Experimental Melting of Carbonated Peridotite at 6-10 GPa

2007/10/11 by G. P. Brey, Gerhard P. Brey, V. K. Bulatov +3 · 3 citations
Earth and Planetary Sciences · #Geological and Geochemical Analysis #High-pressure geophysics and materials #earthquake and tectonic studies

paper · doi:10.1093/petrology/egn002

Abstract

Partial melting of magnesite-bearing peridotites was studied at 6¹0 GPa and 1300¹7008C. Experiments were performed in a multianvil apparatus using naturalmineralmixes asstartingmaterial placed into olivine containers and sealed in Pt capsules. Partial melts originated within the peridotite layer, migrated outside the olivine container and formed pools of quenched melts along the wall of the Pt capsule. This allowed the analysis of even small melt fractions. Iron loss was not a problem, because the platinum near the olivine container became saturated in Fe as a result of the reaction Fe2SiO4 OlFeFe^Pt alloyþFeSiO3OpxþO2.This reaction led to a gradual increase in oxygen fugacity within the capsules as expressed, for example, in high Fe3þ in garnet. Carbonatitic to kimberlite-like melts were obtained that coexist with olivineþ orthopyroxeneþ garnet clinopyroxenemagnesite depending on P^T conditions.

Cited by

• The composition of near-solidus melts of peridotite in the presence of CO2 and H2O between 40 and 60 kbar
• Experimental constraints on mantle metasomatism caused by silicate and carbonate melts
• Sulfide-rich continental roots at cratonic margins formed by carbonated melts

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