This research investigates the biogeochemistry of both ancient and modern systems utilizing a number of geochemical, biological and sedimentological techniques. Using molecular lipid biomarkers, inorganic geochemical proxies (such as reactive Fe speciation, Mo and other redox sensitive transition metal contents) and stable isotopes ( 13C, 15N, 34S, 18O) to record major episodes of environmental and biotic change through Earth history. One particular focus is the progressive oxygenation of the biosphere in the Proterozoic leading to the first appearance of animals. Co-evolution of aquatic environments and microbial community structure (bacteria, archaea and eukaryotes) over geological time. Understanding microbial, chemical and thermal processing (diagenesis and catagenesis) of sedimentary organic matter leading to petroleum, coal and natural gas generation. Development of analytical strategies for facilitating oil-source correlations in petroleum exploration and understanding basin charging of petroleum fluids.<br>Discriminating abiogenic (Fischer Tropsch synthesis in hydrothermal settings, meteorite input) from biogenic organic matter inputs preserved in the Archean rock record using molecular and compound-specific isotopes; C isotope patterns.<br>Investigating organic synthesis and preservation in the interstellar medium and on other planetary bodies (such as the icy moons, Europa and Enceladus) and developing the astrobiological search for chemical biosignatures.