Environmental mineralogy

Minerals at Earth’s surface form during dynamic interactions between gases, water and living organisms. Because of this, minerals can be used as a record of transient states of the atmosphere, hydrosphere and biosphere throughout our planet’s history. They are also sources of essential elemental nutrients needed for life and they serve as safe stores that lock away toxic elements. Chemical sediments, whether they form naturally in lakes or as a consequence of human activities, are some of the best places to study how crystals form and how they control Earth’s element cycles.

Lakes that sequester CO₂. Some lakes naturally remove CO₂ from the Earth’s atmosphere, storing it permanently within carbonate sediments that precipitate from lake water. These lakes can be incredibly biologically productive and sometimes have exotic solution chemistry. We are studying the biogeochemical conditions needed to form carbonate sediments and the mechanisms by which carbonate minerals form in lakes.

Our current work focuses on:

• Field work and laboratory studies of carbonate lakes in British Columbia and Saskatchewan, Canada and South Australia and Victoria, Australia.

mineral phase transitions. The first minerals to form from a solution are typically not the most stable ones. Instead, the minerals that are quickest and easiest to form will precipitate and then decompose in series to reach increasingly more stable compositions and structures. Mineral phase transitions release or sequester metals, acids, bases and gases. Because they are strongly dependent on environmental conditions, mineral phase transitions record information about past environments and they can be tailored to manage environmental health and for green industrial applications.

Our current work focuses on:

• Exploring the amorphous-to-crystalline transition in low-temperature minerals.
• Understanding what order–disorder in the structures of low-temperature minerals can tell us about their formation pathways.
• Determining how the chemical composition (also called ‘stoichiometry’) of minerals affects their decomposition products in natural and anthropogenic sediments.