Metallogeny of the Avalon Terrane During the Late Neoproterozoic

新元古代晚期阿瓦隆地体成矿作用

• 批准号: RGPIN-2017-05037
• 负责人: Layne, Graham
• 金额: $ 1.6万
• 依托单位: Memorial University of Newfoundland
• 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=751150
• 关键词: Metallogeny; Avalon; Terrane; During; Late

This research program is focused on multiple, regionally extensive, metallogenetic episodes in the Neoproterozoic Avalon Terrane in Newfoundland (NL), and closely equivalent terranes in Nova Scotia (Mira Terrane) and New Brunswick (Caledonia Terrane). To date we recognize at least three distinct episodes of granitoid plutonism within the Avalon Terrane of NL (ca. 620 Ma, 585-575 Ma and 565 Ma) that show potential as fertile episodes for intrusion-related mineral deposits. These are under-examined, and under-explored, in terms of their potential for economic mineral resources. The program will provide detailed characterization of the features of both shallow epithermal Au-Ag and related porphyry-Cu(-Au) deposits within this terrane, incorporating determinations of the timing, depositional environment, and tectonic affinity of both the host volcano-sedimentary rocks and the parent plutons. This knowledge will be used to inform models for evolution of the Avalon Terrane in Atlantic Canada.The scientific and technical approach will include:- Petrographic, lithogeochemical and radiogenic isotope analysis (Nd) of host rocks, with particular relevance to establishing the exact style of arc volcanism that was contemporaneous with episodes of ore formation.- U-Pb geochronology of parent granitoids and affiliated volcanic rocks, and Re-Os geochronology of molybdenite mineralization, to determine explicit timing of ore-forming events.It will emphasize development and application of advanced microanalytical technologies, in particular,- Sulfur isotope microanalysis, specifically to discern pyrite genetically associated with epithermal ore mineralization from that biogenically precipitated in sediments in near-surface (or shallow subsurface) intra-caldera waters contemporaneous with ore deposition.- Integrated macro- (Visible/Infrared Reflectance Spectroscopy (VIRS)) and micro-scale analysis of phyllosilicate minerals to model alteration styles and zoning at the deposit scale. This will include advancement of Raman Spectroscopy, including micro- to nano-scale Tip Enhanced Raman Spectroscopy (TERS), for the study of alteration minerals in ore deposits. TERS has exciting potential to characterize extremely small volumes of alteration intimately associated with precious metal mineralization, enabling a deeper understanding of the mechanisms of Au-Ag precipitation in these systems.The research program is designed to provide HQP (Highly Qualified Personnel) training and geoscience that drives innovation in mineral exploration. The knowledge developed in this study is directly transferable to the effective exploration, development and mining of mineral deposits in the Avalon Terrane. A longer term goal is to enhance understanding of the subaerial paleo-environment during the emergence of the first metazoan fauna in the Ediacaran period (635-541Ma).

本研究项目重点研究了纽芬兰新元古代阿瓦隆地体以及新斯科舍省（米拉地体）和新不伦瑞克省（喀里多尼亚地体）的多期、区域性广泛的成矿事件。迄今为止，我们在NL的Avalon地块内发现了至少三个不同的花岗岩类深部成矿时期（约620 Ma， 585-575 Ma和565 Ma），这些时期显示出与侵入有关的矿床的肥沃时期的潜力。就其经济矿产资源的潜力而言，这些地区没有得到充分审查和开发。该项目将提供该地块内浅层浅成低温热液Au-Ag和相关斑岩- cu （-Au）矿床的详细特征，包括确定时间、沉积环境和宿主火山沉积岩和母岩的构造亲和性。这些知识将被用来为加拿大大西洋地区阿瓦隆地层的演化模型提供信息。科学和技术方法将包括：-寄主岩石的岩石学、岩石地球化学和放射性成因同位素分析（Nd），特别是与确定与成矿时期同时期的弧火山作用的确切类型有关。-母花岗岩及其附属火山岩的U-Pb年代学和辉钼矿成矿的Re-Os年代学，以确定成矿事件的明确时间。它将强调先进的微分析技术的发展和应用，特别是硫同位素微分析，特别是从与矿沉积同时发生的近地表（或浅地下）火山口内水域沉积物中生物成因沉淀的黄铁矿中，识别与浅热液矿化有关的黄铁矿。综合宏观（可见/红外光谱）和微观尺度分析层状硅酸盐矿物，以模拟矿床尺度上的蚀变样式和分带。这将包括拉曼光谱的进步，包括微到纳米尺度的尖端增强拉曼光谱（TERS），用于研究矿床中的蚀变矿物。TERS具有令人兴奋的潜力，可以表征与贵金属矿化密切相关的极少量蚀变，从而更深入地了解这些系统中Au-Ag沉淀的机制。该研究项目旨在提供HQP（高素质人才）培训和推动矿产勘探创新的地球科学。研究成果对有效勘探、开发和开采阿瓦隆地体矿床具有直接指导意义。长期目标是加强对埃迪卡拉纪（635-541Ma）第一批后生动物群出现期间陆地古环境的认识。