Deconvoluting the fundamental processes of metal migration from ore deposits; source to sink

对金属从矿床迁移的基本过程进行解卷积；

• 批准号: RGPIN-2016-05910
• 负责人: Leybourne, Matthew
• 金额: $ 1.75万
• 依托单位: Laurentian University of Sudbury
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2016
• 资助国家: 加拿大
• 起止时间: 2016-01-01 至 2017-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=615982
• 关键词: Deconvoluting; fundamental; processes; metal; migration

My research focuses on deciphering the mechanisms and processes by which metals and metalloids migrate from buried mineralization to the surface through thick cover. This work is important because most near surface mineral deposits have been discovered; exploration needs to extend to greater depth. Furthermore, these metal migration processes also have significant in understanding human and ecosystem health. Currently, my research team includes 3 PDF, 2 PhD, 7 MSc and 2 BSc students (some co-supervised). This team will increase with the 2 PhD, 3 MSc and 5 BSc students included in this proposal. My team’s work has revealed that metals can migrate through thick cover via different mechanisms based on the climate, seismicity and groundwater composition. Although we have been able to add much to the understanding of metal migration through thick cover, a number of theoretical and practical questions remain unanswered, including 1) the importance of ionic and electrochemical transport, including the role of microbes; 2) how metals and metalloids are sequestered in surface; and 3) how thick cover influences exploration techniques and mitigation of water and soil contamination. The key to answering these questions and understanding element migration processes requires a multidisciplinary approach (geochemistry, geology, microbiology, and soil science) that operates from the nano- and micron-scale (laser ablation, SEM, TEM) to the scale of an ore deposit. To address these questions I propose research using two field sites; the Martiniere deposit (Ontario) is a mixed Au and base metal deposit with thick till cover and the Sisson W-Mo deposit is dominated by metalloids (i.e., W, Mo, Tl). Field techniques (in situ pH, Eh, redox sensitive species) and samples (i.e., soil, till, groundwater) will be augmented by laboratory experiments (column, redox, and adsorption) to determine and quantify vertical migration of metals through till. We will investigate in detail where metals are being sequestered and what happens under variable conditions of water-rock-soil interaction in different geological media. Another key aspect of this research will be to use traditional and non-traditional isotopic techniques (e.g., Pb, Se, Cu, Fe) to quantify redox processes and better fingerprint metal sources. This project will involve developing sampling protocols to preserve the speciation of these metalloids as they migrate away from the ore deposit source and undergo changes in redox and water chemistry. This research will lead to new understanding of metal versus metalloid speciation and migration, refinement of models for migration of metals through thick cover, and novel approaches to understanding geochemical baselines. The proposal will result in the training of HQP at the PhD, MSc and BSc level in state-of-the-art analytical methods, geochemical modeling and field protocols.

我的研究重点是破译金属和类金属通过厚覆盖层从埋藏矿化迁移到地表的机制和过程。这项工作很重要，因为大多数近地表矿床已经被发现;勘探需要延伸到更深的地方。此外，这些金属迁移过程对理解人类和生态系统健康也具有重要意义。目前，我的研究团队包括3个PDF，2个博士，7个硕士和2个学士学位的学生（一些共同监督）。该团队将增加2名博士，3名硕士和5名理科学生。 我的团队的工作表明，金属可以通过基于气候、地震活动和地下水成分的不同机制在厚覆盖层中迁移。虽然我们已经能够增加很多金属迁移通过厚覆盖层的理解，一些理论和实践问题仍然没有答案，包括1）离子和电化学运输的重要性，包括微生物的作用; 2）金属和类金属是如何在表面隔离; 3）厚覆盖层如何影响勘探技术和减轻水和土壤污染。 回答这些问题和理解元素迁移过程的关键需要多学科方法（地球化学，地质学，微生物学和土壤科学），从纳米和微米尺度（激光消融，SEM，TEM）到矿石存款的规模。为了解决这些问题，我建议使用两个现场进行研究; Martiniere存款（安大略省）是一个混合的Au和贱金属存款，具有厚的冰碛物覆盖层，Sisson W-Mo存款主要由非金属（即，W，Mo，T1）。现场技术（原位pH、Eh、氧化还原敏感物质）和样品（即，土壤、耕层、地下水）将通过实验室实验（柱、氧化还原和吸附）进行补充，以确定和量化金属通过耕层的垂直迁移。我们将详细调查金属被封存的位置以及在不同地质介质中水-岩-土壤相互作用的不同条件下会发生什么。这项研究的另一个关键方面将是使用传统和非传统的同位素技术（例如，Pb，Se，Cu，Fe）来量化氧化还原过程和更好的金属来源指纹。该项目将涉及制定采样协议，以保护这些类金属的形态，因为它们迁移远离矿石存款来源，并经历氧化还原和水化学的变化。 这项研究将导致对金属与类金属形态和迁移的新理解，金属通过厚盖层迁移模型的改进，以及理解地球化学基线的新方法。该提案将导致在最先进的分析方法，地球化学建模和现场协议方面对博士，硕士和学士水平的HQP进行培训。