Photogrammetric 3D modelling and experimental archaeology reveals new technological insights into engraved soapstone sinker production in Western Norway (6400-3300 cal. BC)

Abstract

This pilot research presents the first study integrating digital submillimetre image-based 3D modelling with experimental archaeology to examine how soapstone sinker stones, dated to the late Mesolithic and early Neolithic periods in Western Norway (6400-3300 cal. BC), were manufactured and engraved. Photogrammetry was used as a bridging method to compare archaeological artefacts and experimental data. Applying the same high-accuracy digital solutions to five archaeological and 26 experimentally commissioned replica sinkers, permitted linking characteristic features of engraved surfaces with specific tools and techniques. This enabled identifying and distinguishing flint-made surface modifications from quartz, bone and sandstone, and revealed novel information on key aspects of the sinker’s biographies and chaîne opératoire, including the initial shaping of the blank by means of grinding stones, the relative chronology of the engraving process, and damage to the artefact surface caused during use-life and via post-deposition processes. This study suggests that the central furrow on the soapstone sinkers, assumed to function for fastening a line, was produced in a consistent way, likely with quartz tools, while other incisions showed more variation. Aesthetic concerns are one possible reason for these differences, though others should be considered; future studies may help provide greater insight into the reasons driving this preference.