Research of knapping techniques by three-dimensional modeling methods (evidence from the Obishir-5 site, Kyrgyzstan)

This article discusses the application of 3D modeling methods for analyzing the collection of cores from the Obishir-5 site (Fergana Valley, Southwestern Kyrgyzstan). Using literature and archaeological evidence, the team of authors has developed a list of criteria for determining the pressure and percussion knapping techniques thus making it possible to attribute most of the cores (63 pcs.) from the collection of the Obishir-5 site to one of the two techniques and to divide the artifacts into two respective groups. One of the main criteria - average value of the angle between the striking platform andflaking surface - was calculated exclusively by using the three-dimensional modeling methods. The study also intended to establish which other morphometric characteristics would be helpful for analyzing and identifying various knapping techniques. The following parameters were calculated using the scaled high-precision 3D models of cores (41 pcs.): length, width, and height of the core; height and width of the splitting surface; degree of convexity on the profile of the splitting surface, and degree of convexity of the platform edge. While the values of length-to-width ratio and front height-to-width ratio were similar in the cores of both groups, differences have been discovered in the indices of convexity of the front profile and especially in the values of convexity of the platform edge. The similarities in proportions can be explained by common prismatic and subprismatic cores of slightly elongated proportions with wide and low flaking surface in both groups. However, the sizes of the typologically similar "pressure” and "percussion” cores were different, as indicated by significant difference in volume. The convexity of the working surface in plan and profile turned out to be the sign of pressure techniques in the lithic industries from the site.