Into the light: The effect of UV light on flint tool surfaces, residues and adhesives

Abstract

Functional studies of prehistoric stone tools are often hindered by the surface preservation of the artefacts. Archaeological residues and use-wear can differ from their experimentally reproduced counterparts to an extent that their identification is not possible by simple comparison. An understanding of how stone tools and residues change over time is thus essential for a better view of past human technology. In open-air site contexts, UV light is the first degradation agent to impact lithic tools before their burial. Even though UV light has been mentioned as an alteration process and its effects on certain mineral and organic materials are known from other scientific fields, it has never been thoroughly studied in archaeology. This study provides a synthesis of the effect of UV light on organic materials and presents the results of the first controlled experiment ever carried out in archaeology to investigate the impact of UV light on flint tools and adhesives.