Geochemistry and tectonic setting of the Upper Cretaceous volcanics from Capo San Vito Peninsula (Western Sicily, Italy)

Abstract

Petrological and geochemical data of the Upper Cretaceous volcanic rocks from Western Sicily are here reported with the aim to provide new information about the African paleomargin magmatic activity before the onset of the Alpine Orogeny. The studied alkaline basalts and basanites/nephelinites crop out as pillow breccias interbedded within the carbonate platform sequence of the Capo San Vito Peninsula. Abundances and ratios of incompatible elements resemble OIB-type volcanics from intraplate environment. They were generated from a low partial melting degree of a mantle source located in the transition zone between garnet- and spinel-lherzolite fields. Comparison with literature data of the coeval Hyblean volcanics show similar geochemical features of a plausible common source for the anorogenic magmas involved in their genesis. The Cretaceous magmatism of the S. Vito Lo Capo Peninsula is the result of magmatic intrusions in response to the extensional tectonic regime of the African plate northern edge.