High-resolution dating of medieval silver-lead mining through integrated archaeological, dendrochronological and dendroanthracological analyses of firesetting remains (Vallauria, Alpes-Maritimes, France)

Abstract

Accurately dating ancient mining activities remains a major challenge, particularly where radiocarbon chronologies lack precision. This study aims to refine the chronology of medieval silver–lead exploitation at the Vallauria mine (Alpes-Maritimes, France) through an integrated dendrochronological and dendroanthracological approach. The analysis focuses on charcoal remains recovered from the “Absides” sector, a mining area located at the south-western end of the medieval extraction front. These remains correspond to in situ residues of firesetting activities used for ore extraction. Several hundred charcoal fragments, mainly conifers (Larch/Spruce and Silver fir), were analysed. Tree-ring series were measured and grouped into eight mean chronologies, which were cross-dated with regional reference datasets to establish terminus post quem (TPQ). In parallel, a dendroanthracological protocol was applied to distinguish branch wood from trunk wood based on ring-width distributions derived from modern reference samples. This distinction enabled the estimation of missing rings in branch fragments using a maximum branch age of 125 years, providing terminus ante quem (TAQ). The results yield several TPQs and TAQs, indicating that the main mining phases occurred between the 12th and early 13th centuries, with a possible extension into the early 14th century. Although some TPQs remain uncertain due to moderate correlations and the specific growth patterns of European larch, combining TPQ and TAQ significantly refines chronological resolution compared to radiocarbon dating alone. The dendroanthracological analysis shows a predominant use of trunk wood, alongside variable contributions of branch wood within firesetting piles suggesting the full exploitation of harvested trees. Despite methodological limitations, this study highlights the strong potential of combining dendrochronology and dendroanthracology to improve the temporal resolution of mining activities and better understand past wood-use practices.

The authors' abstract, as published at the source. Dendrochronologia, 2026 · DOI ↗