New petrological data for the Mt Iblei volcanic rocks, southeast Sicily: genetic and geotectonic implications)

During the Cretaceous, Miocene and Plio-Quaternary time the SE Sicily was affected by widespread volcanism. Cretaceous volcanic rocks outcrop in the southern part of Sicily. They consist of basaltic flows, sometimes subaqueous, with a dominant alkaline character. Upper Miocene volcanism is characterized by numerous subaqueous eruptive centres, comprising volcaniclastic deposits interbedded with carbonate sediments. Alkaline and subalkaline magmas were contemporaneously erupted. In the Middle Upper Pliocene sequence alkaline and tholeiitic basalts are interbedded in a thick sequence of subaereal lava flows. Geochemical data suggest that the alkaline rocks could be derived by 4% and 10% of partial melting, whereas higher degrees of partial melting (35%) are necessary for the tholeiitic basalts. The association between alkaline and tholeiitic basalts can be related to the tectonics of eastern Sicily. -English summary