi.org/10.1016/j.jas.2013.07.016Get rights and content

Highlights

  • An antler bar-hammer was used to replicate flint handaxes.

  • The hammer was studied using non-destructive imaging and analytical techniques.

  • Use-wear damage on the working area and the handle were compared.

  • Features indicative of flint-knapping are identified for antler percussors.

Abstract

Organic (bone, antler, wood) knapping tools were undoubtedly a component of early human tool kits since the Lower Palaeolithic. Previous studies have identified pitting and the occasional presence of embedded flint flakes as important features for recognizing archaeological bone and antler percussors. However, no systematic protocol of analysis has been suggested for the study of this rare archaeological material. Here we present qualitative and quantitative results of a preliminary analysis of an experimental knapping hammer, using a novel combination of microscopy (focus variation optical microscope and scanning electron microscope), micro-CT scanning and energy dispersive X-ray spectroscopy. These imaging and analytical techniques are used to characterize use-damage from the manufacture of handaxes. This paper highlights the strengths and weakness of each technique. Use-wear on the working area included attritional bone loss, micro-striations and compaction of the outer layer of the antler matrix from repeated hitting of the beam against the sharp edge of the handaxe during knapping. Embedded flint flakes were also identified in the pits and grooves. This combination of high-resolution imaging techniques is applicable to fragile archaeological specimens, including those encrusted by sediment or encased in matrix.

Introduction

In recent years, new and increasingly sophisticated imaging and analytical techniques have been applied to the study of past human behaviour: optical and laser microscope, X-ray, CT and Micro-CT scans, just to mention a few (e.g. Abel et al., 2012, Bello et al., 2013, Boschin and Crezzini, 2012, Evans and Donahue, 2008, Le Bourdonnec et al., 2010). The use of soft (bone, antler, wood) hammers and retouchers was a key innovation in early stone tool technology, first recorded in the archaeological record during Lower Palaeolithic (Acheulian of Boxgrove, UK ∼500 kya; Wenban-Smith, 1985, Wenban-Smith, 1999). The use of antlers as soft hammers can be identified from characteristic damage on the working area in form of micro-fractures. These have been described and recognized since the beginning of the 20th century (e.g. Bourlon, 1907, Girod and Massenat, 1900, Henri-Martin, 1907-1910). However it is the presence of small flint chips embedded in the surface of an antler that can ultimately confirm the use of an antler as a tool-maker. These small flint residues can be observed using a hand lens and binocular microscope at low magnification, but more informative results can be obtained using higher magnification photography and scanning electron microscopy (Bordes, 1974, Mallye et al., 2012, Olsen, 1989).

Several experimental studies have explored the use of bones as soft-hammers and retouchers, either as percussors or pressure flakers (e.g. Karavanić and Šokec, 2003, Mallye et al., 2012, Newcomer, 1971, Rosell et al., 2011, Semenov, 1964, Wenban-Smith, 1985, Wenban-Smith, 1999), however, antler knapping-hammers have received little systematic attention (Lyman, 1994; but see Bordes, 1974, Olsen, 1989, Shipman and Rose, 1983). This is surprising as antler is the preferred soft-hammer for thinning and finishing of experimental handaxes, Mousterian scrapers and Upper Palaeolithic blades (Bordes, 1974, Crabtree, 1970, Flenniken, 1984, Johnson, 1978, Knowles, 1953, Newcomer, 1971, Ohnuma and Bergman, 1982, Whittaker, 1994, Wymer, 1968). The lack of detailed documentation and description of traces of use on antler knapping-percussors presents a major stumbling block to identifying fragmentary (Jéquier et al., 2012), poorly preserved, sediment-encrusted (Kuhn et al., 2008) or contentious archaeological examples (Goren-Inbar, 2011).

This paper presents the results of a preliminary analysis to document use-damage on an experimental knapping hammer using a range of analytical and imaging techniques (i.e. micro-computed tomography, focus variation microscopy, variable pressure scanning electron microscopy and energy dispersive X-ray spectroscopy). The strength and weakness of each technique have been highlighted. We illustrate microscopic use-wear features that are diagnostic of antler knapping hammers and propose a protocol for their analysing.

