X-ray Amorphous and Poorly Crystalline Fe-Containing Phases in Terrestrial Field Environments and Implications for Materials Detected on Mars

Recent analyses of X-ray diffraction (XRD) data from the CheMin instrument using the FULLPAT program have documented the presence of X-ray amorphous materials at multiple sites within Gale Crater, Mars. These materials are believed to be to be iron-rich based on chemical data, and at least some of them are believed to be weathering products based on volatile contents. However, the characteristics of these proposed Fe-rich weathering products remain poorly understood. To better understand these X-ray amorphous materials on Mars, we are 1) examining weathering products formed on Fe-rich parent material in terrestrial soils across a range of climatic conditions, and 2) performing burial experiments of Fe- and Mg- rich olivine in these soils. We describe each of these approaches below.