Characterization and origin of ancient metallurgical slags from the ancient settlement of Archampolis, Euboea Island, Greece

In the present study, metallurgical slags were investigated and characterized concerning their mineralogy, chemistry, and texture. The slag samples were collected close to the ancient village of Archampolis, located on southern Euboea Island, Greece. The aim of the study was to define the kind of archaeometallurgy, i.e., extraction of copper, silver, or iron, as well as to suggest possible sources of the ores which were used as raw materials burned in the kilns. Qualitative mineralogy and texture of the slags were performed using X-ray diffraction (XRD) and scanning electron microscopy (SEM-EDS). The determination of the major and trace elements of the samples was performed by X-ray fluorescence (XRF). By combining all analytical results, it was concluded that the metallurgy was applied for iron extraction, as the samples consisted of ferrous, glassy slags, while one sample was interpreted as a semi-melted host rock containing the original minerals. Geochemically, it turned out that certain slag pieces are enriched in Cu, As, Pb, and Tl, which indicates a possible origin of the initial ferric ore from the oxidization of the mixed sulfide ore. Such primary and oxidized polymetallic mineral deposits occur in the area of south Euboea Island, some of which have been exploited since the Antiquity. Another possible source could be Andros Island, being the closest area to Archampolis seawards, which hosts significant deposits of iron ores, most of them exploited for centuries.