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部的阿萨巴斯卡盆地。该盆地的铀矿床位于盆地与基底之间的不整合面附近，被称为“不整合型”或“不整合相关型”。在加拿大和世界其他地方也开发了类似的矿床。长期以来，人们认识到所有与不整合相关的铀矿床都与基底断层的再活化有关，但为什么大多数基底断层是秃的，而只有一小部分再活化的基底被矿化，却一直没有得到很好的理解。因此，确定活化基底断裂中铀成矿的控制因素对铀勘探具有重要意义。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、地球化学和水动力学研究来破译控矿因素，该地区拥有几个已知的矿床，并由该研究项目的工业赞助商Orano Canada积极勘探新的铀资源。拟开展的研究包括六个部分：1)三维地质建模；2)岩石学和共生研究；3)流体温度-压力-成分表征；4)地球化学反应路径建模；5)流体流动建模；6)反应性质量输运建模。研究结果将用于评估流体通道和流体-流体和/或流体-岩石反应的最佳条件，从而有效地沉淀和富集铀矿石。这项研究将有助于Orano和其他勘探公司在阿萨巴斯卡盆地和其他具有类似地质条件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.