The island of Elba (Tuscany, Italy) at the crossroads of ancient trade routes: an archaeometric investigation of dolia defossa from the archaeological site of San Giovanni

Dolia are large pottery containers used in Roman times for the storage and fermentation of wine. They were produced in specialized pottery workshops (figlinae) and were typically marked with specific epigraphical stamps, which represent a major tool to unravel their provenance and trade. In this work we present the preliminary results of a study of two dolia defossa, recently found at San Giovanni (Portoferraio, island of Elba, Italy) during 2012-2014 archaeological excavations in a Roman farm (late 2nd cent. BC-1st cent. AD), devoted to wine production and probably constituting the antecedent archaeological phase of the adjacent "Villa delle Grotte". Based on archaeological (epigraphic) evidence, five different production areas have been hypothesized: 1) Elba island, where the dolia have been found; 2) the municipal figlinae in the Pisa territory; 3) the middle catchment of the Tiber river (central Latium) where "urban" figlinae occurred; 4) the figlinae of Minturno (southern Latium), a locality known both for wine production and exportation and for the presence of ancient figlinae; 5) the municipal figlinae in the Volterra territory. Archaeometric analysis of tempering agents intentionally added to the clay for the manufacturing of the dolia, particularly magmatic lithic fragments and clinopyroxene crystals, allowed us to suggest that the watershed of the central Tiber Valley - including different volcanic centres belonging to both Tuscany Magmatic Province (Monti Cimini) and Roman Magmatic Province (Monti Vulsini and Vico volcano) - could have been the most likely sites of production of the dolia found at San Giovanni. Alternatively, the site of Minturno (southern Latium) could be proposed.