The observations and conclusions are based on a study of uranium deposits in Weld County, Colorado. The deposits occur along geochemical interfaces (roll fronts) in the sandstones of the Fox Hills and Laramie formations of Late Cretaceous age.

The uranium deposits are epigenetic and were formed by solutions moving down through a pre-Oligocene unconformity developed on the gently dipping Cretaceous strata in the southern part of the Cheyenne basin.

Uranium solution mining has become important as a means of exploiting roll-front deposits with geologic and hydrologic characteristics amenable to controlled solution flow.

The interaction between exploration and mine development in evaluating the technical, economic, and environmental feasibility is of paramount importance for a successful solution mining project. Exploration provides data such as total reserves, minable reserves, lithology, thorough interpretation of geophysical logs, and geohydrologic observations to assist mine development in establishing well field patterns, mine economics, well completion methods, and solution control and containment methods. Mine development aids exploration by providing information generated during metallurgical testing, groundwater evaluation, mining, and aquifer restoration. In particular, radon and gross alpha activity measurements which are made in the groundwater prior to mining are significantly valuable in developing the ore body, and in regional exploration in similar lithologies.

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