AMALIA, A Matching Algorithm for Lead Isotope Analyses: Formulation and proof of concept at the Roman foundry of Fuente Spitz (Jaén, Spain)

Abstract

This article presents A Matching Algorithm for Lead Isotope Analyses (AMALIA) that yields analytical coincidences in lead isotope databases, allowing a fast selection of potential candidates for metal provenance. As a proof of concept, potential ore sources for 29 Roman lead artifacts from the archaeological site of Fuente Spitz (Jaén, Spain) are provided. Additionally, a reassessment of legacy, TIMS lead-isotope analyses is conducted by re-analysis of 26 galena samples from nearby mining districts by MC-ICP-MS. The study demonstrates the accuracy and reliability of AMALIA and stresses the need to assess the isotope ratio data obtained without lead isotopic tracers (spikes) by TIMS carefully on a case-to-case basis. At the archaeological level, our study shows that the foundries and smelting sites at Fuente Spitz and Cerro del Plomo processed galena ores from the mining districts of La Carolina and Linares to produce a variety of lead products and lead ingots that have been found at several places thorough Europe, thereby providing tangible evidence of the regional and long-distance commercial circuits that these foundries were supplying.