The significance of the silicification zones for the formation of unconformity-related uranium deposits in the Athabasca basin, Saskatchewan

硅化带对于萨斯喀彻温省阿萨巴斯卡盆地不整合面相关铀矿床形成的重要性

• 批准号: 529837-2018
• 负责人: Alexandre, Paul
• 金额: $ 2.04万
• 依托单位: Brandon University
• 依托单位国家: 加拿大
• 项目类别: Collaborative Research and Development Grants
• 财政年份: 2020
• 资助国家: 加拿大
• 起止时间: 2020-01-01 至 2021-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=697886
• 关键词: significance; silicification; zones; formation; unconformity

It is becoming increasingly difficult to discover new uranium deposits in the Athabasca Basin due to the increasing depth of undiscovered mineralization, which necessitates an even better understanding of their formation conditions and setting. One feature of these deposits that has never been systematically studied is the silicification zone, or "cap", present immediately above the deposits in the Athabasca Group sandstones. The purpose of this project is to ascertain what the role, if any, this silicification played in the formation of the unconformity-related uranium deposits and to establish how it can affect exploration efforts. To achieve these goals, the project will focus on two main topics: (1) Establishing the three-dimensional spatial extent of the silicification zone. This will be done using drill logs available at AREVA and in the public domain. Two main possibilities are: the silicification zone is strictly local and situated directly above a deposit, or it occurs on a regional scale and is not directly related to a deposit. (2) Establishing the physical and chemical conditions of formation and the temporal relationship between the silicification zone and the deposits' formation. This will be achieved using mostly mineralogical and geochemical methods, in particular stable isotopes on quartz overgrowths and quartz filling pore space, using Secondary Ion Mass Spectrometry (SIMS), and fluid inclusions. It is anticipated that the findings of this project will help relate, spatially and temporally, the silicification zone with style and intensity of alteration, desilicification, structural setting, petrology, and most importantly, uranium deposition. The area studied will primarily be the Martin Lake U prospect, which exhibits well-developed silicification zones, with possible extension to the McArthur River Zone 2 and Centennial deposits. Once the significance of the silicification for uranium deposition has been established, the results will be assessed, in conjunction with AREVA geologists, in terms of increased exploration efficiency.

在阿萨巴斯卡盆地发现新的铀矿变得越来越困难，因为未发现的矿化越来越深，这就需要更好地了解它们的形成条件和背景。这些矿床的一个从未被系统研究过的特征是硅化带，或“帽”，直接存在于阿萨巴斯卡组砂岩中的矿床上方。该项目的目的是确定这种硅化作用在不整合相关铀矿床的形成中所起的作用（如果有的话），并确定它如何影响勘探工作。 为实现这些目标，该项目将侧重于两个主要专题： (1)建立硅化带的三维空间范围。这将使用阿海珐和公共领域提供的钻井日志来完成。两种主要的可能性是：硅化带严格地是局部的，并且直接位于存款上方，或者它以区域规模出现，并且与存款不直接相关。 (2)建立了硅化带形成的物理化学条件及硅化带与矿床形成的时间关系。这将主要使用矿物学和地球化学方法来实现，特别是石英过度生长和石英填充孔隙空间的稳定同位素，使用二次离子质谱法（西姆斯）和流体包裹体。 预计该项目的研究结果将有助于在空间和时间上将硅化带与蚀变、脱硅化、构造背景、岩石学以及最重要的铀沉积的类型和强度联系起来。所研究的区域主要是马丁湖U前景，该区域显示出发育良好的硅化带，可能延伸到麦克阿瑟河2区和百年矿床。一旦确定了硅化作用对铀沉积的重要性，将与阿海珐地质学家一起从提高勘探效率的角度对结果进行评估。