Tracing battery metal (Li) mobility in pegmatite systems

The decarbonisation of the global economy is a pressing challenge in which Geoscience will play a key role. The transition to renewable power generation and storage will require a significant uptick in the sourcing of key metals over the next few decades, in particular lithium (Li), a key component of Li-ion batteries. A significant uptick in the sourcing of Li is predicted, hence a new and urgent focus in better understanding and exploring for Li-bearing deposits, which have hitherto been poorly studied.

Geologically, Li are principally found associated with the intrusion of silica-rich pegmatites. This deposits form endogranitic with the extraction of highly evolved magma, or by partial melting of Li- and Silica-rich sources (e.g., metasediments). Nonetheless the precise mechanisms of pegmatite evolution: (i) melt formation (ii) metal endowment, (iii) complex crystallization and specially (iv) the conditions that control economic mineralization, are poorly understood, hindering models of Li (and Li-Cs-Ta-Sn) deposit formation and development of new exploration tools.
This project will develop a dynamic research plan involving (i) field observations and sampling in at least one study area (Zimbabwe) with focus on the emplacement history of granite units using cross-cutting relationships and transects deep into the granite to build 3 dimensional views of the emplacement history and ore events; (ii) mineral geochemistry on mineral phases by laser ablation ICPMS to track crystallisation histories recorded by mineral growth within individual samples; and (iii) thermodynamic-geochemical modelling to constrain mineralization physico-chemical conditions. A range of other in-situ and whole-rock geochemical and isotopic approaches may be undertaken.
Analytical work will be carried out at the University of St Andrews and the British Geological Survey (BGS). The St Andrews Geochronology Laboratory (StAGE) and Isotope Geochemistry Laboratory (StAIG) are equipped with a variety of solution-based and laser ablation MC-ICPMS and QQQ-ICPMS facilities to undertake in-situ trace element and isotopic analyses of mineral phases. Additionally, the St Andrews School of Chemistry is equipped with an electron microprobe and SEM to perform in-situ analysis and electron-based imaging. The Geochronology and Tracers Facility at the BGS provides a wide range instrumentation available including a newly installed SELFRAG (high-voltage fragmentation system) instrument for mineral separation; laser ablation MC and SF -ICP-MS instruments, a low-Pb blank clean suite, and a state-of-the-art Isotopx TIMS for high- precision (CA)-ID-TIMS U-Pb geochronology.
The ultimate goal of the project is to characterize the mobility Li in the studied site(s), the role of source and whether ordinary crustal abundances of these metals are sufficient to generate economic deposits, the nature of metal mobility during magmatic evolution and vapour saturation, and the different petrogenesis between mineralized and barren pegmatites, to build widely applicable genetic models. The multi-disciplinary approach used in this project has the potential to transform our understanding of such systems and the results will be of wide interest to petrologists, economic geologists, and exploration companies. Better characterization of battery metal-bearing granitic-pegamatite systems will ultimately help in their exploration and extraction, helping ensure new supplies of this metal key to the decarbonisation of society.


Training will be taken in the following analytical techniques and software:

-LA ICP MS
-EPMA and SEM
-Geochemist Workbench
-SuperPHREEQC and PHREEQC
-ThermoCalc