Reduced magmatic fluids in basalt from the island of Disko, central West Greenland

摘要: Abstract Fluid and melt inclusions in minerals of two native iron-bearing dyke rocks from Disko, Greenland, were investigated using heating cooling microscopic techniques. The olivine are homogenized at temperatures 1170–1200 °C. melts characterized by high SiO 2 , K O TiO low MgO contents. co-existence combined melt–fluid (gas) implies that the phenocrysts crystallized a heterogeneous magma pressure. Gas bubbles glass rock. Water four crystalline phases observed room on walls bubbles: serpentine, naphthalene, clathrate, an unknown phase. complex composition trapped volatiles is reflected considerable ranges clathrate melting solidus (20 to 7.5 °C −82.6 −73 °C, respectively). Melt equilibrium with metallic iron T =1450 suggests log f =−13.95. calculated C–O–H fluid Fe, Fe 3 C FeS CH 4 H During postmagmatic stage, polymerization proceeds, heavy hydrocarbons formed inside vesicles. presence organic compounds magmatic stage natural consequence unusual reducing condition during crystallization.