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Noble gas distributions in olivine

Noble gas isotopic ratios are one of the few tools we have to study the deep mantle. Finding these rare gases, however, can be difficult. I am developing techniques to better identify noble gas-bearing samples by scanning mineral grains (such as the one pictured here; ~ 3 mm in diameter) with X-ray computed tomography. The black inclusions are spinel.

Radiogenic heat production

Crustal processes at granulite facies conditions and hotter remain enigmatic because melting and deformation commonly obfuscate the geologic record. I combine geochronology and mineral geochemistry of accessory phases (zircon, monazite, rutile, etc.) to understand extreme heating events. My research in Madagascar indicates that the radioactive decay of thorium can be a major source of heat during collisional tectonic events.

Phosphorus fluxes to the ocean from igneous rocks

 The rate of phosphorus---a biolimiting nutrient on geologic time scales---delivery to the oceans is linked to tectonic processes. My research suggests that extensive flood basalts that erupted in the Neoproterozoic were a fertile source of phosphorus that could have increased primary productivity in the oceans and destabilized global climate.

Himalaya gneiss dome formation

Locallized extension in the upper crust allows partially-melted middle crust to upwell, forming Himalayan gneiss domes tens of kilometers across. My research on Gianbul gneiss dome in northern India sheds light the role of partial-melting in the Himalayan orogen.