Date of Award
Unconformity-related uranium (URU) deposits are the most profitable uranium deposits in the world. Among those deposits, the Athabasca Basin hosts the world’s largest high-grade uranium deposits. A series of numerical experiments regarding the effect of uranium source location, fault location, and fault dip angle on the formation of URU deposits have been conducted by using software TOUHREACT.
Simulation results suggest that although both sandstone-sourced and basement-sourced models can generate economical deposits, basement-sourced models are more likely to form larger deposits since uranium-carrying fluid only needs to move a shorter distance to reach the structural trap for further ore forming reaction.
Numerical modeling reveals that the fault location can significantly affect uranium deposits' location and mineralization. When the fault exists in the sandstone unit and basement unit, more deposits can form in the basement unit since ore forming fluid can easily transport through the fault zone between those two units. The fault dip angle can rearrange convection cells within the sandstone unit, impacting the temperature distribution near the unconformity interface and the uranium precipitation. Subvertical and 45-degree dip angle faults are favorable for transport of ore forming fluids to produce economical deposits. When the fault has a smaller dip angle, however, it aligns more closely to the unconformity interface, impeding the interaction of the basinal oxidizing fluid with the basement-derived reducing fluid to form uranium deposits.
Shen, Jiayue, "Numerical Modeling of Controlling Factors for Formation of Unconformity-Related Uranium Deposits in Sedimentary Basins" (2021). Electronic Theses and Dissertations. 8642.