Professor, Earth & Space Sciences
Box Number: 351510
Astrobiology Areas of Interest: Origin & Evolution of Life on EarthC.V.: cv 2018.rtf_.doc
I am interested in the origin and earliest evolution of life on Earth and how that can be used as an analogue for life elsewhere in the Universe. My research techniques lie at the intersection of geology, biology and chemistry, examining the oldest and best-preserved rocks available. This involves fieldwork in the Australian outback, on the Greenland ice-cap, the South African veld and in the Canadian woods, amongst other places.
Examples of current projects include:
Early evolution of bacterial metabolism palaeontology and stable isotope geochemistry of Archaean sedimentary rocks, with the aim of determining when the main forms of microbial metabolism first arose and whether this caused environmental change in the atmosphere and oceans.
Early atmospheric composition and pressure - studying detrital heavy minerals in Archaean fluvial sandstones, raindrop imprints in ancient terrestrial sediments, and vesicle size in ancient basalt flows emplaced at sea-level, with the aim of determining whether the atmospheric greenhouse effect was modulated by carbon dioxide or some other gas in order to counteract the weaker solar luminosity during Earth's early history.
Secular trends in marine nutrient fluxes and their ecological impact - phosphorus and nitrogen geochemistry in sedimentary rocks through time, with the aim of better quantifying oceanic fluxes and budgets for these elements, identifying temporal trends in their sources and sinks, and determining whether these reflect or influenced ecosystem evolution.
Early evolution of continental crust - trace-element and radiogenic-isotope geochemistry of basalts ~3.5 billion years old across an ancient unconformity in the Pilbara Craton, Australia, with the aim of contraining the primordial growth rate of continental crust, the tectonic environments of the early Earth and the biological impacts of crustal differentiation.
Molecular fossils from early Precambrian rocks - organic geochemistry of well-preserved Archaean and Palaeoproterozoic hydrocarbons and kerogen, with the aim of discovering organic geochemical biomarkers that constrain the phylogenetic history of microbial ecosystems.