Somma volcano

Vesuvio lavas younger lhan 1631 AD Somma volcano ... 

Volcano Somma-Vesuvio Age 30 ka to 1944 AD Volcanology and Petrology - Stratovolcano (Mount Somma) with multiple caldera and an intracaldera cone (Vesu-vio) formed of slightly to strongly silica undersaturated trachybasalt and leucite-tephrite to trachyte and phonolite. 

Fig. 6.3. Sketch map of Somma-Vesuvio volcano. Simplified after Civetta et al. (2004).

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. 

Rittmann A (1930) Geologie der Insel Ischia, Zeitschr Vulkanol 6 265 pp Rittmann A (1933) Die geologische bedingte evolution und differentiation des Somma-Vesuvius magmas. Zeitschr Vulkanol 15 8-94 Robin C, Colantoni P, Gennesseaux M, Rehault JP (1987) Vavilov seamount a mildly alkaline quaternary volcano in the Tyrrhenian Basin. Mar Geol 78 125-136... 

Paone, A., Ayuso, R. A., and De Vivo, B. (2001). A metallogenic survey of alkalic rocks of Mt. Somma-Vesuvius volcano. Mineral. Petrol. 73, 201-233. 

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