Vein-type base-metal ores in Linares-La Carolina (Spain); ore-lead isotopic constrains

This mining district comprises a group of mineralizations of various ages and styles, including Ordovician-Silurian stratiform deposits and late Hercynian vein and stratabound types. Preliminary Pb-isotope data from the vein-type mineralizations indicate that Pb from upper crustal rocks (probably Palaeozoic metasediments) was remobilized and redeposited in vein-type deposits during the Permian-Triassic mineralization event. Incorporation of varying amounts of late Hercynian granite-derived Pb cannot be ruled out. High mu (sub 2) and K values ( (super 238) U/ (super 204) Pb >= 10.5 and (super 232) Th/ (super 238) U >= 4.2) reflect U-Th 'enriched' rocks relative to non-radiogenic lead and may result from crustal evolution with several stages of Pb depletion.