Estudio de la composición isotópica del Pb en galenas del distrito minero de Linares-La Carolina (Jaén, España)

Abstract

New lead Isotope results for twenty-four galenas of the Linares-La Carolina mining district (Jaén, Spain) are reported. While two.mineralization types, one near Linares (where filons with low Ag content crosscut the Linares and/or Guadalén-Arquillos plutons) and another at La Carolina (Ag-rich filons cut the Santa Elena granite or its host-rocks) may be distinguished, the Pb isotopic compositions of the galenas from both areas are similar and very homogeneous: mPbl204Pb = 18.236 ± 0.036, 207Pb/204Pb = 15.615 ± 0.014 and 208Pb/204Pb = 38.347 ± 0.046, giving a model age of 324 ±18 Ma. These results are very different from the Pb isotopic compositions and model ages recorded on galenas from the nearby El Zumajo vein within the Los Pedroches batholith main body. Notwithstanding, since the p2 calculated values from El Zumajo and Linares-La Carolina district are very similar, it is argued that a genetical relationship must exist between the mineralizations of the Los Pedroches batholith and those of Linares-La Carolina. The observed differences in isotopic ratios might reflect two, at least, different events of mineralization