Melting temperatures were experimentally determined for the lava of Màscali (Etna), erupted in 1928. The lava is an "olivin andesine basalt". The melting point was established with the quenching method after the runs were equilibrated in current of air, of CO2 and of different constant ratios of H2 and CO2: this in order to define the influence of the oxygen partial pressures on the melting temperatures of the lava. The experimental data demostrate that those values are very close to a linear relationship $-\log p_{O_{2}} = A/T - B$ where A = 21,80 and B = 141,5226. The first appearance of crystals shows a metallic phase in the runs carried out in air and in CO2 and a silicate phase in the runs carried out in more reducing atmospheres.
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Con il contributo del Ministero per i Beni e le Attività Culturali