"...nunc et in Bergomatium agro..." The zinc mining area in the Dossena-Gorno District near Bergamo as a possible source for Roman Brass

Pliny writes in the first century AD that the mineral complex called cadmea was found in contemporary times in the region of Bergamo, at the extreme north of Italy (Pliny Naturalis Historia 34:2). In this context, cadmea is a material that when combined with copper produces aurichalcum, a copper-zinc alloy used for sestertii coins (Pliny 34:4). This statement was the starting point of a study on the mining landscape in the area of the municipality of Dossena, in the Dossena-Gorno Pb-Zn mining district, the only zinc deposit in the region of Bergamo. The zinc mineralization in this mining area is mainly composed of calamine and sphalerite. The mining activities, alive until the 1980s, have their beginning in much more ancient times, as supported by old mining structures,still clearly visible in the mining landscape and the archaeological evidence attested in neighboring areas. Since 2016, small-scale surveys in the area of Dossena have revealed numerous pre-modern mining traces ranging from open-cast mines, collapsed mine shafts (Pingen), and subterranean mines partially made with fire-setting and/or pickwork. To complete the richness of the ancient local vestiges, possible remains of ancient settlements and sites for the thermic treatment of the mineral have been also documented. As this preliminary phase of the project was conducted with a selection of non-invasive techniques, the area was also investigated with remote-survey, through the study of satellite data, conducted for the highlighting of traces typical for ancient mining areas, which will guide the future developments of the field survey.