Geochemical evolution of the Earth's surface
We pursue diverse and dynamic research programs that are linked by a single broad objective – to understand the evolution of the Earth’s surface through Earth history. A major component of our research involves the use of established and novel geochemical and isotopic tracers to investigate and characterize modern global oceanic biogeochemical cycles, to better understand material fluxes at the surface of the Earth, and in particular their impact on the chemistry and biology of the ocean. We apply the understanding to the past Earth, using sediments and rocks that record past ocean chemistry and biology, to document perturbations in these geochemical cycles though time and their inter-relationship with Earth’s climate, environment and biosphere.
The group’s research interests follow three main themes.
Earth's biogeochemical cycles, past and present
One of our principal research goals is to understand the global cycling of trace elements, how these cycles link to those of carbon and water, and how they are reflected in, and influence, Earth’s biosphere. Our ultimate aim is to use the trace element chemistry and isotope geochemistry of the oceans and their sediments to learn about the past environment of the Earth, including its evolving biosphere.
Rivers, chemical weathering and erosion
Large rivers carry the products of physical and chemical weathering of the continents to the oceans. As such they are a major influence on ocean chemistry, both now and in the past. The spatial and temporal pattern of chemical weathering is also an important part of the long-term (geological) carbon cycle, the driver of icehouse/greenhouse worlds on Earth, and the climate of the planet generally. We seek to use the chemistry and isotope geochemistry of large rivers and their sediments to understand these major processes.
Sediments and rocks formed in the ocean represent our most important archives of information on the Earth’s past environment. A third theme focuses specifically on ocean chemistry. We survey patterns of chemical and isotopic variation in the modern oceans (e.g. as part of the international GEOTRACES programme). We try to understand these through modeling. And we use laboratory microcosm experiments to characterize and understand the biological and abiotic controls on specific chemical signatures seen in the real oceans.