Platinum and palladium have been detected in sulfide bearing gabbros from the classic Troodos ophiolite complex of Cyprus, Concentrations of the platinum-group elements (PGE) in the Troodos gabbros give positively sloping chondrite-normalized pattems. Os, Ir and Ru are removed from the magma at an early stage, with chromitites, which have a negatively sloping chondrite-normalized pattern. Pt and Pd are fractionated to higher levels within the magmac hamber, and are concentrated at the base of the gabbros, but they also occur at higher stratigraphic levels in the gabbros. The PGE in fresher gabbros retain their magmatic chondrite-normalized patterns, though located in secondary platinum arsenide and palladium antimonide associated with actinolite. Evidence from the "type" ophiolite complex, on Troodos, supports the idea that significant levels of Pt and Pd are generally present in ophiolites.
|Publication status||Published - 1990|