Factors controlling the formation and localization of reverse-offset unconformity-related uranium deposits along the Midwest Trend, Athabasca Basin, northern Saskatchewan

铀矿开采是加拿大采矿业的重要组成部分，目前加拿大所有的铀生产都来自萨斯喀彻温省北方的阿萨巴斯卡盆地。该盆地铀矿床位于盆地与基底不整合面附近，称之为“不整合型”或“与不整合有关”铀矿床。加拿大其他地方和世界其他地区也有类似的矿床。长期以来，人们认识到所有与不整合面有关的铀矿床都与横切不整合面的再活化基底断裂有关，但为什么大多数基底断裂是贫瘠的，而只有少数再活化基底的一小部分被矿化，人们还没有很好地理解。因此，确定基底断裂活动对铀成矿的控制因素对铀矿勘查具有重要意义。拟议的研究旨在通过对中西部趋势（位于东北阿萨巴斯卡盆地）进行详细的地质、地球化学和流体动力学研究来解释控矿因素，该趋势拥有几个已知的矿床，并由本研究项目的工业赞助商Orano Canada积极探索新的铀资源。该研究由六个部分组成：1）三维（3D）地质建模，2）岩相学和共生研究，3）流体温度-压力-组成表征，4）地球化学反应路径建模，5）流体流动建模，和6）反应质量输运建模。研究结果将用于评价流体通道和流体-流体和/或流体-岩石反应导致铀矿有效沉淀和聚集的最佳条件。这项研究将帮助Orano和其他勘探公司在阿萨巴斯卡盆地和其他地质条件相似的盆地发现更多的铀矿床。

Uranium (U) mining is an important part of the mining industry in Canada and currently all the U production in Canada is from the Athabasca Basin in northern Saskatchewan. The U deposits in this basin are located near the unconformity between the basin and the basement, and are termed "unconformity-type" or "unconformity-related". Similar deposits are also developed elsewhere in Canada and other parts of the world. It has been recognized for a long time that all of the unconformity-related U deposits are associated with reactivated basement faults crosscutting the unconformity, but it has not been well understood why most of the basement faults are barren and only small portions of some of the reactivated basements are mineralized. Determining the factors that control U mineralization in reactivated basement faults is thus important for U exploration. The proposed research aims to decipher the ore-controlling factors through a detailed geological, geochemical and hydrodynamic study of the Midwest Trend (in NE Athabasca Basin), which hosts several known deposits and is actively explored for new U resources by Orano Canada, the industrial sponsor of this research project. The proposed research consists of six components: 1) three-dimensional (3D) geological modeling, 2) petrographic and paragenetic studies, 3) fluid temperature-pressure-composition characterization, 4) geochemical reaction path modeling, 5) fluid flow modeling, and 6) reactive mass transport modeling. The results will be used to evaluate the best conditions for fluid channelling and fluid-fluid and/or fluid-rock reaction leading to effective precipitation and accumulation of U ores. The research will help Orano and other exploration companies find more U deposits in the Athabasca Basin and other basins with similar geological conditions.