1. Environmental Change Research Centre, Department of Geography; University College London; London UK
2. NERC Isotope Geosciences Laboratory; British Geological Survey; Keyworth, Nottingham UK
3. School of Geography; University of Nottingham; Nottingham UK
4. Glasgow Molecular Organic Geochemical Laboratory, Department of Geographical and Earth Science; University of Glasgow; Glasgow UK
5. School of Geography, Politics, and Sociology; University of Newcastle upon Tyne; Newcastle upon Tyne UK
6. Organic Geochemistry Unit, Bristol Biogeochemistry Research Centre, School of Chemistry; University of Bristol; Bristol UK