Chris Holmden

Chris Holmden joined the Department of Geological Sciences at the University of Saskatchewan in 1996. In 2002, he founded the Saskatchewan Isotope Laboratory (SIL), which is housed in the Department of Geological Sciences. This was made possible with funding from the Canadian Foundation for Innovation. The funding enabled the building of a state-of-the-art trace metal clean room and the acquisition of modern mass spectrometers (IRMS, TIMS and MC-ICP-MS). With these improvements, SIL researchers enjoy access to nearly the entire periodic table for isotopic tracer applications in the earth sciences.

Along with his students and collaborators, Chris has made new tracer development an integral component of the research, which is broadly aimed at improving our understanding of the events and processes that have shaped the Earth since its origins, as well as the evolutionary history of life on Earth.

Current research utilizes:

• Cr and U isotopes to elucidate the oxygenation history of the Earth
• Ca isotopes to probe the meaning of the very large shifts in sedimentary inorganic and organic C isotopes preserved in marine sedimentary rocks through time
• Ca, Mg, and Sr isotope studies of dolomite aimed at understanding its complex origins in the sedimentary rock record
• Cr isotopes as tracers of the modern ocean Cr cycle (with Canadian GEOTRACES)

In addition, isotopes are used to study elemental cycling in modern environments, such as soils and forests, rivers and lakes, oceans and marginal marine environments, in order to comprehend the processes that fractionate isotopes. This introduces new isotopic tracer techniques to the biological, environmental, and marine sciences, while amassing the information needed for paleoproxy development and applications to earth sciences.