When did oxygen appear in Earth's atmosphere? Was the early Earth's climate warmer or cooler than today? How deep in the crust does the biosphere extend? What are the main sources of atmospheric methane? My research group uses stable isotopes as a tool to answer these questions. We study minerals formed billions of years ago or deep in the oceanic crust, as well as trace gasses from the atmosphere, cow rumens, and from the deep subsurface. We apply state-of-the-art technology to unlock the isotopic signals for microbial, hydrothermal, and photochemical processes. In order to interpret the information contained in these signals, we utilize theory and laboratory experiments to develop and refine the isotopic proxies for specific biochemical, atmospheric and geological processes.
Our current research projects include:
1) methane clumped isotopologue, 13CH3D, as a new tracer for the source of geological, microbial, and atmospheric methane. We use it to trace deep methane cycles for sites of serpentinization, deep sediments, thermogenic gas, and methane hydrates. We are also working on culture experiments.
2) sulfur isotope (32S/33S/34S/36S) effects during photochemistry and microbial processes to bring new insights into redox balance in deep time and deep biosphere. In particular, theoretical and experimetnal studies to test the origin(s) of sulfur isotope mass-independnet isotope fractionation.
Please click through the menu links above to learn more about what we do, and check out our recent news and publications to the right. Interested students are encouraged to inquire about potential research projects in the laboratory!