Iterative energy self-calibration of Fe XANES spectra. Erratum

A correction is made to the paper by Jones et al. (2020). [J. Synchrotron Rad. (2020), 27, 207–211].

In the paper by Jones et al. (2020), the authors have noted that an incorrect value was published for the calibrated Fe³⁺/ΣFe for the rafted pumice sample from the 2012 Havre eruption. The correct value is 0.257 (0.010) and is included in the updated Table 2 below and updated in the inset in Fig. 3(c) (overleaf).

Table 2
Summary of uncalibrated and self-calibrated values for the data presented in Fig. 3, where the uncalibrated, self-calibrated and expected Fe³⁺/ΣFe ratios are presented together with the required energy change (ΔE)

	Fe^3+/ΣFe
Sample	Uncalibrated	Self-calibrated	Expected	ΔE (eV)
MORB VG3450	0.591 (0.018)	0.129 (0.004)	0.132	0.8
RGM-2	0.535 (0.037)†	0.231 (0.016)	0.262 (0.015)‡	0.3§
Havre pumice	0.452 (0.031)†	0.257 (0.010)	—	0.5§

†Manually offset to be within calibration range.
‡RGM-1 values.
§After manual offset.

Figure 3 Demonstration of iterative energy calibration correction. (a) A MORB glass spectra (Smithsonian Institute sample number VG 3450), as collected by Berry et al. (2018) (orange dot–dashed line), iteratively self-corrected (solid black line) to the basaltic glass standards. Also shown for reference are the spectra for the 0.011 and 0.775 Fe^3+/ΣFe ratio standards (black dotted lines). The Fe^3+/ΣFe ratio (inset) for Method A (solid orange lines) and B (dashed blue lines) as a function of iteration number shows convergence to a single Fe^3+/ΣFe ratio. Similar treatment is shown for the RGM-2 reference standard (b) and an experimental section of pumice from the 2012 Havre eruption (c), both iteratively self-corrected to the rhyolite glass standards (Cottrell et al., 2009). Also shown for reference are the spectra for the 0.238 and 0.806 Fe^3+/ΣFe ratio standards (black dotted lines). The vertical dashed lines in (a)–(c) refer to the two points E1 and E2 in each case.