Iron and base metal smelting at Populonia- Baratti (Southern Tuscany, Italy) in the 1st Millennium B.C.: a review of recent research

A key role in the production and trade of metals (especially, but not exclusively, iron) in the Mediterranean area during the 1st Millennium BC, was played by the Etruscan town of Populonia. A detailed research program on four main excavation sites in the Populonia-Baratti industrial zone (Poggio della Porcareccia, Casone, Campo VI and the Baratti beach deposit) has been undertaken, with the aim of establishing the types and extent of metallurgical activities for iron and non-ferrous metals (mainly copper and tin), as well as on the provenance of smelted ores in the Etruscan and Roman periods. These are the main (preliminary) results: • although most archeometallurgical wastes at Baratti-Populonia can be ascribed to iron production, the existence of an earlier (and partly coeval) copper metallurgy can also be documented in the area, particularly from the slag beach deposits; • two different types of copper slags, which could be related to different metallurgical steps, have been distinguished; • the mineralogical and compositional features of some metallurgical scraps (Campo VI), dating to the 3rd century BC or earlier, provide evidence of local bronze production, in agreement with archaeological data; • trace element geochemistry (e.g., tin anomalous content of some iron slags) and Pb-isotope analyses indicate that iron ores came mainly from Elba and, to a lesser extent, from the Campiglia Marittima district (where Fe-Sn ores are common, e.g. at Monte Valerio); the latter district appears to be the most likely source area for smelted copper and, possibly, for tin; • iron smelting was practiced in slag-tapping, shaft furnaces built of sandstones and internally lined with refractory clays, which were obtained by mixing of local clays with sand, chamotte and straw.