A new approach to measure reduction intensity on cores and tools on cobbles: the Volumetric Reconstruction Method

Knowing to what extent lithic cores have been reduced through knapping is an important step toward understanding the technological variability of lithic assemblages and disentangling the formation processes of archaeological sites. In addition, it is a good complement to more developed studies of reduction intensity in retouched tools and provides information on raw material management or site occupation dynamics. This paper presents a new methodology for estimating the intensity of reduction in cores and tools on cobbles, the Volumetric Reconstruction Method (VRM). It is based on a correction of the dimensions (length, width, and thickness) of each core from an assemblage. The median values of thickness and platform thickness of the assemblage's flakes are used as corrections for the cores' original dimensions, after its diacritic analysis. Then, based on these new dimensions, the volume or mass of the original blank are reconstructed using the ellipsoid volume formula. The accuracy of this method was experimentally tested, reproducing a variety of possible archaeological scenarios. The experimental results demonstrate a high inferential potential of the VRM, both in estimating the original volume or mass of the original blanks and in inferring the individual percentage of reduction for each core. The results of random resampling demonstrate the applicability of VRM to not size-biased archaeological contexts.