TRIASSIC ANDESITIC TUFFITES IN THE CATENA COSTIERA (SOUTHERN ITALY). GEOLOGICAL-PETROLOGICAL CHARACTERS AND POSSIBLE GEODYNAMIC IMPLICATIONS

ABSTRACT:Andesitic tuffites of Upper Triassic age (Rhaetian) are reported from carbonate platforms exposed in tectonic windows along the “Catena Costiera”, west of Cosenza. These tuffites, described here for the first time, are interbedded in an evaporitic sequence and represent a distinctive character, relative to the other platforms of the “Appennino Calcareo” (African continental margin) to which they have been associated so far.REE and other immobile elements and their primary mineralogy indicate that the investigated tuffites are of andesitic composition and calcalkaline affinity.The geodynamic significance of these orogenic volcanics is discussed in the geotectonic environment and in the magmatic context of the “Neo-Tethys”, generally accepted as an anorogenic setting.A possible hypothesis, needing more geological data, is that a subduction margin of the Palaeo-Tethys is considerably more displaced to the South-West and also a more westerly prolongation of the Palaeo...