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: 2020
• 资助国家: 加拿大
• 起止时间: 2020-01-01 至 2021-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=711108
• 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).

该研究计划的重点是纽芬兰（NL）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）的类似地体中的多个区域广泛的成矿事件。迄今为止，我们在荷兰阿瓦隆地体中至少发现了三个不同的花岗岩类深成体活动（约 620 Ma、585-575 Ma 和 565 Ma），它们显示出作为与侵入相关的矿床的肥沃期的潜力。这些矿产资源的经济潜力尚未得到充分审查和勘探。该计划将提供该地体内浅层浅成热液金银矿床和相关斑岩铜金矿床特征的详细表征，包括对主火山-沉积岩的时间、沉积环境和构造亲和力的确定和母岩体。这些知识将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： - 对主岩进行岩相学、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事件同时发生的弧火山活动的确切类型有关。 - 母花岗岩和附属火山岩的 U-Pb 地质年代学，以及辉钼矿成矿的 Re-Os 地质年代学，以确定成矿事件的明确时间。 它将强调先进微分析技术的开发和应用，特别是 - 硫同位素微量分析，特别是辨别与浅成热液矿化有关的黄铁矿与与矿石沉积同时发生的近地表（或浅地表下）火山口内水域沉积物中生物沉淀的黄铁矿。 - 对页硅酸盐矿物进行宏观（可见光/红外反射光谱（VIRS））和微观尺度分析的综合分析，以模拟矿床规模的蚀变类型和分区。这将包括拉曼光谱的进步，包括微米级到纳米级尖端增强拉曼光谱（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小体积的蚀变，从而能够更深入地了解这些系统中金银沉淀的机制。 该研究计划旨在提供 HQP（高素质人员）培训和地球科学，推动矿产勘探创新。本研究中开发的知识可直接应用于阿瓦隆地体矿藏的有效勘探、开发和开采。长期目标是加强对埃迪卡拉时期（635-541Ma）第一个后生动物群出现期间的地下古环境的了解。