Attribution and variability of multilayered Paleolithic complexes: the case of the Obi-Rahmat tool kits

The tool collections found in multi-layered Paleolithic sites are not only a result of various life activities that occurred at these sites, but they also correspond to the cultural or industrial variants in the contexts in which they were produced. The composition of the tool collections is contingent upon the extent of the excavated area of the site. The functionality of the tool sets may change over time in response to fluctuations in palaeoenvironmental conditions, seasonal patterns of habitation, and the availability of lithic raw material at the site. The ana­lysis of multilayer Paleolithic industries and their att­ribution is a challenging problem, as it requires the analysis of numerous parameters. In order to address this challenge, researchers often employ a method of calculating percentages of different inventory categories and linear correlations. In this paper the results of the study of 35 tool sets from the Obi-Rahmat, a key-site of the Middle Paleolithic Obi-Rahmatian variant in West Central Asia is presented. The app­lication of a set of multivariate statistical methods, including unconstrained seriation, principal coordinates analysis and correspondence analysis enabled to attribute the studied collections to one industrial variant and estimate their variability. The variability of the Obi-Rahmat lithic collections is predominantly of a chronological nature, with the lower layers exhibiting characteristics indicative of a repeated­ly visi­ted hunting camp. This is evidenced by the pre­sence of complexes in which various retouched points and side-scrapers predominate. In the upper layers, the focus of work activity shifts to the proces­sing of hard and soft organic materials, with a greater proportion of splintered tools, burins, perforators and end-scrapers in the complexes. We assume that the change in the functionality of the excavated area of the site from the bottom to the top could be related to the duration of occupation episodes.