Collaborative Research: Using Melt Inclusions to Test Models for Wet Melting and Melt Extraction Beneath Mid-Ocean Ridges

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This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5).Mid-ocean ridges are the primary location of new crust generation. Because crustal creation impacts the structure of the crust and mantle in the region of generation, being able to read the geochemical clues of deep seated magmatic processes in surface-erupted lavas is critical to our knowledge of how the Earth works. This research uses state-of-the-art ion probe analyses of olivine hosted melt inclusions to examine magmatic processes that result in the chemistry of lavas erupted at mid-ocean ridges. It focuses on determining the concentrations of volatile phases, such as H2O and CO2, that are known to control mantle melting and impact eruption processes. Samples from the Southwest Indian Ridge and other slow and ultraslow spreading centers will be analyzed. The data which come from environments characterized by cooler thermal regimes; lower average degrees of melting; and extremely focused volcanism, will be compared with data from faster spreading ridges. Project outcomes include: (1) characterizing the relationship between H2O and degree of melting over a range of depths beneath mid-ocean ridge axes, (2) determining changes in melt chemistry along the ridges, and (3) quantifying volatile fluxes from ultra-slow mid-ocean ridge spreading environments. In addition the work helps us to better evaluate the extent to which olivine hosted melt inclusions record melting processes in other geologic settings. Broader impacts of the work include support for an early career scientist whose gender is under-represented in the sciences and undergraduate training. Results will also be made publicly available on the NSF-funded PetDB database.