Research

Our researchers have developed innovative techniques to perform novel isotopic measurements (Craig et al., 2021; Lewis et al., 2022), modifications of models of planetary convection and crustal production and progress with first principles mineral physics calculations.

We have been able to characterise, to high precision, a homogeneous baseline Mg isotopic composition of Earth’s upper mantle against which any signature of magma ocean can be detected (Liu et al., 2023). We have also been able to quantify subtle changes in the Mg isotopic composition caused by melting and so the bias caused by using melts to access the composition of samples of the deepest mantle in upwelling plumes (Liu et al., 2022). 

We can now date potassium feldspar minerals in-situ using the Rb-Sr isotope system and can analyse Pb isotope composition of the same grains. We have made a proof of concept study in NW England and analysed grains form major modern rivers from India and China. We have also tested K-feldspar ages in the Archaean rock samples from the Pilbara craton in Western Australia. 

 We have extended calculations of Mg isotope fractionation between a magma ocean and the minerals that crystallise from it to appropriate great depths. We have also implemented new styles of crustal deformation and growth in our planetary convection model. These features have been used to reproduce modern observables on the surface of Venus (Tian et al., 2023), which helps calibrate behaviour for studying the early Earth.

Publications

Craig, G., Wehrs, H., Bevan, D.G., Pfeifer, M., Lewis, J., Coath, C.D., Elliott, T., Huang, C., Lloyd, N.S. and Schwieters, J.B. (2021) Project Vienna: A novel precell mass filter for Collision/Reaction Cell MC-ICPMS/MS. Analytical Chemistry 93, 10519-10527.

Lewis, J., Luu, T.-H., Coath, C.D., Wehrs, H., Schwieters, J.B. and Elliott, T. (2022) Collision course; high-precision mass-independent and mass-dependent calcium isotope measurements using the prototype collision cell MC-ICPMS/MS, Proteus. Chemical Geology 614, 121185.

Liu, X., Hin, R.C., Coath, C.D., van Soest, M., Melekhova, E. and Elliott, T. (2022) Equilibrium olivine-melt Mg isotopic fractionation explains high δ26Mg values in arc lavas. Geochemical Perspectives Letters 22, 42-47.

Liu, X.-N., Hin, R.C., Coath, C.D., Bizimis, M., Su, L., Ionov, D.A., Takazawa, E., Brooker, R. and Elliott, T. (2023) The magnesium isotopic composition of the mantle. Geochimica et Cosmochimica Acta 358, 12-26.

Tian, J., Tackley, P.J. and Lourenço, D.L. (2023) The tectonics and volcanism of Venus: New modes facilitated by realistic crustal rheology and intrusive magmatism. Icarus 399, 115539.