Rare earth and trace element characteristics of ophiolitic metabasalts from the Alpine-Apennine belt

The Western Mediterranean Jurassic ophiolites contain abundant volcanic rocks that resemble modern ocean floor basalts. In this paper we report analyses of rare earth elements (REE), transition elements (Ni, Co, Cr, V, Sc) and high field strength elements (Ti, P, Y, Zr, Ta, Hf) for metabasalts from representative ophiolite outcrops in the Eastern Alps, Corsica and the Northern Apennines (Liguria).The chemical characteristics of the metabasalts range from “normal” to “transitional” mid-ocean ridge basalt (MORB). Most chemical variation in the metabasalts from the different areas can be explained by low-pressure fractional crystallization, by differences in degree of partial melting, and by minor chemical heterogeneities of the source, but the “transitional” MORB characteristics of some metabasalts from Corsica (Balagne) might reflect formation from a source with different mineral and chemical composition. The estimated REE pattern of the source of the Liguria-type metabasalts corresponds to the pattern for certain Ligurian ultramafic rocks, which might therefore represent the residue from extraction of some ophiolitic lavas.While the Liguria-type ophiolitic metabasalts might represent products of a “normal”, for instance, oceanic ridge, the “transitional” metabasalts might be lavas erupted, during the early stages of opening of a small ocean basin, or along the continental margin of a larger ocean basin.