[ESS] Juliet Ryan-Davis (MIT)

“Understanding critical mineral potential of primitive subduction zone magmas: A case study of the Moxie pluton, northern Maine, USA”

Nickel, plus associated cobalt, copper, ± platinum group elements, are metals that are critical to infrastructure for energy and global sustainability (i.e., batteries, turbines, and steel). Most known economical Ni-(Co, Cu, PGE)-sulfide deposits globally formed in plume or extensional tectonic settings and not subduction zone settings. My research focuses on subduction zone settings to understand whether they have been overlooked as potentially forming such deposits, or if they are fundamentally restricted based on their unique intrinsic magma compositions and properties. In particular, I focus on the upper-crustal mafic Moxie pluton in northern Maine, which hosts sulfide bodies, and compare this pluton to existing data from lower-crustal cumulate counterparts from Connecticut. I will discuss how interaction of mafic magmas with surrounding rocks governs the enrichment (or lack of enrichment) of sulfides to form these critical metal deposits.

About this week’s speaker:
Juliet Ryan-Davis is currently a Crosby Postdoctoral Fellow at Massachusetts Institute of Technology, and is starting as an Assistant Professor at Boston College this summer 2026. She is originally from the Boston area and has a BA in Geology from Middlebury College in Vermont. However, she spent over a decade enjoying the geology of California: prior to her MS and PhD at Caltech, she was a post baccalaureate researcher at Pomona College, served twice as an AmeriCorps member in the Sierra Nevada, California for the National Park Service and a non-profit, and worked for several years as a Geologist at the U.S. Geological Survey studying volcanoes in the western U.S. and around the world.

This talk was rescheduled from 4/7/2026.

Earth Science Seminar —

Lecture portion of the EAPS graduate-level class 12.571, covering current research in geophysics, geology, geochemistry, and geobiology. All members of the MIT community are welcome to join for presentations by guest speakers, held approximately every two weeks during the term.

Contact: earth-science-seminar-info@mit.edu