Mineralogy and Lead Isotope Signature of the Gold and Silver Ores Used during the Roman Era at Alburnus Maior (Ro?ia Montanà, Romania)

Alburnus Maior (Rosia Montană, Romania) was an important precious metals mining site during Roman times. Geological, ore deposit and geochemical studies have been carried out on the ore bodies exploited during the Roman period that have been discovered during archaeological excavations. The primary purpose of the present paper is to demonstrate the importance of the study of geologically and chronologically referenced ores by means of mining archaeology and geology for identifying the sources of precious metals from Roman Antiquity.The geological studies carried out in the Cârnic Massif allowed the identification of four mineralisation phases. Three of these four phases have been exploited by the ancient miners. Each mineralised phase is characterised by a specific precious metals mineral association, and two of them contain rare Te and Ge bearing minerals. As their elemental composition is heterogeneous, the use of lead isotopes represents a good methodology for refining their characterisation. Each mineralised phase has its own lead signature. In spite of some observed differences in terms of lead isotopes for each phase, the overall signature of Rosia Montană (RM) displays a well defined isotopic field. When compared to other mining districts in Romania, the isotopic field of RM is distinguishable, and this allows a better discrimination that can contribute to the provenance study of minerals from Eastern Europe.