A genetic model and geochemical exploration tools for magnetite-apatite REE deposits

磁铁矿-磷灰石稀土矿床的成因模型和地球化学勘探工具

• 批准号: 537218-2018
• 负责人: WilliamsJones, Anthony
• 金额: $ 2.79万
• 依托单位: McGill University
• 依托单位国家: 加拿大
• 项目类别: Collaborative Research and Development Grants
• 财政年份: 2021
• 资助国家: 加拿大
• 起止时间: 2021-01-01 至 2022-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=720251
• 关键词: genetic; model; geochemical; exploration; tools

The heavy rare earth elements (HREE) and Nd are of strategic importance because of their application in new technologies designed to address the issue of global warming, and are critical raw materials for future economic development. Because there are no major producers of these metals outside China, Focus Graphite Inc. has a significant opportunity to exploit the potential resources of the Kwyjibo magnetite-apatite REE deposits (Québec). The proposed research builds on research undertaken through the NSERC Engage program and aims to formulate a comprehensive model for the genesis of the deposits and develop tools that could be used in their ongoing exploration. In contrast to most base and precious metal ore systems, for which robust genetic models have been developed, we have a poor understanding of how the REE are concentrated to economic levels, and almost no understanding of how this occurs in magnetite-apatite rocks. Indeed, even the genesis of magnetite-apatite rocks is a matter of debate, with opinion being divided over whether they are magmatic or hydrothermal in origin. Moreover, many of them have sub-economic concentrations of the REE. The Kwyjibo deposits are exceptional in having high concentrations of the REE, particularly the HREE. This may be because they experienced subsequent hydrothermal alteration that remobilised the REE and could have introduced additional REE resources. We plan to study the magnetite-apatite rocks and their hydrothermally altered equivalents using the results of a combination of major and trace element analyses of the bulk rocks, minerals and, if present, melt and fluid inclusions. These data will be complemented by results of analyses of the stable and radiogenic isotope chemistry of mineral separates and bulk rocks. In addition, we will conduct microthermometric analyses of fluid inclusions and thermodynamic modelling. The sum of these activities will allow us to determine the genesis of the magnetite-apatite rocks, the source of the REE, and how hydrothermal fluids mobilised the REE. Through an analysis of the mineral chemistry, the project should also yield tools for the exploration and discovery of similar deposits both locally and elsewhere in Canada.

重稀土元素（HREE）和钕具有战略重要性，因为它们应用于旨在解决全球变暖问题的新技术，并且是未来经济发展的关键原材料。由于中国以外没有这些金属的主要生产商，福克斯石墨公司。拥有开发Kwyjibo磁铁矿-磷灰石REE矿床（魁北克）潜在资源的重要机会。拟议的研究建立在通过NSERC Engage计划进行的研究的基础上，旨在制定矿床成因的综合模型，并开发可用于正在进行的勘探的工具。相反，大多数基地和贵金属矿石系统，其中强大的成因模型已经开发，我们有一个贫穷的了解如何稀土元素集中到经济水平，几乎没有了解这是如何发生在磁铁矿-磷灰石岩石。事实上，甚至磁铁磷灰石岩石的成因也是一个有争议的问题，人们对它们是岩浆还是热液起源有分歧。此外，其中许多国家的稀土元素浓度低于经济水平。Kwyjibo矿床具有高浓度的稀土元素，特别是重稀土元素。这可能是因为它们经历了随后的热液蚀变，使REE重新活化，并可能引入了额外的REE资源。我们计划研究磁铁磷灰石岩石和它们的热液蚀变等价物的组合的主要和微量元素的分析结果的散装岩石，矿物，如果存在的话，熔体和流体包裹体。这些数据将得到矿物分离物和大块岩石的稳定和放射性同位素化学分析结果的补充。此外，我们将进行流体包裹体的显微测温分析和热力学建模。这些活动的总和将使我们能够确定磁铁矿-磷灰石岩石的成因，稀土元素的来源，以及热液流体如何动员稀土元素。通过对矿物化学的分析，该项目还将为在加拿大当地和其他地方勘探和发现类似矿床提供工具。