Table 3.

Manganese XANES Linear Combination Fitting (LCF) Results^a

	proportion of LCF fit
	MnIISO4(aq)	β- MnIIIOOH	(Fe,MnIII) SiO3	AOS	χ 2
Mn	0.06	0.76	0.19	2.94	3.2x10−4
Mn + HCO3	b.d.b	0.95	b.d.	2.96	7.3x10−5
Mn + As	0.39	0.32	0.29	2.62	2.8x10−4
Mn + As +HCO3	0.20	0.62	0.19	2.80	1.2x10−4

^aAverage oxidation state (AOS) was calculated using the relative proportion of each standard, but the reference standards used should only be interpreted in terms of Mn oxidation state in this analysis.³⁸

^bbelow detection (<0.05).