Mylonitic, migmatitic Hauser Lake gneiss, Priest River complex, ID
Metamorphic Geology
I am a metamorphic petrologist - a geoscientist who studies the origin of metamorphic rocks. Even more broadly, I consider myself a metamorphic geologist because I use the skills and tools of a field geologist, petrographer, traditional petrologist, structural geologist, geochemist, geochronologist, and numerical modeler to tackle my research. These many skills and approaches are necessary when you consider that many metamorphic rocks experience not just metamorphism, but deformation, partial melting (anatexis), and exhumation. When we are able to decipher all of the events and processes recorded by metamorphic rocks, we gain a more complete understanding of Earth's materials, features, processes, and history. Current and recent research includes work in the Llano uplift of Texas and in the Priest River metamorphic core complex of northern Idaho.
Are you interested in "hard rock" research, such as metamorphic petrology, igneous petrology, structural geology, geochemistry, geochronology, and related topics? If you're a prospective graduate student or an SFA undergrad interested in getting some research experience, check out my students' research and then get in touch!
The Llano uplift, central Texas
My current research focuses on the Mesoproterozoic metamorphic and igneous rocks exposed within the Llano uplift. My goal with this work is to refine the metamorphic history of the Packsaddle and Valley Spring domains. Part of this work includes developing a more detailed understanding of the intrusive relationship between these rocks and the younger Town Mountain Granite. This work can help us to better understand the southern extension of the Grenville orogen. The methods employed here include detailed field studies, petrography, bulk rock geochemistry, thermodynamic modeling, and geochronology.
Priest River complex, northern Idaho
How do metamorphic core complexes (MCCs), geologic structures that form through extension, develop in fundamentally compressional tectonic settings, such as the northern Rocky Mountains? MCCs exhume metamorphic rocks from Earth's middle or lower crust. These metamorphosed and deformed rocks record both the conditions of metamorphism at depth and the circumstances of their own exhumation. By studying these rocks, we can learn more about the development of the MCC itself. The Priest River complex, located in the northern Idaho panhandle, typifies the MCCs of the northern Rocky Mountains. Through a variety of methods, a detailed pressure-temperature-time (P-T-t) history of the Priest River complex, including metamorphism, deformation, crustal melting, magmatism, and exhumation, was developed to better understand the development of MCCs in this region. See Stevens et al. (2015, 2016, 2017) for more information.
Approaches to Research
I have employed a variety of methods (below, italicized) to approach a variety of research goals (gray boxes). These methods include field work, thin section petrography, mineral and rock chemistry, thermodynamic modeling using THERMOCALC, monazite U/Th-Pb and REE petrochronology, zircon U-Pb geochronology and Hf isotopes, and interpretation of numerical modeling.
