The Villa Senni Eruption (Alban Hills, central Italy): the role of H2O and CO2 on the magma chamber evolution and on the eruptive scenario

Carbon dioxide in silica-undersaturated melt. Part I: The effect of mixed alkalis (K and Na) on CO2 solubility and speciation

“…Eggler, 1974;Green, 1975, 1976;Wallace and Green, 1988;Falloon and Green, 1989;Hirose, 1997;Freda et al, 1997;Draper and Green, 1997;Dalton and Presnall, 1998). Carbon dioxide (CO 2 ) is the second most abundant magmatic volatile (e.g.…”

New physical characterization of the Fontana Lapilli basaltic Plinian eruption, Nicaragua

“…These eruptions had mass eruptive rates of 0.7-2.0 × 10 8 kg s −1 . Several studies indicate that highly explosive eruptions can also occur with fluid magma not specifically of basaltic compositions (Freda et al 1997;Palladino et al 2001;De Rita et al 2002;Watkins et al 2002;Sulpizio et al 2005). The recognition that many volcanoes occasionally erupt low-viscosity magma in such a powerful sustained fashion has come at a time when urban growth and volcano tourism bring increasing numbers of people to volcanoes such as Alban Hills, Etna and Vesuvius (Italy), Tarawera (New Zealand) and Masaya (Nicaragua; Chester et al 2002).…”

The Vesuvius and the other volcanoes of Central Italy

“…Geochemical and petrological studies indicate that the largest influence on the Colli Albani magma chemistry is associated with the mantle source regions, where different degrees of partial melting of metasomatic veins and surrounding mantle peridotite control the observed magma composition Conticelli et al, 2010a,b). Differentiation and crustal assimilation also played a role at shallow magma chamber level (Freda et al, 1997(Freda et al, , 2008Dallai et al, 2004;Gaeta et al, 2006Gaeta et al, , 2009Gaeta et al, , 2011Boari et al, 2009b;Sottili et al, 2009;Di Rocco et al, 2012). In spite of its very silica poor compositions (SiO 2 between 43 wt.% and 54 wt.%), the volcano displays several features identical to felsic volcanoes, including low aspect ratio ignimbrites tens of cubic kilometres in volume, and a related central, polyphased collapse caldera about 10 km x 10 km in morphological diameter (Fig.…”

“…These features are the major difference with other Roman volcanoes of the Latian districts, where ignimbrites have invariably phonolitic to trachyphonolitic compositions. Such mafic chemical characteristics of the magmas involved in Colli Albani ignimbritic eruptions were thought to represent a problem due to the possible lack of volatiles necessary to trigger paroxysmal eruptions (Freda et al, 1997. To tackle this issue, carbonate syntexis has been suggested to supply the needed CO 2 to trigger paroxysmal eruptions (e.g., Freda et al, 2007;Iacono Marziano et al, 2007, 2008Gaeta et al, 2009), although such a process would have enriched the CaO and dramatically diluted the MgO and incompatible trace element contents of the magmas (Peccerillo, 1998(Peccerillo, , 2004(Peccerillo, , 2005b, features that are not observed in Colli Albani rocks .…”

“…By contrast, the upper ignimbrites (i.e., pozzolane nere, pozzolane rosse and Villa Senni ignimbrites) are typically 10-80 m thick scoria and ash flow deposits. Detailed descriptions of most of these ignimbrites can be found in several papers (Fornaseri et al, 1963;Giordano & Dobran, 1994;De Rita et al, 1995;Freda et al, 1997Freda et al, , 2011Palladino et al, 2001;Watkins et al, 2002;Giordano et al, 2006aVinkler et al, 2012). Extensive lava flows interbedded within the main ignimbrites formed large plateaux such as the Vallerano and the San Vittorino lavas (ca.…”