Experimental and thermodynamic constraints on mineral equilibrium inpantelleritic magmas

摘要: Abstract Crystallization experiments on two pantellerites from Pantelleria, Italy, provide new evidence for the relationships between mineral phases in pantelleritic rocks as well influence of temperature and redox conditions assemblages. Experiments were performed at 1 kbar with ranging 750–900°C, fluid saturation XH2O (=H2O/H2O+CO2) 0 1. Redox fixed at, or slightly below, FMQ buffer. Results show that 900 °C magmas are above liquidus regardless their water content; we also observed a decrease (800°C) increasingly reducing conditions. Mineral assemblages natural have been successfully reproduced, particularly relationship fayalite aenigmatite, which appear to be strongly controlled by melt peralkalinity, This is first time fayalitic olivine synthetized experimental studies pantellerites, was found stable only temperatures ≥750°C while amphibole can high 800°C fF2. Experimental results compared composition obtained equilibrium, geothermometry, oxygen barometry lava tuffs Pantelleria (Italy), Eburru (Kenya) Menengai (Kenya). Petrological characteristics similar different locations worldwide, typical anorthoclase sodian clinopyroxene variable fayalite, Fe-Ti oxides amphibole.