Thermal - hydrolic - mechanical - chemical (THMC) modeling of fluid flow and its control on localization of uranium deposits in the northeastern Athabasca basin, Saskatchewan

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Uranium is an important source of energy, and Canada is the second largest uranium producer in the world. Currently all the uranium production in Canada is from high-grade uranium deposits known as unconformity-related uranium deposits in the Athabasca Basin in northern Saskatchewan. Many of these deposits were discovered based on an empirical model that uranium mineralization took place near faults crosscutting the unconformity between the basin and the basement, where uranium-bearing oxidizing fluids met and reacted with reducing agents, especially graphite and hydrocarbons derived from it. However, with increasing degrees of exploration, this model is facing more and more challenges, and a better understanding of the factors controlling mineralization is needed. The formation of large and rich uranium deposits requires that a large amount of uranium-bearing fluids passed through limited areas where one or more uranium precipitation mechanisms effectively removed uranium from the fluids. This involves thermal - hydraulic - mechanical - chemical (THMC) processes that may be simulated using numerical methods. The numerical models, if correctly established, can be used to predict favourable mineralization sites. In order to find the correct THMC model, multiple scenarios of numerical modeling using different physical and chemical parameters must be carried out and verified by comparing the modeling results with geological observations. It is therefore important to select a study area where much geological data relevant to mineralization have been accumulated. The northeastern part of the Athabasca Basin is chosen for this study because a number of world-class uranium deposits have been discovered in this area, and many of them have been studied in detail in terms of host rock lithology, basement structure, alteration, and orebody geometry and distribution. The research results will help the sponsor (Areva Resources Canada Inc.) and other uranium exploration companies to find more uranium deposits, which will contribute to job creation and economic prosperity for isolated northern communities.