Ore lead and sulphur isotope pattern from the low-temperature veins of the Catalonian Coastal Ranges (NE Spain)

The lead isotopic composition of galenas from low-temperature veins of the Catalonian Coastal Ranges (NE Spain) displays a small but distinct range of values: 18.318 less than or equal to (206)pb/(204)pb less than or equal to 18.678; 15.678 less than or equal to (207)pb/(204)pb less than or equal to 15.767 and 38.534 less than or equal to (208)pb/(204)pb less than or equal to 39.189. The data define a linear trend in the (208)pb/(204)pb versus (206)pb/(204)pb diagram that can be interpreted in terms of mixing of lead from different reservoirs. The lead appears to be derived from a solution that preferentially leached granites of Late-Hercynian age. Sulphur isotopic compositions of the galenas range from -8.5 to + 7.3 parts per thousand but variations in a single deposit are small (1-2 parts per thousand), pointing to different sources of sulphur. In a delta(34)S versus (206)pb/(204)pb plot no clear correlation trends appear. Lead isotope data from deposits of similar characteristics situated within the Hercynian orogenic belt as the Linares-La Carolina district (S Spain) and the Inglesiente-Sulcis area (Sardinia) show slight differences indicating a source area of similar lead isotopic composition. In the CCR and Linares-La Carolina districts, the main source of lead is related to the Hercynian granites of each area, although small contributions from metasediments cannot be ruled out. The contribution of lead from metasedimentary rocks is particularly seen in the Sardinian (Hercynian vein-type) ores.