Testing a taphonomic predictive model of edge damage formation with Middle Stone Age points from Pinnacle Point Cave 13B and Die Kelders Cave 1, South Africa

Abstract

The interpretation of taphonomic and behavioral lithic edge wear formation is complicated by equifinality of edge damage morphologies. Rejecting hypotheses that edge damage originates from taphonomic processes is standard practice for many archaeological analyses and should be incorporated into lithic use-wear more explicitly. Quantitative hypothesis testing is advocated here, and facilitated by recording edge wear observations in an image referenced GIS spatial environment. A taphonomic predictive model was generated using trampling and flint-knapping experiments. Trampling experiments were conducted to determine how edge damage is distributed along tool edges due to non-use related, taphonomic processes. Experiments designed to test the assumption that undisturbed flakes do not preferentially orient either surface side-up (dorsal or ventral) were performed. Furthermore, it is argued that artifact orientation data, if available, can also be used to assess whether the frequency of edge damage is correlated with the degree of disturbance. This taphonomic predictive model is then statistically compared with frequency and distribution edge damage data from two South African Middle Stone Age sites. The research presented here illustrates the usefulness of edge damage distribution analysis for accounting for taphonomic processes as causal agents of edge damage formation, and strengthening behavioral interpretations regarding tool function. Bringing tool wear observations into a uniform spatial structure is one avenue for standardization of lithic use-wear analysis.