Comparing experimental core and bifacial debitage in the context of Sibiryachikha Middle Paleolithic variant in Altai

The article discusses the results of flaking debitage comparison obtained from the planoconvex bifacial technology and radial/orthogonal core production methods. The comparative analysis was based on the experimental data obtained from the experiments on core flaking and bifacial tools production in the industry of Chagyrskaya Cave, a key site of the Middle Paleolithic Sibiryachikha variant in Altai Mountains. The experiments were carried out on local pebble raw materials. The Sibiryachikha flaking based on flake manufacture within orthogonal and radial methods, as well as the production of asymmetric planoconvex bifacial tools. The combination of different methods in the assemblage causes a number of problems related to the identification of flakes/chips from a flaking system in the collection. The analysis of experimental data allowed identifying a number of characteristic features allowing to distinguish core flaking from bifacial production. These are primarily flake size, which does not exceed 4 cm in the largest dimension, the presence of typologically identifiable bifacial thinning flakes in the collection, the portion offakes with cortex among flakes under 4 cm, and a number of characteristics of the proximal zone and general morphology of the flakes. These include a curved lateral profile, oblique, greater than 120°, angle between the ventral surface and the striking platform, presence of a lip, overhang trimming, and the miniature striking platform. Our results suggest that high values of each of these characteristics in the Sibiryachikha complexes indicate the processes of bifacial tool production directly at the site.