The island of Linosa (Sicily channel)

The volcanology and petrology of Linosa island are described. Linosa and Pantelleria are two quaternary volcanic islands located in the Sicily Channel, a NW-SE elongated continental rift structure of the southern Mediterranean Sea. Several hyaloclastitic rings mark the period of submarine explosive activity which formed Linosa. Lava flows and spatter cones, originated in a later period, prevented the complete destruction of this island by the sea. A typical (undersaturated) alkali basalt fractionation trend has been recognized at Linosa while Pantelleria is characterized by diflerentiation products originated from a mildly alkalic-transitional basaltic magma. These petrogenetic differences between Linosa and Pantelleria have tentatively been related to a different crustal thickness of the islands due to their tectonic location within the Sicily Channel: Linosa on a marginal area, Pantelleria just on the axis of a graben. The genesis and evolution of the Sicily Channel Rift Valley and of the associated basaltic magmatism are probably related to tensional stresses affecting the northwards migrating African plate, just behind its contact zone with the Eurasian plate.