In his research, Bebout considers the cycling of volatiles among the major Earth reservoirs (atmosphere, hydrosphere, biosphere, and lithosphere), with emphasis on understanding the metamorphic pathways affecting this flux. As one career-long research focus, he has explored the intriguing behavior of nitrogen and its utility in tracing modern and ancient biogeochemical cycling on Earth (and beyond). Bebout and his group currently investigate the (slow, non-anthropogenic) cycling of volatiles such as CO2 and N2 at Earth's subduction zones, with related research onging in the Italian/French Alps and on the North Island of New Zealand (the modern Hikurangi margin). The work on Hikurangi involves sampling of volcanic and cold-seep gases that are then analyzed at the GNS in Wellington, New Zealand, and at the University of Tokyo. Carbon, oxygen, and nitrogen isotope analyses of the rock samples collected in the Alps are conducted in Bebout’s laboratory at Lehigh University.
Another area of active research has been the study of “Mars analog” materials (available on Earth and known to be abundant on the modern Mars surface/near-surface), in particular analyzing altered volcanic glasses for their N concentrations and isotope compositions and the presence of key organic compounds. This astrobiology work is in part being conducted in collaboration with researchers at the Institute for Planetary Materials, Okayama University, located in Misasa, Japan. Bebout’s long-term affiliation with this institute began with a one-year sabbatical there in 2000.
Bebout's research laboratory is in the STEPS building, room 261 (across from the elevator in the C-wing), and at the center of this program is a gas-source isotope-ratio mass spectrometer capable of analyzing very small amounts of CO2, N2, and O2.