PhD project in the University of Aberdeen

Identification of methane-rich rocks and their potential to
support life, on Earth and Mars

Supervisors: Prof John Parnell (Dept. of Geology & Petroleum Geology, University of Aberdeen) & Dr. Gail Ferguson (Microbiology Program, School of Medicine & Dentistry, University of Aberdeen)

One of the most interesting issues on Mars is the origin of the methane in the atmosphere. The methane may have relevance to the possibility of life on Mars, either as a product of microbial activity or as a potential fuel for microbes. Understanding martian methane is a major objective of the next European Mars mission in 2016. Eventually it will be desirable to sample the methane in concentrated form at the surface. However there are no data sets from ancient rocks to show their potential to retain methane, but an understanding of where methane becomes encapsulated in rocks and minerals is required before any surface sampling on Mars. We also have almost no data on long-term potential for methane-rich rocks to support extremophile microbial life. If microbial life does exist on Mars, it is likely to be deep subsurface and may be adapted to grow optimally under extremes of pressure.

This interdisciplinary PhD will investigate terrestrial analogues for rock types relevant to Mars (serpentinites, basalts, hydrothermal deposits), for methane distribution and retention/release. This will involve assessment of residence time in rocks, how the signature is affected by weathering/alteration, and how the signature varies between different minerals in a single rock. Methane generation on Earth today occurs particularly in deep ocean/sub-ocean floor settings, in serpentinites, pillow lavas and hydrothermal systems, where extremophile microbial populations use abiogenic methane (methanotrophs), or use hydrogen and generate methane (methanogens). Selected samples, particularly from the deep subsurface/ocean (serpentinites, pillow lavas) will be used in experiments to test their capacity to support microbial life.

Thus the PhD will provide a data base of methane anomalies in a range of relevant rock types, guidance on priorities for sampling and sample handling, and experimental results on what minerals/rocks can support microbial life and the nature of the microbes present.

The student will work within active research groups exploring aspects of geochemistry/planetary geology and microbiology, and receive training in microscopic, geochemical and molecular techniques.

Enquiries to Prof. John Parnell (j.parnell@abdn.ac.uk) or Dr. Gail Ferguson (g.ferguson@abdn.ac.uk).

Applications to be submitted by March 31 to Prof. Parnell in the first instance, including a c.v. with the names of two academic referees.