Late-Hercynian post-collisional dyke magmatism in central Calabria (Serre Massif, southern Italy)

Widespread late- to post-collisional magmatism occurred in the Calabria-Peloritani Orogen(southern Italy) during the final stages of the Hercynian Orogeny. In the Serre Massif (centralCalabria), medium- to high-K calcalkaline andesitic to dacitic-rhyodacitic dykes show typicalgeochemical features of subduction-related magmas (LILE and LREE enrichment, HFSEdepletion, peaks at Rb, Pb and Th). The origin of late- to post-Hercynian calcalkaline rocksis usually interpreted in an extensional post-collisional framework, involving thinning of thecontinental lithosphere and progressive passive upwelling of the asthenospheric mantle. Insuch a context, pure mantle, crustal and hybrid melt production likely can occur. The andesiticdykes were produced by partial melting of an enriched mantle source metasomatized by crustalfluids/melts during former subduction and then suffered minor, if any, assimilation of lowercrustal metapelites. Most dacite-rhyodacites were likely derived by hybridization in variousproportions of crustal and mantle melts, whereas pure crustal metasedimentary sources, andmore or less efficient restite unmixing processes, were involved in the generation of the mostsilica-rich rhyodacites.