Supplementary XRD Material for "Experimental Constraints on Barium Isotope Fractionation during Adsorption-Desorption Reactions: Implications for Weathering and Erosion Tracer Applications"

Repository Overview: Supplementary powder X-ray diffraction (XRD) data for the study "Experimental Constraints on Barium Isotope Fractionation during Adsorption-Desorption Reactions: Implications for Weathering and Erosion Tracer Applications" Data Provided: Powder X-ray diffractograms of the minerals used in the laboratory batch experiments. Pow Minerals Analysed: Clay Minerals: Kaolinite (KGa-2): purchased from the Clay Minerals Society (CMS). Montmorillonite (SWy-2): purchased from the Clay Minerals Society (CMS). Iron Oxyhydroxide Minerals: Goethite synthesised under alkaline conditions in the laboratories at the Department of Earth Sciences, University of Cambridge, following the method detailed in Schwertmann and Cornell (2008). 2-line ferriydrite synthesised in the laboratories at the Department of Earth Sciences, University of Cambridge, following the method detailed in Schwertmann and Cornell (2008) methods. XRD Methods: Instrument and Set Up: Theta-Theta D8 Bruker Advance diffractometer with a Mo anode, Lynxeye XE-T PSD detector and 2 mm divergent slit. Sample Preparation: Zero-background monocrystalline silicon plate was used to minimize sample mass. The X-ray diffractogram of the silicon plate was measured prior to each sample measurement. Clay Minerals: 0.02° step size and a 3s step rate. Iron Oxyhydroxide Minerals: 0.03° increments and a 1s step rate. Purpose of XRD Analyses: To verify the correct synthesis of iron oxyhydroxide phases and to detect impurities. To monitor any mineralogical changes that occurred during adsorption-desorption reactions with water. Data Format Column Name Description Unit twotheta 2θ ° intensity intensity counts per second (cps) ID mineral ID unitless mineral mineral name unitless duration reaction duration minutes Extra Notes A reaction duration of zero minutes corresponds to an unreacted mineral sample.