White Marble Sourcing and Regional Workshop Dynamics in Roman Thrace: An Archaeometric Study of Votive Reliefs

Marble votive reliefs from rural sanctuary contexts have seldom undergone archaeometric investigation, despite their potential to illuminate regional trade and production networks. This study focuses on such reliefs from Philippopolis and its hinterland, with particular emphasis on cult sites in Roman Thrace. Using a stable isotope (δ13C and δ18O) and trace element analysis via ICP-MS, integrated with petrography, the provenance of marble used in these artefacts was determined. The results identify Asenovgrad marble—prevalent in the Rhodope Mountains—as the primary material, with a minority of examples sourced from Prokonnesos and the southeastern Rhodopes. The predominantly fine-to-medium-grained nature of Asenovgrad marble may have facilitated the execution of small, detailed iconography. The consistent use of this local stone across votive types and deities implies centralised production, likely by one or more local workshops. These findings contribute to our understanding of marble selection, workshop localisation, and regional connectivity during the Roman period. They also highlight the importance of combining geochemical and petrographic methods for reliable marble provenance. This research demonstrates that even modest sanctuaries can yield critical data on raw material distribution and artisanal practices within broader economic and cultural frameworks.