10:15 AM - 10:30 AM
[PPS10-12] Melting and quench experiment of iron sulfide fine particles at atmospheric entry
Keywords:troilite, micro meteorit, Fe-S-O system, magnetite, atmospheric heating
Run products with rounded shape and smooth surface show that the particles were completely melted. Chemical compositions of particles analyzed on cross sections are generally well homogenized from heterogeneous starting materials by complete melting. Molar ratios of Fe in melted regions are close to 0.5, while compositions of S and O are various. Varieties of S and O compositions show various degree of oxidation and evaporation of sulfur. Distribution of compositions of melted regions in Fe-S-O system is plotted in liquidus compositions of FeO and FeS saturated melt. Compositions of FeS melt in fine spherules are following Fe-S-O phase relations even in a few seconds. Evaporation of sulfur from meteoritic materials in atmospheric entry heating may depend on oxygen fugacity of the upper atmosphere. Sulfur supply from meteoritic materials to atmosphere may be limited on planets with oxygen-free atmosphere.