A tentative pre-Variscan geodynamic model for the Palaeozoic basement of the Peloritani mountains (Sicily): evidence from meta-igneous products

Although the metavolcanics interbedded in the Palaeozoic basement of the tectonic units constituting the Peloritani belt show various and contrasting geodynamic affinities,. these rocks are the only record allowing us to establish the chronology of the extensive and compressive events which developed prior to the Hercynian orogenesis. For this reason, their study becomes very important in reconstructing a pre-Hercynian geodynamic model for the Peloritani area. This paper examines two of the most important metavolcanic successions, outcropping in the southern sector of the Peloritani belt. Geochemical analyses, carried out on these two metavolcanic successions, reveal different magmatic affinities: the first succession, Early Ordovician in age, has an alkaline basaltic composition and withinplate affinity; the second, Late Ordovician in age, consists of metavolcanics with orogenic affinity. Taking into account these different geochemical features, the present paper proposes a preliminary geodynamic model for the Palaeozoic basement of the Peloritani plate, spanning an interval from Late Cambrian- Early Ordovician to Late Ordovician.