Initial Upper Paleolithic leaf-shaped biface from the Kara-Bom site: technology, function, and context

A leaf-shaped bifaced tool distinguished by the thoroughness of its manufacturing and typical shape was discovered in 2004 in a crumbled section of excavations done in 1991. This article describes the technological and functional features ofthat artifact. Using comparative analysis of the typologically similar Upper Paleolithic tools from the same region, the problem of its cultural and chronological attribution is discussed. Morphological and technological analysis has shown that the sequence of the tool processing was mainly aimed at producing symmetric elongated biconvex leaf-like shape with the basal part remaining rounded and relatively massive, and narrowing down and thinning of the object in its distal part. The complex of use-wear traces which are observed on the tool is not typical of bifacial tools used for carving animal carcasses. Traces typically appearing from the contact with hard organic material which were caused by fastening the object in a special device have been found on the protruding parts of tool surface in its base area. It may be suggested that the tool could have been used as a pointed weapon of close combat. This interpretation of the technological sequence of shaping and functional purpose of leaf-shaped bifaces is new. Although bifaced tools are common for the entire territory of the Early Upper Paleolithic blade industries, leaf-shaped bifaces used as penetrating weapon have not been known in the Early Upper Paleolithic industries outside the Altai Mountains. The available leaf-shaping and oval varieties were intended for cutting. The tradition of making bifaced leaf-shaped points used as penetrating weapons is an example of regional variability of the Kara-Bom tradition in the Altai Mountains.