Caratterizzazione petrografica di materiali lapidei di reimpiego in contesti medievali in area cisalpina.In: PIERRES ERRANTES Stones’ Journeys from Classical Antiquity to Middle Ages, from Eastern Mediterranean to the Alps

Abstract As part of the PRIN PNRR project Pierres Errantes, and in collaboration with the University of Pavia, the University of Piemonte Orientale and the Brera Academy, the Earth Sciences Department of the University of Torino analyzed 25 Roman-era stone artifact samples repurposed during the Middle Ages in the Vercelli and Novara areas (Piemonte region, NW Italy). A total of 25 samples were examined: 14 of sedimentary, 1 of magmatic, and 10 of metamorphic origin, 7 of which are marbles, while the remaining 3 are primarily silicate-based. Most of the samples consist of soft, easily workable stones, suitable for sculpting funerary monuments, sarcophagi, capitals, columns, and other architectural elements. Petrographic characterization established the identification of geographical provenance of the stones and, in some cases, their geological domain, unit, and specific quarry site. The study results were cross-referenced with existing petrographic and archaeometric databases in literature, indicating that sedimentary and silicate materials primarily originated locally (from Piemonte) or from extractive basins in the Western Alps. In contrast, the characteristics of the marbles suggest a provenance mainly from the Eastern Mediterranean region (Turkey).