Petrogenesis of Campania, Pontine and Vulture magmas

The volcanoes in the Campania Province, Pontine Islands and Vulture are composed of a wide variety of magma types. Silica undersaturated ultrapo-tassic volcanism is restricted to Somma-Vesuvio, whereas mildly undersaturated to oversaturated potassic rocks occur at Campi Flegrei, Ischia, Procida and Ventotene. In the latter two islands, low potassium compositions close to calc-alkaline basalts are found among lavas and lithic ejecta. Pliocene calc-alkaline rocks are found as rhyolites at Ponza and as basalts and basaltic andesites beneath the Campanian Plain. At Vulture, volcanism is highly enriched in both Na and K, a composition that is distinct from any other volcano in the Italian peninsula. 

An important feature of magmatism in Campania is that the Campi Flegrei mafic rocks are moderately potassic in composition but have very similar concentrations and ratios of several incompatible elements as the ultrapotassic rocks from Somma-Vesuvio these, however, contain higher concentrations of K and Rb (e.g. Peccerillo 2001). In other words, the positive correlation between potassium and incompatible elements observed in other Italian volcanic districts (e.g. Emici and Roccamonfma) is not so evident in Campania. 

Radiogenic isotope data have added important information on evolution of mantle sources. The continuous trends of Sr-Nd-Pb isotope ratios along the Italian peninsula, from Etna-Iblei to Tuscany, have been interpreted as a result of contamination of upper mantle by different types of upper 

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