Obsidians of Pantelleria (Strait of Sicily): A Petrographic, Geochemical and Magnetic Study of Known and New Geological Sources

This paper provides new petrochemical and paleomagnetic data from obsidian sub-sources on the island of Pantelleria, exploited since the Neolithic. Data has been obtained from 14 obsidian samples from 4 locations: (2 sites), and . Here, we aim to better characterize these obsidians using a cross-disciplinary and multi-analytical approach, to further understand their archaeological significance. Major element analyses (EMP) have enabled two compositional super-groups to be distinguished: (i) , less peralkaline and (ii) distinctly more peralkaline and having almost identical chemical patterns. Trace element analyses (LA-ICP-MS) corroborate major element groupings, with the super-group being further characterized by a pronounced negative europium anomaly. Glass H O contents (FT-IR) reveal an overlap among all the sub-sources (H O = 0.1–0.3 wt. %). Magnetic methods have refined the petrochemical groupings, permitting further distinction between and the super-groups. The occurrence of sub-microscopic (< 1 μm) ferromagnetic minerals results in different magnetic susceptibility and Natural Remanent Magnetization values and allows the best distinction among the products from the chosen sites. When compared with obsidian tools excavated from Bronze-age settlements on the island of Ustica (230 km NE of Pantelleria), 12% are distinctly peralkaline, indicating their provenance to be from the sub-source.