Environmental geochemistry: element cycling through Earth's surface systems
The BRG use several isotopic and elemental tools to study Earth surface process at the intersection of the hydrosphere-atmosphere-lithosphere systems. Emphasis is on understanding the surface cycling of ultra-trace elements (e.g., W, Mo, Tl, REE+Y) present at sub-microgram/gram levels through soils, sediment, and river waters. The new and often still emerging utility of ultra-trace elements in environmental systems is an essential extension from more traditional tracers (e.g., major ion abundances in waters), allowing for clearer connections to be drawn between our surface environment, geology, hydrology, and people. Many ultra-trace elements are also on Canada's "critical minerals" list; understanding how these elements are distributed from source to sink through surface environments helps with (1) exploring for new ore deposits, (2) tracing anthropogenic contamination sources/mobility processes, (3) developing environmental baselines for elements with currently poor constraints, and (4) establishing novel provenance links between biogeochemical samples and specific environments. Studies of surface environments are also essential to making refined predictions of how they will evolve into the future with a changing climate, and also to calibrating the geochemical signatures observed in similar depositional environments of the sedimentary rock record.