Dr. Megan Holycross

Primary Investigator

Assistant Professor, Earth and Atmospheric Sciences, Cornell University

About my research

Over the last several decades, significant improvements in the resolution of analytical instruments has revealed the trace element chemistry of the Earth’s crust and mantle is highly complex and heterogeneous at both large (km) and small (nm) scales. My research seeks to understand the kinetic and thermodynamic processes that cause these heterogeneities, mostly through laboratory experimentation. I utilize partitioning experiments to examine how changes in pressure, temperature, oxygen fugacity and compositional parameters redistribute trace elements in the solid Earth over the global scale. I run diffusion experiments to measure cation mobilities in silicate minerals and melts to calibrate “crystal clocks” and quantify how kinetic phenomena influence the distribution of trace elements in magmatic systems. Combining these two techniques, I can understand how rocks record the conditions (T, P, fO2) and frequencies (t) of the heating, alteration and exhumation events that have differentiated the solid Earth.

About me

I joined Cornell’s Department of Earth and Atmospheric Sciences in July 2020. Prior to joining Cornell, I was a National Science Foundation Postdoctoral Fellow with appointments at the Smithsonian Institution and Yale University.

You can view my CV here .

PhD students

Odalys Callejas

PhD Student in Geological Sciences at Cornell (started 2022)

Odalys is a Latina, first-generation, PhD student and Dean’s Scholar. She earned her B.S. in Geology from the University of California, Santa Barbara, where she investigated lower crustal xenoliths from the Siberian Craton to understand the formation and evolution of continents. At Cornell, Odalys is experimentally characterizing MgO diffusion in hydrous silicate melts to constrain temporal records for global magmatic systems. Outside of research, she enjoys dancing by the lake, cooking at home, and volunteering in her local community.

Brendan Garvey

PhD student in Geological Sciences at Cornell (started 2022)

Brendan is interested in using petrology and geochemistry to explore magma storage in a variety of systems. He recently finished his MS at Western Washington University investigating magma storage at Koma Kulshan (Mt. Baker) through mineral-melt thermobarometry and thermodynamic modelling. At Cornell Brendan is calibrating Li diffusion in feldspar to use as a crystal clock to time magmatic processes.

Francesca Riley

PhD Student in Geological Sciences at Cornell (started 2023)

Francesca is a PhD student and Center for Teaching Innovation Graduate Teaching Fellow. At Cornell, she is currently investigating the effect of pressure on Fe-species partitioning between garnet and silicate melt and the subsequent effect on arc magmas. In 2023, Francesca received her B.S. in Earth and Environmental Sciences with Highest Honors from the University of Michigan. Her undergraduate research focused on modeling core crystallization regimes in Mars using multi-anvil press experiments. In her free time, she enjoys outdoor activities, including hiking, camping, and tending to her garden.