Basinal fluid flow systems and their relationships with mineralization - driving forces, paths and traps

基底流体流动系统及其与矿化的关系——驱动力、路径和圈闭

• 批准号: RGPIN-2018-06458
• 负责人: Chi, Guoxiang
• 金额: $ 2.62万
• 依托单位: University of Regina
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2022
• 资助国家: 加拿大
• 起止时间: 2022-01-01 至 2023-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=755032
• 关键词: Basinal; fluid; flow; systems; their

Many mineral deposits formed from circulation of geologic fluids in sedimentary basins. Understanding the operation mechanisms of these fluid flow systems, including their driving forces, paths and reaction with various lithologies and/or fluids leading to precipitation of ore minerals (traps), is important for mineral exploration. The primary goal of my research is to enhance our understanding of these basinal mineralization systems and to establish tools or geologic criteria that can help identify favorable locations for mineralization. The proposed research focuses on uranium mineralization associated with the Athabasca Basin in northern Saskatchewan, which contains the richest uranium deposits in the world. Since the first discovery of this type of uranium deposits (named unconformity-type because they occur near the unconformity between the basin and its basement) in the Athabasca Basin nearly 50 years ago, extensive studies have been carried out and a comprehensive mineralization model (called the diagenetic-hydrothermal model) has been established. Generations of geoscientists have been continuously making effort to improve the mineralization model in order to better guide exploration and increase the success rate. In my previous Discovery Grant, my research team has found evidence suggesting that the uranium mineralization in the Athabasca Basin may have taken place at much shallower depths ( 5km), and that the limited distribution of uranium-rich fluids, rather than the availability of reducing agents required to precipitate uraninite (as implied in the conventional exploration model), was the key factor determining whether or not and where uranium deposits may form. Furthermore, it was found that fluid flow related to uranium mineralization was controlled by reactivated basement faults, not only because these faults may be used as conduits, but also because they can control the location of fluid convection cells and can episodically provide the driving force for fluid flow that can explain the ingress and egress flow patterns demonstrated by the mineralization features. Based on these findings, we propose to carry out new research to further delineate the timing of uranium mineralization and basinal brine (parent of the ore-forming fluid) development, the possible paths of the brine from the upper part to the basal part of the basin and the basement, the hydrodynamic relationships between the basinal brine and basement faults (both shallow- and deep-seated), and physical and chemical traps that promote channeling of uranium-rich fluids and their reaction with reducing agents (either in fluid or rock). The results will refine the mineralization model to better guide exploration. The research is important for Canada as the second largest uranium producer in the world and one of the leading countries in uranium geology study.

许多是由沉积盆地地质流体循环形成的矿藏。了解这些流体流系统的运行机制，包括它们的驱动力，路径和反应，以及导致矿石矿物（陷阱）沉淀的各种岩性和/或流体，对于矿物勘探很重要。我的研究的主要目的是增强我们对这些基础矿化系统的理解，并建立可以帮助识别有利位置的工具或地质标准。拟议的研究重点是与萨斯喀彻温省北部的Athabasca盆地相关的铀矿化，其中包含世界上最富有的铀沉积物。自从近50年前，自第一次发现这种类型的铀沉积物（称为不合格类型，因为它们发生在盆地和其地下室之间的不整体范围内）以来，已经进行了广泛的研究（称为伊斯特氏菌 - 氢层模型）。几代地球科学家一直在不断努力改善矿化模型，以便更好地指导探索并提高成功率。在我以前的发现赠款中，我的研究团队发现了证据表明，阿萨巴斯卡盆地中的铀矿化可能是在较浅的深度（5km）处进行的，并且富含铀的液体的分布有限，而不是减少脉络脉络脉络脉络脉络脉络脉络脉络脉络脉络脉络脉络脉络脉络脉络的含量（是否是在传统勘探模型中）是否确定了脉络脉的脉络脉络，或者是脉络脉络的决定性脉络，是否是脉络脉络的决定性脉冲，或者是脉络脉的确定性。此外，发现与铀矿化有关的流体流由重新激活的地下室故障控制，这不仅是因为这些断层可以用作导管，还因为它们可以控制流体对流细胞的位置，并且可以在情节上提供流体流动的驱动力，可以解释矿化特征所用矿化的流动模式。 Based on these findings, we propose to carry out new research to further delineate the timing of uranium mineralization and basinal brine (parent of the ore-forming fluid) development, the possible paths of the brine from the upper part to the basal part of the basin and the basement, the hydrodynamic relationships between the basinal brine and basement faults (both shallow- and deep-seated), and physical and chemical traps that promote channeling of富含铀的液体及其与还原剂（在液体或岩石中）的反应。结果将完善矿化模型，以更好地指导探索。这项研究对于加拿大作为世界第二大铀生产国也很重要，也是铀地质研究的主要国家之一。