Investigating the potential of basalt tools through use-wear experiments

Basalt is a widely used raw material for tool manufacture at prehistoric sites, but a unified methodology for assessing how hominins used basalt in prehistory is lacking. A comprehensive experimental investigation of basalt tools is, thus, necessary to establish a reliable methodological framework that can be used to explore the functional properties of archaeological basalt assemblages.
Experimenting with basalt is a challenging task due to its tough nature and variability. This makes it difficult to control and characterize trace patterns accurately. This study aims to investigate the role of basalt variability in use-wear formation processes, specifically focusing on basalt varieties present in different Lower to Upper Pleistocene archaeological sites in Africa (Olduvai Bed 2 FC East and West in Tanzania, and Mieso Piedmont in Ethiopia), Asia (Bagratashen I in Armenia) and Europe (Abri du Maras in France).
Basalt varieties were characterised using SEM-EDS analysis. Sequential experiments were conducted, using the experimental basalt tools in different activities, including butchery, hide, bone, and woodworking to determine use-wear formation. Subsequently, the potential was evaluated of a multi-scalar integrated approach that combines optical and scanning electron microscopes to analyse macro- and micro-wear traces on basalt.
Our results provide useful information on how differences within the raw material affect the formation of use-wear on basalt. Additionally, the combined utilisation of various microscopes allowed us to gather comprehensive and complementary information on such a complex raw material like basalt and to characterise thoroughly the diagnostic features of the micro-wear traces (e.g., edge damage, rounding, polish).
This study represents a significant progress in comprehending wear formation on basalt tools and provides a reliable basis for functional studies of archaeological basalt assemblages.