Section snippets

Material

The soft hammer used in the experimental study (Fig. 1A) was cut from the beam of an antler of a whitetail deer (Odocoileus virginianus) using a metal saw. Although cuts are still visible at the base (‘handle’) of the hammer, extensive use-damage has removed all but a vestige of the saw-marks at the ‘apical’ end (Fig. 1B). The hammer was part of the tool-kit used during flint-knapping experiments conducted at Boxgrove between 1995 and 1996. These experiments replicated sharp ovate handaxes

Methods

The antler was examined initially with a variable magnification binocular and observations were aided by illumination from a fibre-optic light source. Drawings were used to record the location and intensity of damage, and to indicate the position of the flint chips. An un-modified area of the antler used as a control for surface texture was also analysed. This corresponds to its central basal portion, where the hammer was held (Fig. 1F). Comparisons were also made with natural surface

Results

The surface of the antler used for hammering displays extensive modification, with the most concentrated damage near the apical end covering an area of about 240 mm2. The intensity of use is visible on the CT sections (Fig. 1B–C), which illustrate attritional loss of the outer cortical surface towards the apex. In this area, the cortical bone has been penetrated and the internal trabecular tissue exposed (Fig. 1C – Cross-sectional profile 1, CS1). The CT sections also show increased density of

Discussion

The different techniques employed illustrate microscopic features that are diagnostic of antler knapping hammers. Each technique has advantages and limitations for this type of analyses. Micro-CT scanning, as well as recording the gross 3D surface morphology (Fig. 1), revealed the extent of the attritional loss of the outer cortical surface and the density differences associated with compaction due to repeated hammering (Figs. 1 and 4). Both cortical loss and compression provide new

Conclusion

Different non-destructive imaging and analytic techniques were used to study and quantify the macroscopic and microscopic use-wear modifications on an experimental antler hammer. These techniques are applicable to fragile archaeological specimens, including those encrusted by sediment or encased in matrix. Previous studies have identified pitting and the occasional presence of associated embedded flint flakes as the main features for recognizing archaeological bone and antler percussors (

Acknowledgements

This work was part of the Ancient Human Occupation of Britain project, funded by the Leverhulme Trust and the Human Behaviour in 3D project funded by the Calleva Foundation. We are grateful to the flint-knappers who participate in the experiments at Boxgrove and to Lady Maude of Redvins for procuring the antler hammer described in this paper. We thank Alex Ball, Thomasz Goral and Anton Kearsley for their help while conducting SEM analyses.

References (49)

  • A. Negash et al.

    Source provenance of obsidian artifacts from the Early Stone Age (ESA) site of Melka Konture, Ethiopia

    J. Archaeol. Sci.

    (2006)
  • S.L. Olsen

    On distinguishing natural from cultural damage on archaeological antler

    J. Archaeol. Sci.

    (1989)
  • S.C. Phillips et al.

    Initial source evaluation of archaeological obsidian from the Kuril Islands of the Russian Far East using portable XRF

    J. Archaeol. Sci.

    (2009)
  • J. Rosell et al.

    Bone as a technological raw material at the Gran Dolina site (Sierra de Atapuerca, Burgos, Spain)

    J. Hum. Evol.

    (2011)
  • C. Verna et al.

    The earliest evidence for the use of human bone as a tool

    J. Hum. Evol.

    (2011)
  • R.L. Abel et al.

    A palaeobiologist's guide to ‘virtual’ micro-CT preparation

    Palaeontol. Electron.

    (2012)
  • A. Averbouch et al.

    Fiche percuteur sur partie basilaire de bois de cervidé

  • S.M. Bello et al.

    3-Dimensional microscope analysis of bone and tooth surface modifications: comparisons of fossil specimens and replicas

    Scanning

    (2011)
  • F. Bordes

    Percuteur en bois de renne du Solutréen supérieur de Laugerie-Haute Ouest

  • M. Bourlon

    Un os utilisé présolutréen

    B. Soc. Préhistorique Fr.

    (1907)
  • F. Boschin et al.

    Morphometrical analysis on cut marks using 3D digital microscope

    Int. J. Osteoarchaeol.

    (2012)
  • D.E. Crabtree

    Notes on experiments in flint knapping: 4. Tools for making flaked stone artifacts

    Tebiwa

    (1967)
  • D.E. Crabtree

    Flaking stone with wooden implements

    Science

    (1970)
  • R. Danzl et al.

    Focus variation – a new technology for high resolution optical 3D surface metrology

  • Cited by (0)

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