Linking 3D digital surface texture data with ancient manufacturing procedures

Surface texture is a key parameter in archaeological materials, where its study has been central to use-wear research, as well as in the understanding of manufacturing processes. Nowadays, 3D digital surface textures can be characterized from macroscale to nanoscale, using advanced metrology methods and techniques, and by means of 2D profile or 3D areal (non-)contact instruments, which span a wide range and resolution. In this paper, we describe an experiment based on the quantitative description of geometric surface texture patterns (i.e., the microtopography) from 3D scanned archaeological and experimental materials, in order to assess how objects were manufactured in the past. At the end, we aim to differentiate texture patterns; associate them with possible gestures, carving techniques, and used tools; and understand the technical procedure used by the craftsperson. The archaeological object of study is a large fragment of one of the stelae with carved horns on blocks of sandstone, late 4
^th
millennium cal BC, discovered in 2008 in the Neolithic settlement in the Serra del Mas Bonet (Vilafant, Alt Empordà), Catalonia. Experimental replicas of this fragment's surface textures were made in blocks of sandstone coming from the same bedrock. The applied method consisted of using a 3D structured light scanner, with a submillimetre resolution, to capture the geometric surface texture of both prehistoric and experimental objects. Then, using surface roughness areal parameters, regulated by international standards, to describe quantitatively the texture patterns of a set of sampled areas. After that, comparisons were made, and a first conclusion is here presented.