Application of advanced x-ray spectroscopy techniques to the quantification of Fe speciation in basaltic silicate glasses

Here, we propose to investigate the application of advanced x-ray spectroscopy techniques to the quantification of Fe speciation in basaltic silicate glasses--the primary method by which the oxidation state of magmas is determined from natural glasses. We will collect Fe K-edge Kβ mainline HERFD and Kβ1,3 XES of the Berry et al. (2018) suite of synthetic basaltic glasses previously characterised by conventional PFY XANES and Mössbauer spectroscopy. Via the HERFD dataset we can evaluate the increase in sensitivity, and reduced influence of main edge background on the pre-edge feature employed for Fe species quantification. This may reveal Kβ mainline HERFD as a superior method permitting direct comparison between datasets due to reduced sensitivity to background subtraction. The XES dataset will permit assessment of the technique as an alternative method with potential application employing laboratory-based instruments.