A geometric index of reduction for unifacial stone tools

Issues relating to the maintenance and renewal of stone tools have become increasingly important in studies of prehistoric technologies. This paper presents an index of reduction for unifacial side-scrapers, a common tool form in many assemblages. The index is based on a simple geometric model of flake cross-sections. It is unprejudiced by varying paths of reduction and the original sizes of tools. However, the index is potentially subject to bias resulting from variation in the form of tool blanks: In spite of these constraints, experimental data suggest that the index constitutes' a reliable measure of the extent of tool reduction.