作者: Fabio Arzilli , Paola Stabile , Alessandro Fabbrizio , Patrizia Landi , Bruno Scaillet
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摘要: Peralkaline rhyolites, associated with extensional tectonic settings, are medium to low viscosity magmas that often produce eruptive styles ranging from effusive highly explosive eruptions. The role of pre-eruptive conditions and crystallization kinetics in influencing the style peralkaline rhyolitic has been investigated debated considering equilibrium conditions. However, experimental constraints on effect disequilibrium such currently lacking literature. Therefore, we performed isobaric cooling experiments investigate alkali feldspar melts. Experiments were under water-saturated, water-undersaturated anhydrous between 25 100 MPa, at 670-790 °C durations 0.5 420 hours. Here present first data feldspar, which is main crystal phase melts, order improve our understanding evolutionary timescales these melts their ability shift activity. Our results indicate nucleation delay can range hours several days as a function undercooling H2O content melt. Thus, magma be stored for without important variations its fraction. This suggests may not necessarily play triggering fragmentation during eruptions magmas.