Mantle peridotites and cumulates from the Elba Island ophiolites: fragments of the oceanic mantle-crust transition zone

The ophiolites of the Elba Island have been correlated with the other Mesozoic ophiolites of the Northern Apennines, in particular they have been related to the Internal Ligurides which represent sub-oceanic mantle-derived peridotites. In eastern Elba, ophiolites consist of several tectonic slices composed by serpentinized peridotites, gabbros, mafic-ultramafic cumulates, and volcanic basalts which are overlain by thick sedimentary formations of Mid-Late Jurassic to Cretaceous age. This paper contains a short description of the petrographic and microchemical features of the ultramafic/mafic ophiolitic sections cropping out in the Sassi Turchini, Rio nell'Elba and Rio Marina areas. The results are discussed on the basis of the most recent hypotheses regarding the evolution of the present-day oceans.