| Abstract: | Volcanic rocks from three Palaeozoic low-grade metamorphic sequences of different age from the Peloritan Mountains, Sicily, have been analysed for major and trace elements. On the basis of the relative abundances of certain comparatively immobile elements (especially Zr, Ti, Nb, and Y) the petrogenetic affinities of the volcanic rocks in each area have been established. The Fiumara Fitalia sequence contains Lower Devonian within-plate alkaline basalts, the Ogliastrello sequence contains Upper Devonian continental within-plate calc-alkaline basalts and the Randazzo-Floresta road sequence contains Lower Carboniferous calc-alkaline basalts probably of island arc affinity. When account is taken of their stratigraphic positions, geochemical characteristics of the volcanic rocks indicate Devonian extensional conditions and Lower Carboniferous compressional conditions. Evidence for Lower Devonian extension is present in several circum-Mediterranean basins (i.e. Calabria, Sardinia, Carnic Alps). In the Peloritan Mountains, as well as in Calabria and Sardinia, extensional conditions were already present in the Cambro-Ordovician. The compression in the Calabrian-Peloritan Arc was probably related to a period of subduction during the Hercynian orogeny and resulted in the closure of the basins in the Carboniferous. |
