Podiform chromitites from the Calzadilla de los Barros serpentinite, Iberian Massif, SW Spain

Abstract

Podiform chromitites occur as in situ and removed bodies in the Calzadilla de los Barros Serpentinite (Iberian Massif, SW Spain), a set of ultramafic massifs made up of partly serpentinized harzburgite with minor dunite and gabbros. They consist of massive to semi-massive chromitites, frequently with nodular texture. Chromite chemistry is characterized by high Al2O3 contents and up to 0.4 wt.% TiO2, in agreement with a MORB affinity of the parental melt. Platinum-group element abundances are similar to most Al-chromitites reported in the literature except for an unusual enrichment in Pt and Pd. High Pt and Pd values were probably caused by late metamorphic alteration.