My main research interests are in astrobiology, geochemistry and geobiology. My PhD involved testing the capabilities of Raman spectroscopy for the analysis of Mars analogue rocks, in preparation for the ESA 2020 ExoMars mission. I also researched the effect oxidative weathering has on the Raman spectra of carbonaceous rocks. As organic carbon is one of the building blocks of life it is one of the main goals of the missions, and if found on Mars, it is likely it will have been oxidised.
Sulphate deposits are regarded as important sites on Mars to search for signs of life. I determined whether Raman spectroscopy can distinguish between Ca-sulphates with varying degrees of habitability, based on analogues from the Haughton impact crater.
A major part of my research was analysing the geochemistry of reduction spheroids using scanning electron microscopy (SEM). I analysed and recorded the occurrences of selenium (Se) and tellurium (Te) and other elements such as U, V, Mo, Cu, Pb and REE’s. Reduction spheroids, commonly associated with sandstone-hosted uranium deposits can be used as indicators for regional metal anomaly’s, which could be large enough to extract, and cause a potential contamination risk. I contributed to work which assessed the abundances of selenium in Carboniferous shales, which could be seen as an opportunity or a potential contaminant for shale gas extraction.
I am interested in the interaction between geology and biology. Reduction spheroids, found in continental red beds are largely considered a microbial feature. Certain strains of iron reducing bacteria have the ability to swap out Fe oxides for selenium as the electron acceptor, resulting in an enrichment in Se within reduction spheroids. As selenides are more common than sulphides in reduction spheroids, this suggests that sulphate reducing bacteria are being out-competed by iron reducing bacteria. I cultured iron reducing bacteria in a synthetic iron-rich sediment to ultimately prove their microbial origin. I therefore have experience in anaerobic microbiology including the aseptic techniques required to successfully sustain growth.