Research Opportunities at SIL
Subsurface Geochemistry: Graduate Student Position Available
Graduate student (MSc or PhD) sought for project on the origin, residence times and geochemical signatures of deep crustal fluids. Research on fracture fluids 1-3 km deep in Precambrian Shield rocks across Canada, Fennoscandian and South Africa has revealed that such fluids, like those at the hydrothermal vents, are rich in dissolved substrates such as hydrogen and methane (Sherwood Lollar et al., 2002 Nature; Sherwood Lollar et al., 2006 Chemical Geology). In 2006, in Science, Sherwood Lollar and colleagues in microbiology (Lin et al. 2006) demonstrated the role of such H2-rich fluids in sustaining chemolithotrophic microbial communities at 2.8 km below the surface in the deep gold mines of South Africa – one of the deepest microbial ecosystems yet discovered. Most recently, by incorporating conservative noble gas tracers, the extreme antiquity of these hydrogeologically ancient fracture waters has been demonstrated – with residence times ranging from tens of millions of years in the Witwatersrand basin (Lippmann-Pipke et al., 2011 Chemical Geology) to billions of years in the Timmins mine in Northern Ontario Canada (Holland et al., 2013 Nature).
Graduate students will contribute to research seeking to determine the extent and volume of this isolated hydrosphere; to determine the relationship of the free flowing fracture waters to trapped fluid inclusions; and to determine the habitability of this exotic realm of the deep subsurface and its implications for the search for extinct or extant life on Mars and elsewhere. Of particular interest to the MAGNET fellowship will be integration of CHONS stable isotope techniques at U of Toronto with novel developments in chromium isotopes at UBC that may allow determination of the provenance of fluids before and after oxygenation of the Precambrian atmosphere.
Applicants must have a BSc in a related field. Send a detailed CV and 3 letters of recommendation to:
Dr. B. Sherwood Lollar
Dept. of Earth Sciences,
University of Toronto
22 Russell Street
Toronto, Ontario
M5S 3B1 Canada
Tel: 416-978-0770
Geochemistry and Habitability of Ancient Waters: Postdoctoral Position Available
The Stable Isotope Laboratory, University of Toronto is part of the Deep Energy Directorate program of the Sloan Foundation Deep Carbon Observatory. An exciting opportunity exists for a postdoctoral fellow to join the University of Toronto team investigating the fluid and gas geochemistry, noble gas residence times and implications for subsurface habitability of ancient fracture waters in Precambrian Shield rocks. Working with an international team of geochemists (in collaboration in particular with C.J. Ballentine – Oxford) and microbiologists, the postdoctoral fellowship research will focus on understanding the distribution and residence times of ancient water in deep fractures; the relationship of fracture fluid geochemistry to the host rock and mineralizing fluids; and the water-rock reactions controlling the geochemistry and isotopic signatures of the waters. The research is part of a ten year interdisciplinary and international research program exploring the geochemistry and microbiology of deep Earth fluids and implications for Mars exploration and astrobiology.
Applicants must have a PhD in isotope geochemistry, geology, chemistry or related disciplines. Send a detailed CV, statement of research interest and 3 letters of recommendation to:
Dr. B. Sherwood Lollar
Dept. of Earth Sciences, University of Toronto
22 Russell St.
Toronto, Ontario, Canada
M5S 3B1
Tel: 416-978-0770
References:
1. Holland, G., Sherwood Lollar, B., Li, L., Lacrampe-Couloume, G., Slater, G.F. and Ballentine, C.J. (2013) Deep fracture fluids isolated in the crust since the Precambrian. Nature 497(7449): 367-360.
2. Lippmann-Pipke, J., Sherwood Lollar, B., Neidermann, S., Stroncik, N.A., Naumann, R., van Heerden, E. and Onstott, T.C. (2011) Neon identifies two billion year old fluid component in the Witwatersrand Basin. Chem GLG Vol. 283(3-4):287-296.
3. Lin, L.-H., Wang, P.-L., Rumble, D., Lippmann-Pipke, J., Boice, E., Pratt, L., Sherwood Lollar, B., Brodie, E. Hazen, T., Andersen, G., DeSantis, T., Moser, D.P., Kershaw, D. and Onstott, T.C. (2006) Long-term sustainability of a high energy, low diversity crustal biotome. Science 314:479-482.
4. Sherwood Lollar, B., Westgate, T., Ward, J., Slater, G.F., and Lacrampe-Couloume, G. (2002) Abiogenic formation of alkanes in the Earth’s crust as a minor source for global hydrocarbon reservoirs. Nature Vol. 416:522-524.