GNGTS 2021 - Atti del 39° Convegno Nazionale

GNGTS 2021 S essione 1.2 120 2001 and 2002-03 eruptions, while maximum restored CO 2 contents reaches 1754 ppm. Degas- sing starting from 300 MPa magmas coupled with CO 2 flushing lead to water depletion in the melt and diffusive water loss from the inclusions, with major effect at pressure below than 200 MPa (Fig.2). The transition from type 1 to type 2 inclusions occurs between 200 and 100 MPa during crystallization of Fo 78 olivine plus clinopyroxene. Inferred high initial water concentrations, com- parable with those measured for products emitted during the highly explosive 2001 and 2002-03 eruptions, reflect the potential for Etna magmas in feeding highly explosive eruptions, which primarily depends on degassing dynamics taking place at shallow levels in the volcano plumbing system under open-system degassing conditions. References Borzi A.M., Giuffrida M., Zuccarello F., Palano M., and Viccaro M., 2020: The Christmas 2018 eruption at Mount Etna: Enlightening how the volcano factory works through a multiparametric inspection . Geo- chem. Geophys. Geosyst., 21, e2020GC009226. Cannata, A., Di Grazia, G., Giuffrida, M., Gresta, S., Palano, M., Sciotto, M., Viccaro, M. and Zuccarello, F., 2018: Space-time evolution of magma storage and transfer at Mt.Etna volcano (Italy). The 2015–2016 reawakening of Voragine crater . Geochem. Geophys., 19, 471–495. Gennaro E., Iacono-Marziano G., Paonita A., Rotolo S.G., Martel C., Rizzo A.L., Pichavant M. and Liotta M., 2019: Melt inclusions track melt evolution and degassing of Etnean magmas in the last 15 ka . Lithos, 324–325, 716–732. Fig.2 - Diagram showing unrestored and restored H 2 O-CO 2 MIs compositions (see color legend) with associated degassing paths calculated using VOLATILECALC (Newman and Lowenstern, 2002).