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

铀是重要的能源来源，加拿大是世界第二大铀生产国。目前，加拿大的所有铀生产都来自萨斯喀彻温省北部阿萨巴斯卡盆地的高品位铀矿床，即与不整合有关的铀矿床。其中许多矿床是在一个经验模型的基础上发现的，即铀矿化发生在横切盆地和基底之间不整合的断层附近，在那里含铀氧化流体与还原剂相遇并与之反应，特别是石墨和从中产生的碳氢化合物。然而，随着勘探程度的提高，这一模式面临着越来越多的挑战，需要更好地了解控制成矿的因素。大型富铀矿床的形成需要大量含铀流体通过一个或多个铀沉淀机制有效地从流体中除去铀的有限区域。这涉及到可以用数值方法模拟的热-水力-机械-化学(THMC)过程。如果建立正确的数值模型，可以用来预测有利的成矿点。为了找到正确的THMC模型，必须使用不同的物理和化学参数进行多个方案的数值模拟，并将模拟结果与地质观测结果进行对比验证。因此，选择一个积累了大量与成矿有关的地质数据的研究区是很重要的。之所以选择阿萨巴斯卡盆地东北部作为研究对象，是因为在该地区发现了一批世界级铀矿床，并从围岩岩性、基底构造、蚀变、矿体几何和分布等方面对许多铀矿床进行了详细的研究。研究结果将有助于赞助商(Areva Resources Canada Inc.)与其他铀矿勘探公司合作寻找更多铀矿，这将有助于为偏远的北方社区创造就业机会和经济繁荣。

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.