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: 2019
• 资助国家: 加拿大
• 起止时间: 2019-01-01 至 2020-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=687254
• 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 Nd 具有战略重要性，因为它们在旨在解决全球变暖问题的新技术中得到了应用，并且是未来经济发展的关键原材料，因为这些金属之外没有主要生产商。中国，Focus Graphite Inc. 拥有开发 Kwyjibo 磁铁矿-磷灰石稀土矿床（魁北克）潜在资源的重大机会。拟议的研究以 NSERC Engage 计划开展的研究为基础，旨在制定一个综合模型。与大多数已开发出强大遗传模型的基础金属和贵金属矿石系统相比，我们对稀土元素如何集中的了解甚少。事实上，甚至磁铁矿-磷灰石岩石的成因也存在争议，人们对它们是岩浆还是热液的起源存在分歧。他们中有奎吉博矿床的稀土元素浓度很高，尤其是重稀土元素，这可能是因为它们经历了随后的热液蚀变，重新激活了稀土元素，并可能引入了额外的稀土元素磁铁矿-磷灰石。岩石及其热液蚀变等效物，使用对大块岩石、矿物以及熔体和流体包裹体（如果存在）的主量元素和微量元素分析的组合结果，这些数据将得到补充。矿物分离物和块体岩石的稳定和放射性同位素化学分析结果此外，我们还将对流体包裹体进行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，以及热液如何动员稀土元素。通过对矿物化学的分析，该项目还应该为加拿大当地和其他地方的类似矿床的勘探和发现提供工具。