Vincoli biostratigrafici sull’età del vulcanismo alcalino paleozoico dei Monti Peloritani (Sicilia nord-orientale).

The Palaeozoic successions of the Longi-Taormina Unit (Peloritani Mountains, North-Eastern Sicily) are mainly formed by slightly metamorphosed siliciclastic sequences, containing at different stratigraphic heights Upper Ordovician acidic rocks and undated alkaline volcanic layers. These Palaeozoic successions are locally capped at the top by fossiliferous calcareous beds. A detailed biostratigraphic study on conodonts yielded by these carbonates has revealed an Upper Silurian-Lower Devonian age for this interval. These new biostratigraphic data are very useful as they permit to establish that some of the undated alkaline volcanic layers, being overlain by Upper Silurian-Lower Devonian conodont-bearing metalimestones, are surely related to a volcanism not younger than the Late Silurian-Early Devonian and presumably Silurian in ag