Position title: Professor
179 Weeks Hall
1215 Dayton Street
The most significant deformation of the earth’s crust is accomplished by major fault systems that extend into shear zones at depth. The central focus of my research is to understand how such brittle-to-ductile systems evolve in both space and time. This requires consideration of the mechanical behavior of earth materials at a range of depths, from granular porous media at the surface to crystalline rocks in the lower crust. I am particularly interested in:
- The mechanics of faulting and earthquakes, and quantification of recurrence intervals in deep time
- Strain localization at different crustal levels
- Strain partitioning over space and time within major crustal shear systems
- Constraining the timing and time-temperature history of deformation in fault and shear zones
- Fluid / fault interactions
- Petrophysical controls on deformation mechanisms and the link between permeability, diffusivity, and deformation processes
- Petrophysical controls on velocity and material properties of granular porous media
- Fabric development and deformation mechanisms in brittle and ductile shear systems
In general, I link observations made at different scales in order to solve specific problems. My work is rooted in detailed mapping and structural analysis, which forms the foundation for a range of laboratory analyses. Members of my research group and I routinely conduct microstructural and petrologic analyses using light and electron beam microscopy to investigate deformation mechanisms, alteration/metamorphism, and relative timing of deformation events. We are fans of isotopes, using radioisotopic analyses to constrain both the timing of deformation events and time-temperature histories of terranes of interest. Stable isotope analyses allow us to evaluate fluid sources and better understand fluid-rock interaction. We also use a range of tools to quantify material properties that control the hydro-mechanical behavior of rocks and sediments.
I am looking for students interested in a range of topics, including:
- Partitioning of extension in space and time within the belt of metamorphic core complexes exposed in Arizona
- Determining if fluids from the Valles Caldera drove faulting in the adjacent Rio Grande rift in New Mexico
- Quantifying the rock record of rheology in shear zones in the Sierra Nevada and/or Mt. Isa, Australia
- Linking the rock record of deformation at different crustal levels in California, Arizona, and New Mexico to better understand the Laramide orogeny
- Exploring an unusual record of the 1.4 Ga Picuris – Wolf River – Pinwarian orogenic event: Breccias in Baraboo Interval quartzites
The Structural Geology & Tectonics research group is led by Professors Basil Tikoff, Chloe Bonamici, and I and includes several graduate students and post-doctoral researchers. Learn more at the research group’s website.
The SG&T research group’s facilities encompass all scales of analysis and reflect our collaboration with other research groups in the Department of Geoscience.
GEOSCI 204: Geologic Evolution of Earth (Spring 2022)