Archaeometric investigations on bronze artefacts of Chierici collection: preliminary results on metal supply strategies

The Chierici collection consists of more than 400 finds in copper alloy and the 145 objects conserved in the Musée d’Archéologie nationale et domaine national of Saint–Germain– en–Laye. A selection of 15 finds (VI-V century BC) from the excavations conducted by Cherici at S. Polo-Campo Servirola, now preserved in the Civic Museums of Reggio Emilia, were studied in the framework of the ANRJCJC Itineris project (https://itineris.huma-num.fr/). The results will be compared with those obtained on coeval artefacts from archaeological settlements in Piedmont region. The aim is to highlight changes in the choice of mineral supply sources and the strategies adopted. Chemical and microstructural characterizations were achieved through a multi-analytical approach, including reflected–light optical microscopy, scanning electron microscopy coupled with an X–ray energy dispersive spectrometer, electron probe micro-analysis, and metallographic analyses. Lead isotope analysis (LIA) was employed to determine the provenance of the metal. The objects are mainly made of tin bronze (Sn 4.1-10.5 wt%) or lead-bronze (Pb 2.5-11.8 wt.%). Segregations or inclusions are observed in the α-phase, mainly mixed sulphides, δ-phase, and lead. The developed database containing chemical and isotopic data of copper mineralizations (Artioli et al., 2020) is used to interpret the LIA results. The finds exhibit various and complex signals of copper or lead sources, principally Iberian Peninsula and Aegean. These preliminary results suggest a complex metal supply strategy in terms of time and location of possible sources, with respect to the simple model of exploitation of regional resources (Cicolani et al., 2023).