Minerales del grupo del platino y fases asociadas en el depósito de Ni-Cu-(EGP) de Aguablanca, SW España

Abstract

Aguablanca is a Ni-Cu-(PCE) sulphide mineralization associated to mafic facies of the Santa Olalla hercynian intrusion. The sulphides occur as disseminated ore, massive ore and brecciated ore related to gabbros, norites and minor piroxenites and peridotites. Sulphide mineralogy includes pyrrhotite, pentlandite, chalcopyrite and pyrite. The study of polished samples by scanning electron microscopy has enabled to identify discrete platinum group minerals for the first time in the Aguablanca mineralization. The major platinum group minerals (PCM) are palladium- and palladium-platinum-bearing tellurides such as michenerite (PdBiTe), merenskyite (PdTej, palladian melonite ((Pd, N'OTeJ and members of the solid solution series merenskyite-moncheite (PdTe2-PtTeJ. Sperrylite (PtAsJ is the other main Pt-bearing mineral. Phases containing other platinum group elements are rare and include a Os-lr-bearing sulphoarsenide (irarsite?). Associated minerals include native gold, tellurobismuthite (BiJeJ, bismuthite (Bi2Sj, hessite (Agje), volynskyite (AgBiTeJ and galena. This PCM assemblage is typical of intramagmatic sulphide deposits related to gabbroid rocks.