Tool-use experiments to determine the function of an incised ground stone artefact with potential symbolic significance

Ground stone implements are found across most Australian landscapes and are often regarded as Aboriginal tools that were used for processing or modifying other items such as plant foods, plant fibres, resins, bone points, pigments and ground-stone axes and knives. Less common are ground stones modified for non-utilitarian, symbolic purposes; for example, polished and carved stone ornaments; ritual implements such as cylcons and tjuringa sacred stones; and unused, well-crafted ground-stone axes. In this paper, we report on the function and potential significance of an unusual ground stone artefact from a site near Bannockburn, southwestern Australia. A set of regularly spaced, shallow grooves has been cut into the surface of each side of the stone. Use-wear, residues and experimental replica tools indicate that the grooves were probably made with a stone flake and then used to shape or sharpen wooden implements such as spear points or the edges of boomerangs or other weapons. The microscopic wear outside the grooves indicates contact with soft wood or other plant material, possibly a soft plant fibre bag. We suggest that the Bannockburn artefact primarily functioned as a woodworking tool, but the even spacing of the incisions suggests that they were intentionally placed, perhaps to convey a special meaning, perhaps as a tally system or other form of communication.