CHEM 1223A

bharms [at] umd [dot] edu

James Farquhar

ResearchGate

I am broadly interested in how stable isotopes can be used to investigate atmospheric evolution, climate change, and biogeochemistry. The focus of my PhD dissertation is the measurement of the four stable isotopes of sulfur (³²S, ³³S, ³⁴S, ³⁶S) as a proxy for the following: 1) metabolic changes in sulfate/sulfur reducing microbes in response to environmental stressors, 2) the origin of secular changes in atmospheric chemistry during the Archean Eon (2.5 – 3.8 Ga), and 3) the emergence and/or extent of various sulfur metabolizing lifeforms over geologic time. I am also interested in the fundamental causes of exotic isotope effects, as predicted by quantum mechanical principles. My field areas are primarily in Greenland and arctic Canada. I hope to expand my work to rocks in South Africa and Western Australia.

Oduro, H., Harms, B., Sintim, H. O., Kaufman, A. J., Cody, G., Farquhar, J.. (2011) Evidence of magnetic isotope effects during thermochemical sulfate reduction. Proceedings of the National Academy of Sciences. 108 17635-17638. DOI: 10.1073/pnas.1108112108

Farquhar, J., Cliff, J., Zerkle, A.L., Kamyshny, A., Poulton, S.W., Claire, M., Adams, D., and Harms, B.. (2013) Pathways for Neoarchean pyrite formation constrained by mass-independent sulfur isotopes. Proceedings of the National Academy of Sciences, USA.