An assessment of copper mineralization from the Great Orme Mine, Llandudno, North Wales, as ore in the Bronze Age

Spoil heap and in situ mineralization from the Great Orme Mines, North Wale s, have been classified into six mineral associations. By applying mineralo gical, mining and beneficiation criteria, their probable exploitation as co pper ores in the Bronze Age have been assessed. Major veins and open voids within dolostones are infilled by saddle dolomite-chalcopyrite-pyrite-calci te-malachite. The tonnage, estimated copper grade of 10% and continuity of the veins, plus the coarse grain-size of the copper bearing minerals, sugge st that the veins were mined in the Bronze Age possibly accompanied by cont ributions from adjacent void-infilling mineralization. Two minor types of m ineralization, namely 'copper ddu ore', a very fine-grained, friable, limon itic vein-infilling, and disseminated, c. 1 cm diameter, azurite nodules in mudstones, may have been taken as a by-product of other mining operations. Neither the fine-grained, disseminated, Cu-, Pb-, Fe-, Co-, Ni-rich, polym etallic sulphides, which are only found in dolostones from the spoil, nor t he single, copper-poor, but galena-rich assemblage found as a vein-infillin g, can be considered to be Bronze Age copper ores. These last two associati ons belong to the Mississippi Valley-style lead-zinc mineralization of the North-east Wales Orefield that is older in age and differently sourced from the copper-dolomite association ores that produced Bronze Age copper metal . The recognition and sampling of ores, rather than mineralized specimens, from a mine site, have implications for geochemical or isotopic provenance studies that lie far beyond the Great Orme. This is because only run-of-the -mill ores should be treated as having any importance to archaeometallurgis ts.