CAREER: Experimental Studies of Mantle Melting

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This CAREER proposal consists of a program of high pressure experiments aimed at understanding key aspects of mantle melting and a curriculum development project that will use the MELTS algorithm to introduce undergraduate geology, geophysics, and geological engineering majors to forward modeling as a research and educational tool. The experiments include investigation of whether partial melts of garnet pyroxenite interconnect at low melt fraction, improved determinations of the temperature-pressure location of the solidus for dry peridotite and for peridotite with H2O contained within amphibole and within nominally anhydrous silicates, and a study of the relationship between water fugacity and dissolved H2O in water-undersaturated mafic magmas by measuring the H content of olivine equilibrated with silicate liquids at pressures up to 5 GPa. All three studies seek to improve our understanding of the geodynamic and geochemical consequences of melting beneath oceanic ridges and beneath island arcs, and will improve understanding of the effects of variable mantle composition on melting processes. The education portion of the plan involves development of a tutorial and laboratory exercises for an upper division course in petrology and using the petrologic phase equilibria program, MELTS. The exercises will constitute a two week unit of laboratories at UM and wil emphasize forward modeling and hypothesis testing as scientific tools as well as aid in a deeper understanding of petrologic topics discussed in lectures. Additionally, tutorials and resource-sharing will aid dissemination of these curricular developments to faculty teaching petrology at neighboring colleges and universities and to the geoscience community at large.