Measuring stone artefact transport: the experimental demonstration and pilot application of a new method to a prehistoric adze workshop, southern Cook Islands

This paper presents a new method, based on the calculation of a Cortex Ratio, capable of contributing towards measures of stone artefact transport in Polynesia. A set of ratios can be calculated by comparing the observed amount of cortical surface area and volume in an assemblage with what is expected should all the products of reduction remain. Because raw material shape and size is controlled for using geometric equations, an estimate for the number of preforms produced from an assemblage also is possible. The method is experimentally demonstrated and applied to an archaeological early stage adze manufacturing assemblage from Moturakau Rockshelter, Aitutaki Island in the southern Cook Islands. Application of the method, in combination with geochemical and chronological analyses, shows that the number of preforms produced and transported, as well as the frequency of their transport, changed over time but the geographic scale of distribution remained the same, essentially local to Aitutaki.