Reduced Fluids and Sulfide–Metal Alloy in the Magnesian Basalts of Disko Island, West Greenland

摘要: This paper presents the results of a combined study composition and physical properties fluid, melt opaque mineral inclusions in olivine phenocrysts glass from magnesian basalt Disko I., West Greenland. The rock is dominated by glass, which contains numerous fluid bubbles large (up to 250 μm) globules. thermometric investigation showed that temperature crystallization was no higher than 1220°C at pressure 0.15–0.20 GPa. globules groundmass have eutectoid structure are composed troilite, Fe–Ni metal alloy, sparse grains wustite cohenite (Fe3C). Cryometric measurements Raman spectroscopy indicated complex presence reduced oxidized gases: CH4, N2, H2, CO2, H2O, as well highly ordered graphite. nonequilibrium association compounds related rapid cooling (quenching) crystallizing magma preventing equilibration gas system. At an estimated logfO2 value –13.95, methane only hydrocarbon phase can exist magmatic temperatures. formation organic substances detected some glasses occurred postmagmatic stages after significant decrease temperature.