Minerals are our best source of information on the conditions and compositions in the interior of the Earth and on its surface, both at the present time and back to its earliest history. The research conducted by my group aims to develop the tools necessary to extract this information from minerals. We use a combination of experiments and modelling to investigate how minerals take up elements from a fluid or melt, and how this composition depends on the pressure-temperature conditions during growth and the composition of the host medium. We then apply this understanding to natural samples to reconstruct the conditions and environment in which they formed.

Our present research focuses on determining the composition of aqueous fluids. Fluids have a major impact on the processes operating in and on the Earth, from enabling plate tectonics, to facilitating melting and volcanism, to segregating metals into ore deposits. Furthermore, life originated in an aqueous environment, and changes in its composition over time may well have guided life’s evolution. To understand these processes requires knowledge of the fluids involved, but, unfortunately, fluid samples, especially for deep in the Earth and far back in time, are rare.

Minerals provide an attractive alternative, because we have minerals with well-preserved compositions going back at least 4 billion years and to depths of several hundred kilometres. When growing in the presence of a fluid, minerals capture a compositional signature of this fluid, and if we apply appropriate element partition coefficients we can reconstruct the composition of the fluid from that of a mineral. Partition coefficients can be obtained in experiments, and the FlexPet Lab hosts a range of equipment that allows for experiments from surface conditions to 1800oC and 3 GPa.

Current research aims and interests

1. •develop a predictive model for mineral-fluid element partitioning
   

2. •understand the mechanisms of element uptake into mineral lattices
   

3. •predict partitioning systematics ab-initio using DFT atomistic simulations
   

4. •explore links between changes in ocean water composition and life’s evolution
   

5. •determine the composition of fluids released in subduction zones and involved in Mid-Ocean Ridge interaction to constrain element cycling through the Earth
   

6. •develop tourmaline as an indicator of P-T conditions and fluid composition
   

7. •determine thermodynamic data and solution models for the borosilicates,
   

    including tourmaline