The fate of sulfides during subduction
The bulk of my research focuses on the fate of sulfur in the subducted lithosphere. Sulfur is one of the six most abundant elements in the Earth, exhibits a wide range of oxidation states (-II to +VI). Sulfur in slab fluids and melts may drive oxidation of the upper mantle and arc volcanoes. Additionally, the breakdown of sulfides during subduction metamorphism may release economically important metals, such as copper. I employ a variety of field based, experimental, geochemical, thermodynamic, and isotopic techniques to investigate the redox reactions governing sulfur mobilization during subduction. |
Pushing the boundaries of in situ petrochronology
I employ a number of in situ petrochronologic techniques to investigate metamorphic and metasomatic processes. These include more traditional techniques, such as U-Pb(-Th) dating of phases, such as zircon, titanite, rutile, monazite, allanite, and apatite, as well as dating low U (<0.1 μg/g) phases such as garnet. The goal is to more precisely and accurately date metamorphic processes by discovering new ways to link time with changes in pressure, temperature, and composition. |
Measuring ferric iron in metamorphic minerals
Iron is the most abundant multi-valent element in many silicate rocks; however, precisely and accurately measuring the ferric/ferrous ratio in most minerals by traditional microbeam techniques, such as electron probe microanalysis, is not currently possible. I am working to develop new spectroscopic techniques for easily and rapidly determining mineral ferric/ferrous ratios. |