Geological and Mining Constraints on Historical Mine Production: The Case of Early Medieval Lead-Silver Mining at Melle, France
L. F. Bettenay
Early Medieval silver production for the Melle Pb-Ag deposit in western France has been estimated up to 15 tonnes per year over hundreds of years (Téreygeol, 2013) which would place it amongst top mines all times prior New World discoveries. However, this geological and mining characteristics economically unsuitable substantial production, because is thin, sub-horizontal comprised discontinuous pods. Furthermore, a Mississippi Valley type (MVT) base metal deposit, are typically not major producers. There no evidence primary or secondary enrichment generate silver-rich ore. Inaddition, fact that remained unmined later historical periods enigmatic compared almost ubiquitous reworking significant ore deposits elsewhere.In paper, I discuss characteristics, parameters, documented rates workforce considerations, can be used constrain estimates Melle. The largest uncertainty size, reflects scarce information about Carolingian its surroundings. A model employing realistic parameters appropriate small village (100 miners/fire-setters, within 250-300, from settlement at least 400-500) yields 52 lead 150 kg year. Doubling double estimate. Conversely, could half less if was seasonal activity between agricultural priorities such as harvesting seeding.The previously claimed require improbable assumptions together with 500 dedicated full-time miners population thousands. yield capita productivity more than four higher well-documented Modern operations were leading their time. This seems unlikely. even much lower levels, favoured here, still might have factor economy, perhaps important silver.
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