Ceramic raw materials: how to recognize them and locate the supply basins: chemistry

Provenance studies of archaeological ceramics by analysis of their elemental composition are based on the assumption that clays can be distinguished, which were used for pottery manufacture in different workshops or production centres. The clay pastes used for the ceramic manufacture were prepared from natural raw materials extracted commonly in the vicinity of the production sites. Due to different geological contexts of local raw material sources, differences of their elemental compositions can be expected, which are propagated to elemental compositions of the ceramics. The general distinctiveness of natural raw material sources is presumed in the 'Provenience Postulate', which, though, has to be verified in each case study. For investigation of ceramics and raw materials potentially used for their manufacture, different practices of clay paste preparation have to be considered which might confine the direct comparison. In the present paper, the study of raw materials will be introduced as integral part of ceramic provenance studies. Issues, such as intra-source and intersource variation, elemental composition in context with clay type and accessory mineral, clay paste preparation, and methodological constraints will be discussed by means of raw material and ceramic data from Greece and the Greek islands.