Gray Bebout

Gray Bebout is a Professor in the Department of Earth and Environmental Sciences at Lehigh University, where he has been a faculty member since 1991 and recently served as Department Chair from 2019-2024. His academic journey includes a B.S. and M.A. in Geology from the University of Texas at Austin, a Ph.D. in Geology from UCLA (1989), and postdoctoral work at the Carnegie Institution of Washington (1989-1991).

Dr. Bebout's research focuses on volatile cycling in Earth's systems, particularly nitrogen and carbon cycling in subduction zones. His work spans field studies in the Italian/French Alps and New Zealand's Hikurangi margin, laboratory analyses of rock samples, and collaborative research on Mars analog materials with institutions in Japan. His research laboratory in Lehigh's STEPS building houses a gas-source isotope-ratio mass spectrometer for analyzing small amounts of CO₂, N₂, and O₂.

His research interests include Stable Isotope Geochemistry, Petrology, Solid Earth processes, Astrobiology, and the biogeochemical cycling of nitrogen. Current projects investigate slow, non-anthropogenic cycling of volatiles at subduction zones and the study of Mars analog materials, particularly analyzing altered volcanic glasses for nitrogen concentrations and isotope compositions.

Dr. Bebout teaches courses across the geology curriculum including mineralogy, petrology, and geochemistry at both undergraduate and graduate levels. His current teaching includes EES 131 (Introduction to Rocks and Minerals), EES 471 (Stable Isotope Chemistry), and specialized courses on critical minerals and the practice of science.

• 2018 Fellow, Mineralogical Society of America

As an advisor, Dr. Bebout supervises undergraduate and graduate research through EES 293 (Supervised Internship) and EES 393 (Supervised Research) programs. His research has been supported by field work in multiple international locations and collaborations with institutions in New Zealand, Japan, and Italy. He maintains an active laboratory program analyzing volatile elements in geological materials and has contributed significantly to understanding how volatiles cycle through Earth's crust and mantle.

Dr. Bebout's research group investigates the metamorphic pathways affecting volatile flux among Earth's major reservoirs (atmosphere, hydrosphere, biosphere, and lithosphere), with particular emphasis on nitrogen behavior as a tracer of biogeochemical cycling on Earth and potentially beyond.