Inclusions of immiscible sulfide melts in phenocrysts from mantle-derived magmas: Implications for the evolution of sulfide liquids during silicate fractionation

摘要

Sulfide inclusions, droplets of immiscible sulfide melt trapped during crystal growth, have been observed in silicate and oxide phenocrysts of lavas from a variety of tectonic settings, including MORB, OIB, BABB, Island Arc and Continental Flood Basalts, and have, less commonly, been recorded from intrusive suites (e.g., Joslin, 2004). Such inclusions, and in particular those hosted by olivine in volcanic rocks, have the potential to ① provide the only direct evidence for sulfur saturation and the composition of an immiscible sulfide liquid early in the fractionation history of a mantle-derived magma. ② be used to evaluate the compositional variations of immiscible sulfide liquids during silicate mineral fractionation, and ③ provide evidence of systematic compositional variations of sulfide liquids from magmas in different tectonic settings.