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).

该研究项目的重点是纽芬兰（NL）新元古代阿瓦隆地体的多个区域性广泛成矿事件，以及新斯科舍省（米拉地体）和新玩法（喀里多尼亚地体）的密切等同的成矿事件。到目前为止，我们认识到至少有三个不同的花岗岩类深成岩情节内的阿瓦隆地体的NL（约。620 Ma，585-575 Ma和565 Ma），显示了与侵入有关的矿床的肥沃幕。就其作为经济矿物资源的潜力而言，这些都没有得到充分的审查和开发。该计划将提供该区域内浅成低温热液金银矿床和相关斑岩铜（-Au）矿床特征的详细表征，包括确定时间、沉积环境以及寄主火山沉积岩和母岩体的构造亲和性。这些知识将被用于为加拿大大西洋阿瓦隆地体的演化模型提供信息。科学和技术方法将包括：-寄主岩石的岩相学、岩石地球化学和放射性同位素分析（Nd），特别是与确定与成矿期同时发生的弧火山作用的确切类型有关。母岩和火山岩的U-Pb年代学和辉橄榄岩成矿的Re-Os年代学，以确定成矿事件的明确时间，重点发展和应用先进的微区分析技术，特别是硫同位素微区分析，特别是识别与浅成低温热液成矿成因有关黄铁矿和近地表沉积物中的生物沉淀黄铁矿（或浅层地下）与矿石沉积同时存在的破火山口内沃茨。对页硅酸盐矿物进行宏观（可见/红外反射光谱（VIRS））和微观分析，以模拟存款规模的蚀变类型和分带。这将包括拉曼光谱学的进步，包括微纳米级尖端增强拉曼光谱学（TERS），用于研究矿床中的蚀变矿物。TERS在表征与贵金属矿化密切相关的极少量蚀变方面具有令人兴奋的潜力，能够更深入地了解这些系统中的金银沉淀机制。该研究计划旨在提供HQP（高素质人员）培训和推动矿产勘探创新的地球科学。本研究中开发的知识可直接用于阿瓦隆地体矿床的有效勘探、开发和开采。一个长期的目标是加强对埃迪卡拉纪（635- 541 Ma）第一批后生动物群出现期间的陆上古环境的了解。