Identifying past life and habitable environments on Mars

My research will approach the question of life on Mars from two angles: the first is to examine Precambrian fluvial and lacustrine sediments on Earth that are analogous to Martian aqueous sedimentary rocks - this will help us to understand how habitable environments may be recorded in the Martian rock record; the second is to look for these and similar signs on Mars' surface to construct a picture of the spatial and temporal evolution of Mars' environmental conditions in its early (c. 4 billion years ago) history. The methods I will use in these two approaches will be aimed at sedimentary and stratigraphic analysis of the rock record; on Earth this will involve field study and optical microscopy, on Mars I will use digital terrain models with overlain orbital spectral imagery. I will also use Raman laser spectroscopy to help understand how microbial fossils are preserved in these ancient terrestrial sediments, and thus how we might search for them during rover missions on Mars.