Precambrian crustal growth in the Canadian shield: investigating a billion year of tectono-magmatic evolution in the Winnipeg River subprovince, Ontario, Canada

加拿大地盾中的前寒武纪地壳生长：调查加拿大安大略省温尼伯河副省十亿年的构造岩浆演化

• 批准号: RGPIN-2021-03199
• 负责人: Perrouty, Stéphane
• 金额: $ 2.19万
• 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: 2021
• 资助国家: 加拿大
• 起止时间: 2021-01-01 至 2022-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=742431
• 关键词: Precambrian; crustal; growth; Canadian; shield

Plate tectonics (i.e., plate movement and interaction) occurred throughout all Earth's history, but driving forces and associated processes evolved during the Archean and Proterozoic eons, and resulted in global tectonic, magmatic, and environmental changes. Ultimately, these changes have implications on the nature, abundance and spatial distribution of base (e.g., Ni, Cu, Zn), precious (e.g., Au) and strategic (e.g., Li-REE-Nb-Ta) metal deposits in Precambrian shields. Each continental crust fragment of Precambrian age represents a piece of the puzzle, however their integration in a unified, global-scale, plate tectonics evolutionary model is challenging. The long term objective of this research program is to use multi-disciplinary approaches to propose a comprehensive geodynamic interpretation of the Canadian shield, and test it against other well documented Precambrian cratons in South Africa, Australia, West Africa and South America. The Canadian shield is an ideal study area that includes some of the largest Archean crustal fragments (e.g., Superior Province) that are bounded by extensive Paleoproterozoic orogenic belts (e.g., Trans-Hudson), and displays a nearly continuous crustal growth and recycling spanning half of the Earth's history (i.e., from 4.0 Ga to 1.8 Ga). In this program, the emphasis will be on the structural, metamorphic and geochemical evolution of the Precambrian continental crust, and its implications to prospect for natural resources. In the next five years, the short term objective is to unravel a billion year of Archean crustal history in the Winnipeg River subprovince, between Sioux Lookout and Kenora, north-western Ontario. The variety of ages, rocks types, structural patterns and metamorphic grades in the Winnipeg River subprovince makes it an appropriate study area to decipher the broader geodynamic evolution of the western Superior Province. This research program will: (1) develop a new understanding of crustal growth and recycling in the Winnipeg River subprovince, using structural, geochronological, lithogeochemical, and metamorphic constraints; (2) recognize possible secular geodynamic changes between the Paleo- Meso- and Neoarchean evolution of the Winnipeg River subprovince; (3) propose a revised tectono-stratigraphic model of the western Superior Province, and test its implications for Archean geodynamic processes, which will be a first step toward the long term objective of this research program; (4) deliver a comprehensive and multi-disciplinary study of a gneiss-granitoid "pinkstone" belt in the Superior Province, with integrated investigations on the origin and distribution of strategic metal occurrences, which may assist future exploration projects and ultimately enhance the mineral resources potential of north-western Ontario.

板块构造（即板块运动和相互作用）贯穿于整个地球历史，但驱动力和相关过程在太古宙和元古宙演化，导致了全球构造、岩浆和环境的变化。这些变化最终影响了前寒武纪盾构中碱性金属（如Ni、Cu、Zn）、贵重金属（如Au）和战略金属（如Li-REE-Nb-Ta）矿床的性质、丰度和空间分布。每个前寒武纪的大陆地壳碎片都代表了这个谜题的一部分，然而，将它们整合到一个统一的、全球规模的板块构造演化模型中是具有挑战性的。该研究项目的长期目标是使用多学科方法对加拿大地盾进行全面的地球动力学解释，并与南非、澳大利亚、西非和南美洲的其他有充分记录的前寒武纪克拉通进行测试。加拿大地盾是一个理想的研究区域，它包括一些最大的太古宙地壳碎片（如苏伯勒省），被广泛的古元古代造山带（如跨哈德逊）所包围，并显示出跨越地球历史一半（即从4.0 Ga到1.8 Ga）的几乎连续的地壳生长和再循环。本项目将重点研究前寒武纪大陆地壳的构造、变质作用和地球化学演化及其对自然资源勘探的意义。在接下来的五年里，短期目标是揭开位于安大略省西北部苏了望和基诺拉之间的温尼伯河亚省10亿年的太古宙地壳历史。温尼伯河亚省在时代、岩石类型、构造模式和变质等级等方面的多样性，使其成为揭示苏必利尔省西部更广泛的地球动力学演化的合适研究区域。本研究项目将：(1)利用构造、年代学、岩石地球化学和变质学约束，对温尼伯河省的地壳生长和再循环进行新的认识；(2)认识到温尼伯河亚省古-中-新太古代演化之间可能存在的长期地球动力学变化；(3)提出了苏必利尔省西部构造地层修正模型，并验证了该模型对太古宙地球动力学过程的影响，为实现本研究的长期目标迈出了第一步；(4)对苏必利尔省的片麻岩-花岗质“粉红岩”带进行全面的多学科研究，并对战略金属赋存地的起源和分布进行综合调查，这可能有助于未来的勘探项目，最终提高安大略省西北部的矿产资源潜力。