SOURCE PROVENANCE OF ANDESITE ARTIFACTS USING NONDESTRUCTIVE XRF ANALYSIS

X-ray fluorescence spectrometry is a common technique in determining t he elemental composition of lithic materials. With the exception of gl assy volcanic rocks like obsidian, most rock types are prepared for an alysis by conversion of specimens to powder or glass in order to reduc e the effects of irregular surface topography and internal inhomogenei ty. Concern for artefact conservation necessitates a less destructive preparation technique, which has not been widely investigated except w ith respect to obsidian artefacts. A series of analyses of andesitic a nd dacitic rocks explore the degree of influence of surface topography and inhomogeneity to determine if less destructive procedures can dis tinguish effectively between different geological sources. Focusing pr imarily on major elements, results suggest that source discrimination can be achieved using data produced by any of the three sample prepara tion procedures investigated: quantitative chemical data from glass be ads; semi-quantitative chemical data from polished rock billets; or X- ray intensity ratios from unmodified flakes or polished billets. (C) 1 997 Academic Press Limited.