Radiocarbon measurements of iron girders from Aachen cathedral

Radiocarbon dating of iron girders from Aachen Cathedral reveals that the Carolingian Palace Chapel's construction dates between CE 793 and 813, aligning with historical records. The study demonstrates the reliability of this method for ancient iron, though it highlights challenges due to contamination from exogenous carbon sources such as old wood, flux additives, or modern reconstruction materials. Notably, iron beams from the Gothic Annex showed variable radiocarbon signatures, likely due to medieval forging techniques and recent welding with fossil carbon. The research also compared iron dates with those of contemporary wood and charcoal, providing a robust age reference framework.

Hüls, C. M. (2025). Radiocarbon measurements of iron girders from Aachen cathedral. Folia Quaternaria, 92, 79–90. https://doi.org/10.4467/21995923fq.24.004.21036