Supplemental Material: Alteration, mass analysis, and magmatic compositions of the Sentinel Bluffs Member, Columbia River flood basalt province

Geosphere, February 2018, v. 14, p. 286-303, doi:10.1130/GES01188.1, Supplemental File 3. Documents sampling procedures, and the precision and accuracy of XRF analyses of Sentinel Bluffs Member (SB) samples performed for this study. Discusses differences between these and earlier (pre-2004) analyses of Sentinel Bluffs Member (SB) samples. Presents a method for estimating analytical precision, and precision estimates for SB compositions. Describes the supporting documentation provided with analyses in Supplemental File 2. Explains the use of the MI100 calculation spreadsheet provided as Supplemental File 4.