I investigate a broad variety of tectonic problems using petrology, geochemistry, and geochronology, in concert with geologic mapping. Many of my research advisees learn to use our department's X-ray fluorescence spectrometer, rock fabrication and mineral separation equipment, and GIS or petrological modeling software. Scroll down for more.
Crystalline basement in this region is dominated by 90-82 Ma high-flux arc magmatism, broadly similar to coeval magmatism along the crest of the Sierra and along the length of Baja California (figure at left). A second, enigmatic pulse of magmatism followed at ~77 Ma, a time at which magmatism is not usualy found this far west in the Cordilleran arc. Primary magmatic structures in the western Mojave have since been rearranged by at least 4 later structural developments:
1. Late Cretaceous top-to-the-SW compressional fabrics and faults
2. Later Cretaceous extensioanl fabrics and faults associated with retrograde metamorphic assemblages, mylonization, and cataclasis
3. Oligo-Miocene extension, alondg both high-angle and apparently low-angle normal faults
4. Miocene to present transrotation, largely actuated by NW-striking, still-active right-lateral strike slip faults
To begin reconstructing this rather complicated puzzle, my students and I are working on a variety of projects in the area, including geologic mapping (both in the field and using remotely-sensed data), geochemical, petrographic and petrologic analysis, and geochronology/thermochronology (in collaboration with CSUN and Stanford University).
I have also advised students on a broad variety of other projects, ranging from the geologic mapping of metamorphic sequences, to measuring the structures related to near-surface folding of solid granite, to analyzing the metasomatism of economic marble deposits, to mapping Quaternary landforms via GIS, to rock-glacier dynamics and geochemistry of archaeological samples.
Blachly, G., 2021, The Ludlow batholith, central Mojave Desert, California: Late Cretaceous magmatism synchronous with destructive Laramide events.
Strom, C., 2019, Correlation between headwall steepness and rock glacier size on Earth and Mars.
Zylstra, S., 2017, Late Cretaceous plutonic and metamorphic overprint of Proterozoic metasediments of Ontario Ridge, eastern San Gabriel Mountains, California
Rucker, B., 2022, An assessment of the Red Cloud Mine
Renner, A., 2021, Geologic examination of part of the northern Soda Mounatins, CA
Ruiz, J., 2021, Petrographic description and structural interpretation of the eastern Soda Mountains
Peña, V., 2020, Geochemical mapping of the southern part of the Jackrabbit Hill Quadrangle
Davis, M., 2019, A Study of the Birch Creek Pluton, White Mountains, California
Zúñiga, J.A., 2019, Chemical Analysis of Unknown Mineral Specimens Using X-Ray Fluorescence
LeBeau, A., 2018, Reinterpretation of Faulting and Folding in the Big Maria Mountains, Riverside County, California
Prizlow, A., 2018, Geochemical analysis of Cretaceous plutonic rocks from the northwestern Mojave Desert batholith
Valenciano, J., Reconnaissance geochemical analysis of the southern Sierra Nevada
Wieland, A., 2018, Geology of the Adobe Mountain Quadrangle, Western Mojave Desert, California
Dossey, M., 2017, Transpression overprinted by extension forms a structural dome in brittle granite, southwestern Soda Mountains, Mojave Desert, California
Mayfield, K., 2017, Contact metamorphism and metasomatism at CalPortland Mojave Quarry, Kern County, California
Brigham, K., 2016, Geochemical analysis of Late Cretaceous intrusive rocks in the western Mojave Desert, California
De Leon, A., 2016, Geologic Mapping of the northern Calico Mountains, Mojave Desert, California
Robles, T., 2015, Spring Discharge and Mineral Deposits near Robert’s Mine Exploratory Tunnel in the San Gabriel Mountains