Sandy Schwarzbart, MS candidate

My thesis examines faulting within the Mount Hood National Forest. Previous work mapped the Quaternary active Clackamas River Fault Zone (CRFZ) and the Holocene active Mount Hood Fault Zone (MHFZ). Lidar data collected in 2021 revealed previously unmapped lineaments between them. My study assesses the activity of these faults and their relationship to the proximal fault zones. Using lidar and a paleoseismic trench, we suggest these faults make up a Holocene active section of the CRFZ and may provide a kinematic link with the MHFZ.

I have completed mapping the faults within this zone as well as their overlap with the previously mapped CRFZ, including calculating the displacements of the faults at over 200 locations across the study area. I have also completed the trench investigation which included the collection of datable organic material which I used for radiocarbon dating to determine the Holocene activity of one of the faults within the study area. I am still waiting on laboratory results such as IRSL dating of multiple stratigraphic units and Ar/Ar dating of a tuff unit that made up most of the footwall that we exposed in the trench. I am also working to calculate slip rates and ages of the scarps based on the surface curvature and scarp diffusion calculations.

My projected date to defend my thesis is May or June of 2026.