Image: Anna and Jay with the Bruker D8 ADVANCE X-ray Powder Diffractometer at the University of Georgia Geology lab, May 1, 2017. Photo: Paul Schroeder. [Click image to enlarge]
Anna Wade (visiting from Duke University) and Jay Austin (based at the University of Georgia) are collaborating by using X-ray Diffraction (XRD) to determine clay minerals in the fine fraction and relative abundances of minerals in bulk samples. Identifying and quantifying phases in the Critical Zone is a challenge. Here they are setting up an XRD experiment in the UGA Geology lab. Methodologies for sample preparation, data collection, and subsequent quantitative model simulations are key for good precision and accuracy. Models being used in the process include NEWMOD for simulating mixed-layer clays structures and the Rietveld refinement method for quantifying model abundances.