Automatic Tool Mark Identification and Comparison With Known Bronze Age Hand Tool Replicas

Abstract

ABSTRACT:The acquisition of high-resolution surface information by advanced documentation methods as short-range laser scanning or closerange photogrammetry can provide novel tool mark research perspectives in the field of archaeological sciences. For this reason, altogether eight different Bronze Age hand tool replicas and their tool marks were surveyed and analysed in this study. The automatic identification of sliding tool marks was carried out in a GIS environment. Based on hydrological and aspect parameters, the various hand tool impressions as watershed boundaries of the surface model could be determined in the developed workflow. After the segmentation of the single tool marks, slope and width values of the patterns were compared with the cutting edges of their replicas and the most used regions of the hand tool heads could be defined by these tool mark characteristics. The variation of midline parameters along the sliding tool marks resulted in significant conclusions about the mounting techniques of the hand tool heads on the handles. A smaller angular value between the replica and the handle produced different hand tool impressions which had a major influence on the woodworking efficiency as well. Furthermore, in this paper presented methods should also help to understand other ancient wood manufacture processes.

Recovering prehistoric woodworking skills using spatial analysis techniques

“…A further interesting result proved the significance of the handle or haft as the long-hafted axes had greater productivity over time during the experimental tree felling work steps (Mathieu et al, 1997). In addition, the handle's mounting angle of a hand tool can also influence the woodworking efficiency as an approximately 13% smaller mounting position has produced around 40% less wood trimming volume within the same time sequence during an archaeological experiment (Kovács et al, 2013). In the beginning of the 1970's, a research group investigated the ancient wood chopping work steps and the results revealed that a stone axe must have been utilised over six times as long as a steel axe for the accomplishment of the same working tasks (Saraydar et al, 1971).…”

“…For this reason, the direction of these edge lines implied the main categories during the definition of aspect classes. The boundaries of aspect changes between these main categories can represent the edges of hand tool impressions and after the intersections with the stream network, the locations of the pour points could be determined (Kovács et al, 2013). This objective, repeatable method determines the one of the core parts of this study since this user-independent exact segmentation process provides the initial situation for the detailed morphological characterisation and classification.…”

“…The pour points of the catchments were precisely defined by the combination of the calculated stream network and the boundaries between the main aspect classes of the surface model. Finally, the watersheds were identified by the "Flow Direction" characteristics and by the pour point positions (Kovács et al, 2013). The aspect calculations were used to help the identification process of the watershed pour points.…”

Interpretation of Hand Tool Movement's Trajectories by Spatial Analysis of Bronze Age Tool Marks

“…For this reason, an exact integration of GIS-based hydrological and aspect investigation techniques can offer userindependent and repeatable tool mark recognition workflow. This method has already been discussed in two previous publications of the authors ( [5], [13]). 2.4.…”

“…Sands [4] has interpreted construction methods from tool marks by photo documentation and labor analysis on selected wooden artefacts from Oakbank Crannog in Scotland. After short-range laser scanning surveys, Bronze Age hand tools and their tool marks were compared and the woodworking efficiency of these replicas were calculated by the authors in a previous study [5]. Similar high-resolution documentation workflow was applied in an interdisciplinary archaeological project where a Bronze Age sluice box from Mitterberg, Austria was reconstructed and investigated after the three-dimensional measurements (Figure 1).…”