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).

该研究计划集中于纽芬兰(NL)新元古代阿瓦隆地体(NL)以及新斯科舍省(Mira Terrane)和新不伦瑞克(喀里多尼亚Terrane)密切对应的地体中的多个区域性广泛的成矿事件。到目前为止，我们在西北部阿瓦隆地体(约620 Ma、585-575 Ma和565 Ma)内至少识别出三个不同的花岗岩类深成岩幕，显示出与侵入体有关的矿藏的潜在富集期。就其经济矿产资源的潜力而言，这些资源没有得到充分的研究和开发。该计划将提供该地体内浅层浅成热液Au-Ag和相关斑岩-铜(-Au)矿床的详细特征，包括对寄主火山-沉积岩和母岩体的时间、沉积环境和构造亲和力的确定。这些知识将被用来为加拿大大西洋阿瓦隆地体的演化模式提供信息。科学和技术方法将包括：-对容矿岩石进行岩石学、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事件同时发生的弧火山作用的确切样式有关。-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。它将强调先进微观分析技术的开发和应用，特别是硫同位素微量分析。具体地说，从与成矿同时在近地表(或浅层地下)破火山口内水域的沉积物中生物沉积的黄铁矿中辨别与低温热液成矿有关的黄铁矿。-层状硅酸盐矿物的综合宏观(可见光/红外反射光谱)和微观尺度分析，以模拟矿床规模的蚀变类型和分带。这将包括拉曼光谱学的进展，包括微米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具有描述与贵金属矿化密切相关的极少量蚀变的令人兴奋的潜力，使人们能够更深入地了解这些系统中Au-Ag沉淀的机制。该研究计划旨在提供HQP(高素质人员)培训和地球科学，以推动矿产勘探的创新。本研究开发的知识可直接用于有效勘探、开发和开采Avalon Terrane的矿藏。一个较长期的目标是加强对埃迪卡拉纪(635-541 Ma)第一个后生动物出现期间空中古环境的了解。