Pattern and Allometric Measurement of Reduction in Experimental Folsom Bifaces

TLDR

Stone tools are reduced during use, and the degree and pattern of reduction influence tool size and form, complicating typological assignment while enabling measurement and analysis of curation. The study applies simple allometric reduction ratios of changing length, mass, or surface area relative to constant thickness to experimental Folsom bifaces used as dart points and reworked during use. The authors measured reduction on these bifaces by calculating ratios of length, mass, or surface area to constant thickness. All measures correlate with the degree of reduction from the known original size, with the length‑to‑thickness ratio best distinguishing earlier and later use episodes, tracking amount and direction of reduction, and revealing patterned distributions measurable in retouched archaeological specimens.

Abstract

Many stone took are reduced during use. Degree and pattern of reduction influence tool size and form, complicating typological assignment but allowing measurement and analysis of curation. We apply simple allometric reduction measures-ratios of changing length, mass or surface area to essentially constant thickness—to a set of experimental Folsom bifaces that were used at dart points and reworked and reduced during use. All measures correlate with degree of reduction from known original size; the simple ratio of length to thickness (L/T) correlates best and distinguishes between earlier and later episodes of use and reduction. Although calibrating variation in allometric reduction measures to common scales remains a challenge, ratios calculated from easily measured dimensions of archaeological tools track the amount and direction of reduction that the tools experienced. Reduction produces patterned distributions; it can be measured in retouched archaeological specimens.