Archaeometric study of African Keay 25.2 amphorae in Catalonia (Spain): a history of importation and imitation

This work presents the results of archaeometric study of Keay 25.2 amphorae from some sites along the Catalan coast (the ancient Roman province of Hispania Tarraconensis, north-eastern Spain), considered to be vessels imported from production centres in Tunisia and, on the basis of the similarity of macrofabric and shape, in particular from the Sidi Zahruni production area (NE Tunisia). A series of 38 amphorae were analysed by thin-section petrography, X-ray powder diffraction and X-ray fluorescence. The chemical data were statistically treated in order to define, for comparison with an established reference group of amphorae from Sidi Zahruni, possible cases of exportation from the Tunisian site to Spain. Many petrographic and chemical groups were identified among the amphorae, and only some of them turned out to come from the North African production centres, mostly Sidi Zahruni. However, some were characterised by metamorphic and igneous inclusions, which are not consistent with the geology of Tunisia, indicating that they had been produced in other areas of the Roman Empire. The petrographic, mineralogical and geochemical affinities of these specimens with Early Roman Catalan amphorae indicate that these Keay 25.2 amphorae were produced in Catalonia, perhaps as imitation products. Identification of imported specimens and also of local imitations contributed to improving our knowledge of economic relations and trade between Northern Africa and Hispania.