Tracking the source of lead of medieval glazed pottery of the Meuse valley (Belgium) through lead isotope analyses

Lead isotope analyses (by MC-ICP-MS) have been performed on lead-glazed pottery artefacts from several production and consumption sites in the Meuse basin (Belgium) spanning a long-time period from the 9th to the 16th century CE. Comparison of the lead isotope data of the glazes from three Mosan workshops with those of galenas from Palaeozoic (Variscan) Pb-Zn deposits from both Belgium and Western Germany points to a common Pb source that we identify as the regional Pb deposits hosted in Dinantian limestones of the Ardenno-Rhenish Massif, more specifically in the Namur and Verviers synclines in Belgium and in the Aachen-Stolberg mining district in Germany. The overall similarity of isotopic compositions between the medieval artefacts and the Variscan galenas implies that the Mosan medieval potters used accessible local Pb-Zn ores mined between Namur and Huy. On the consumption sites of Dinant, the slightly different isotopic compositions of some potteries suggest that other regional Pb sources were used to produce the glazes. A comparison with Roman lead objects discovered in north-western Europe (Northern Gaul) shows the very good correspondence of the Pb isotopic compositions with those of the Medieval artefacts which indicates a very long continuity of regional lead supply and consequently of lead ore mining.