Curated lithic technology

Curated character of the Initial Upper Palaeolithic lithic artefact assemblages in Bacho Kiro Cave (Bulgaria)

Our investigation reported in this article focus on the study of over 2,000 lithic (stone) artefacts excavated at the site of Bacho Kiro Cave in Bulgaria from layers dated to about 45,040–43,280 cal BP. We analysed raw materials using petrography and identified many artefacts made from flint sourced some 130–190 kilometres from the cave; we also mapped and classified how the tools were produced, modified and re-worked. We applied chaîne opératoire and reduction sequence approaches (i.e., when and how blanks were produced, how tools were curated and re-used) to understand not just “what” tools were made, but how and where they were used and modified. We found that a large proportion of tools were made from non-local flint, Lower Cretaceous flints from the Ludogorie area (≈160-190 km away) accounted for ~62% of identified types; Upper Cretaceous flints from the Danube region (~110-130 km away) also appear in the assemblage. The technology is dominated by flakes (35.87%), blades (15.18%), and retouched blanks (15.04%). Minimal core production suggests that many tools were brought in already worked (or blanks transported) and then maintained rather than produced fully on site. In summary, the assemblage suggests deliberate selection and transport of finished or semi-finished products and a high level of tool curation — not simply production and discard based on local materials.