Riley Rohrer

I completed my undergraduate degree at University of California, Santa Barbara (UCSB) in 2019. My senior year I completed a senior thesis titled “Using multiple geochronometers to better constrain the tectonic events in Central Nepal.” We used zircon, monazite, apatite and allanite to date multiple geologic processes and better construct the timeline of original igneous intrusion to metamorphic deformations. After graduating, I continued working in the labs at UCSB and on projects for Professor John Cottle and was later picked up by Professor Francis Macdonald. I’ve worked on a large variety of old zircons (Slave Craton zircons) and young zircons (Monterey Formation ash units) and how to sample and date the correct representation. I have also helped develop mineral separation techniques and many undergraduate and graduate students in the art of mineral separation at UCSB.  

My PhD work is in the Fraser Zone, part of the Albany-Fraser Orogen in Western Australia, looking at the metamorphic history of the region. Previous studies have been limited to outcrop (which is few and far between), but by joining forces with industry partners we have new access to rocks buried beneath regolith in hopes to better understand the tectono-thermal evolution of the Fraser Range. I use a mixture of methods to give better insight to complex geologic histories such as multiple geochronometers to date different events, geochemical analyses of garnets to track changes in melt systems, and thermodynamic modelling. When combined, we have the best chance at unlocking the metamorphic conditions and history.