“…Non-pedogenic calcretes and gypcretes have been identified and characterized in Australia, Europe, Africa, and (notably) in the western United States and Canada. As documented in mineral exploration surveys of broad uncontaminated areas, these accumulation zones contain the major constituents (calcite and/or gypsum) along with accessory minerals containing elements such as uranium (e.g., Peterson et al, 1985;Carlisle, 1978 and1980). Importantly, the topography and regional groundwater condition at Tuba City is closely akin to the sites where non-pedogenic mineral accumulation has been documented.…”