The hillslope processes that shape the mountainous terrain of the Pacific Northwest have contributed significant changes to the region’s river systems. In September 2017, a large wildfire burned the mountainous terrain cradling Eagle Creek, a tributary to the Columbia River. Since the fire, Eagle Creek has begun the process of recovery. Previous post-fire research has found that the characteristics of hillslope processes are altered by wildfire but expected to return over time, however stream process responses are less understood. This study looks to quantify the changes and downstream impacts these processes have had on Eagle Creek following the fire.

Thesis Proposal:

Immediately south of Mount Hood, OR, the Twin Lakes fault cuts off several drainage channels, forming a series of basins. The fault's relatively sharp topographic expression suggests earthquakes have ruptured at its surface since the region’s last glacial retreat. The presence of basins imply multiple fault ruptures in recent geologic time, deeming it a potential seismic hazard. My thesis investigates sediment from two of the fault-dammed basins, Lower Twin and Frog Lakes. I aim to determine how recently and how frequently the Twin Lakes fault has ruptured since basin formation, filling a gap in the region’s seismic risk analysis.

Hypervelocity impacts are the most fundamental process in Geology. Throughout the “deep time” of solar system history impacts have played a role in the formation of planets, modification of the surfaces of planetary bodies, and terrestrial mass extinctions. The goal of this Master's thesis project is to reconstruct the impact conditions via a battery of novel electron backscatter diffraction (EBSD) methods and shock thermobarometry of a suite of similarly shocked L-chondrites.

What processes may have formed/controlled the fabrics in ureilites?

Ureilites is a type of meteorite which formed from the disruption of an asteroid. It consists of minerals such as olivine, pigeonite, troilite, and high-pressure carbon phases like graphite and diamond. These meteorites, which are linked to magmatic origins, show signs of shock impact deformation, with their minerals arranged in preferred patterns or orientations called fabrics. However, the mechanisms and processes behind the formation of these fabrics remains uncertain.

My dissertation is focused on using a combined chemical-crystallographic technique (using the EDS and EBSD detectors on the scanning electron microscope) to evaluate the petrogenesis and shock deformation histories of lithic clasts in lunar meteorites. My big picture research goals are to be able to disentangle effects of shock deformation in lunar samples in order to properly evaluate primary chemical signatures obtained during crystallization within the Moon. The three lithic clast lithologies I am investigating are: 1) dunites, 2) spinel-rich rocks, and 3) felsites (granites).

My doctoral work focuses on understanding the chemical evolution of mafic (basalt and basaltic andesite) lavas in the central Oregon High Cascades. My overarching tasks are to 1) describe the distribution of mafic lavas in the Oregon High Cascades, 2) determine why basaltic andesites in particular are so abundant in this part of the Cascades, and 3) examine how the chemistry of individual volcanic centers compare to those in close proximity. I am using a combination of bulk rock geochemistry, new geologic dates, petrography, and eventually isotopes to answer these outstanding questions. 

Titled "Orphan Basalts: Investigating the Petrogenesis of Unassigned Eastern Oregon Basalts," my thesis project is focused on detailing the origins of basalts mapped within the Telephone Butte, Calamity Butte and Craft Point quadrangles located along the boundary between the Harney Basin and the southern foothills of the Blue Mountains Province. Named for the localities in which basalt samples were collected, several basalt units are mapped in each quadrangle. Similarities in geochemical analyses of each basalt unit suggest that although these basalts have different unit names, they are in fact related and likely originated from the same source. 

My research is focused in the central to northern Oregon Cascade Range. In this part of the Cascade Range, erupted lavas are very compositionally restricted as compared to other arc segments. Although the central to northern Oregon Cascade Range does have several large, more andesitic stratovolcanoes, such as Mt. Hood, Mt. Jefferson, and the Middle and South Sister, volcanism is dominated by hundreds of smaller, basaltic volcanoes. Studies of the Cascade Range have acknowledged the prevalence of basaltic volcanism in this portion of the range, but many regional studies have focused on the andesitic centers, leaving most of the basaltic centers unstudied. 

Volcanic eruptions release carbon dioxide (CO2) into the atmosphere, which contributes to the carbon cycle. However, much is still unexplored about how volcanic eruptions affect the movement of organic carbon from vegetation and soil. My thesis focuses on the impact of the 1980 Mount St. Helens eruption on the terrestrial carbon cycle. It examines how the eruption affected carbon storage in vegetation and soils in the affected area. By comparing terrestrial carbon levels before and after the eruption, we aim to establish a carbon budget for the period since 1980. 

Temporal clustering of deep-seated landslides in the Puget Lowlands; a seismic trigger? 

The Puget Lowlands of Washington State is about the most seismically active region in the Pacific Northwest. Paleoseismic records show ample evidence of prehistoric crustal and Cascadia megathrust earthquakes in the region with a temporal cluster of earthquakes in the crustal faults about 1000 years ago. Although multiple paleoseismic records exist for crustal and Cascadia megathrust earthquakes in the area, little is known about the temporal and spatial distribution of earthquake-triggered landslides. To address this, we conducted a comprehensive study applying surface roughness age dating techniques to over 600 landslides in the lower Puget Sound region to explore earthquake-triggered landslides' spatial and temporal patterns. 

Black shales are rocks that are enriched in heavy metals and metalloids. Previous studies have shown that agriculture crops grown on soils formed on black shales pose a health hazard to humans and biota. However, no study has been conducted on the environmental hazard that these outcrops may pose in watersheds with black shale outcrops. I will be studying how these heavy metals are partitioned in streams once released during weathering; heightened knowledge is needed in this area so that state agencies may better protect human and environmental health in areas where metalliferous black shales occur. 

My master’s thesis focuses on understanding magma evolution and eruptive history of Three Fingered Jack, a dissected mafic composite cone volcano in the central High Cascades of Oregon. This region is characterized by intra-arc extension, creating an extensive mafic platform dominated by dozens of small scoria cones and voluminous mafic flows of basaltic and basaltic andesitic composition. It has the largest concentration of mafic monogenetic volcanoes in the entire Cascade arc, some of which have erupted in the past 2,500 years. Three Fingered Jack is much larger compared to its neighboring scoria cones.

My research is focused on understanding shock deformation in shergottites, the most commonly sampled Martian meteorites. My goals are to estimate deformation intensities in shergottites, identify the number of asteroid impact events they have undergone, and develop additional deformation estimation criteria based on changes in the crystal structure of key minerals such as olivine and pyroxene. Understanding the shock deformation in shergottites (and, by extension, all Martian meteorites) will allow for an unbiased interpretation of primary features that can reveal a lot about the geologic processes that shaped Mars.