Vein-type base-metal ores in Linares-La Carolina (Spain) ore-lead isotopic constrains
European Journal of Mineralogy Volume 4 Number 2 (1992), p. 337 - 344
published: Apr 21, 1992
manuscript accepted: Jun 12, 1991
manuscript received: Jul 20, 1990
ArtNo. ESP147050402019, Price: 29.00 €
Abstract Linares-La Carolina mining district comprises a group of mineralisations of variable ages and styles: Ordovician-Silurian stratiform deposits and Late Hercynian vein and stratabound types. Preliminary Pb-isotope data from the vein-type mineralisations indicate that lead from upper crustal rocks (likely Palaeozoic metasediments) was remobilised and redeposited in vein-type deposits during the Permian-Triassic mineralisation event. Incorporation of varying amounts of Late Hercynian granitoid-derived lead can not be ruled out. μ2 and K isotopic ratios above the average in orogenic settings reflect U-Th "enriched" rocks relative to non-radiogenic lead probably as consequence of a crustal evolution with several stages of Pb-depletion. Even if some 238U depletion could occur, the 238U abundance relative to 204Pb was high enough to keep μ2 > 10.5 after the depletion.