Sr-Nd isotopic fingerprinting as a tool for ceramic provenance: Its application on raw materials, ceramic replicas and ancient pottery

The potentiality of isotope analysis has largely been explored in archaeological sciences to date objects, attribute their provenance and depict ancient human dietary habits. However, the potential of this technique for provenance studies of ancient ceramics has barely been explored, due to the fact that the ceramic process often involves the selection of different raw materials and, consequently, different sources of radiogenic isotopes. In this paper,87Sr/86Sr and143Nd/144Nd isotope ratios were measured on raw materials (clays and volcanic temper) that were exploited in antiquity for producing pottery in the Campania region of Italy and, for the first time, on experimental ceramic materials that replicate archaeological pottery. To validate the method, Sr and Nd isotope ratios were also measured on selected archaeological pottery from Cuma. The results of this pioneering approach clearly show that the synthetic mixtures used for the ceramic replicas plot exactly on the theoretical mixing curve between the clay and volcanic temper end-members. On the other hand, technological processes employed during pottery manufacturing such as firing and levigation induce no significant variations in Sr and Nd isotope ratios. Isotope characterisation represents an effective fingerprint of pottery that strictly depends on the geochemical affinity of the raw materials, thus providing a better discrimination among different ceramic productions.