ACKNOWLEDGEMENTS
Farida Abubakari is the recipient of a UQ Graduate School Scholarship (UQGSS) from The University of Queensland. We thank Lachlan Casey (Centre for Microscopy and Microanalysis at the University of Queensland) for technical support with the µXRF analysis. The authors acknowledge the support of Microscopy Australia at the Centre for Microscopy and Microanalysis at the University of Queensland.