Estudio de la composición isotópica (Pb-S-O) de las mineralizaciones Pb-Zn de Mazarambroz (Banda Milonítica de Toledo)

Combined lead, sulphur and oxygen isotopes have been analysed in ore (galena and sphalerite) and associated (quartz, barite) minerals from the Mazarambroz Pb-Zn mineralization. Lead isotopic model ages in galenas cluster around 121 ± 8 Ma in good agreement with previously suggested mesozoic age of this Pb-Zn mineralization estimated by apatite fission tracks in mylonitic wall-rocks. Isotopic composition of Mazarambroz mineralization suggests a high rock (metamorphic/granitic)/fluid interaction with minor participation of meteoric waters. These fluids circulated deeply along fragile cracks of the major shear zone of Toledo