Petrogenesis of the Refahiye Ophiolite and its Tectonic Significance for Neotethyan Ophiolites Along the Izmir-Ankara-Erzincan Suture Zone

The Refahiye ophiolite, situated near Erzincan in the eastern part of the Izmir-Ankara-Erzincan Suture Zone (IAESZ), is one of the best exposures of oceanic lithosphere in the northern branch of the Neotethyan Ocean. The ophiolite, mainly thrust southwards, transported on an ophiolitic melange, over the Early Triassic-Campanian Munzur Limestone of the Anatolide-Tauride Platform, was also emplaced by north-directed backthrusting onto the Pontides in the Late Cretaceous. It displays an almost complete ophiolite series unconformably overlain by Tertiary volcano-sedimentary units. The mantle peridotites are dominated by harzburgites, with dunite bands and lenses locally cut by isolated diabase dykes, whereas the mafic-ultramafic cumulates of the mantle-crust transitional zone consist of dunites, wehrlites, pyroxenites and gabbros. The diabase dykes of the sheeted-dyke complex show a magmatic boundary with the underlying massive gabbros which are in places crosscut by plagiogranite dykes. The basic and leucocratic rocks exhibit greenschist facies assemblages of ocean floor metamorphism. The spilitic pillow basalts and cover sediments (radiolarites, pelagic limestones) of the upper units of the oceanic crust are preserved as megablocks in the ophiolitic melange.