In Bronze-Age Mediterranean archaeology, lead isotope provenance studies of metals have provided otherwise unavailable information about metal mining and smelting centres and the trade of metals. There is no similar scientific information about base non-ferrous metals in Europe in the Roman period, but a considerable body of written and archaeological evidence of Roman mining and smelting exists. Less in known about the origin of metal supplies for metal smithing workshops outside the Romans empire. This paper summarises the results of the first attempt at finding the mineral sources of such metals using compositional (XRF) and lead isotope analyses.
From the settlement of Jakuszowice in southern Poland, a group of base metals dated to AD 200–400 was analysed and the results compared with lead isotope ‘fingerprints’ of ores and some Gallo-Roman bronzes published previously. The finds from Jakuszowice include numerous imported artefacts, such as Roman coins and glass beads, which indicate links with the Roman empire. However, many small decorative objects of metal were made in the smith's workshop on the site. Compositional analyses of the fragments and artefacts from the smithy show that the types of alloys are broadly similar to the metals used in the Roman empire. But only about 30% of the metal analysed shows lead isotope compositions consistent with sources within Roman Europe. The majority of metal seems to be imported from the much nearer ore deposits in the Erzgebirge, in present-day Germany and the Czech Republic.