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Slices of oceanic lithosphere belonging to the neo-Tethys realm crop out discontinuously in the northern Calabrian Arc, Southern Apennines. They consist of highpressure-low-temperature metamorphic ophiolitic sequences formed from metaultramafics, metabasites and alternating metapelites, metarenites, marbles and calcschist. Ophiolites occupy an intermediate position in the northern Calabrian Arc nappe pile, situated between overlying Hercynian continental crust and the underlying Apenninic limestone units. In the literature, these ophiolitic sequences are subdivided into several tectonometamorphic units. Geochemical characteristics indicate that metabasites were derived from subalkaline basalts with tholeiitic affinity (transitional mid-oceanic ridge basalt type), and a harzburgitic-lherzolitic protolith is suggested for the serpentinites. The pressure-temperature-deformation paths of the metabasites from different outcrops display similar features: (i) the prograde segment follows a typical Alpine geothermal gradient up to a metamorphic climax at 350 ° C and 0.9 GPa and crystallization of the high-pressure mineral assemblage occurs along a pervasive foliation developed during a compressive tectonic event; and (ii) the retrogression path can be subdivided in two segments, the first is characterized by nearly isothermal decompression to approximately 400 ° C and 0.3 GPa and the second follows a cooling trajectory. During low-pressure conditions, a second deformation event produces millimetric to decametric scale asymmetric folds that describe west-verging major structures. The third deformation event is characterized by brittle extensional structures. The tectonometamorphic evolution of the ophiolitic sequences from the different outcrops is similar. Both thermobarometric modeling and tectonic history indicate that the studied rocks underwent Alpine subduction and exhumation processes as tectonic slices inside a west-verging accretionary wedge. The subduction of oceanic lithosphere was towards the present east; therefore, the Hercynian continental crust, overthrusted on the ophiolitic accretionary wedge after the neo-Tethys closure, was part of the African paleomargin or a continental microplate between Africa and Europe.

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The 1:25.000 scale geological map of the central area of Catena Costiera is aimed to provide a picture of the tectonic setting of the metamorphic units belonging to the alpine collisional belt of the Northern Calabria, Italy. The exposed successions of the study area have been investigated by structural analyses, petrographical, petrological and geochemical studies whose results are summarized in the geological map. \ud In this area, two HP-LT metamorphic, oceanic-derived units, referred as the Mongrassano and Cozzo Cervello units, have been distinguished on the base of their stratigraphic and tectono-metamorphic evolution. Both the oceanic-derived units show a polyphase deformation history developed under retrograde metamorphism regarded as achieved in a subduction zone by underplating and exhumation into an accertionary wedge. These units are thrust by continental-derived units, referred as the Sila and Castagna units, consisting of medium and high-grade metamorphic rocks. Whereas the Castagna unit display an alpine HP/LT metamorphic overprint, the Sila unit escaped any subduction-related metamorphism