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)贯穿整个地球历史，但驱动力和相关过程在太古宙和元古界演化，并导致全球构造、岩浆和环境变化。最终，这些变化对前寒武纪屏蔽体中贱金属(如镍、铜、锌)、贵金属(如金)和战略金属(如Li-REE-Nb-Ta)的性质、丰度和空间分布产生了影响。前寒武纪的每个陆壳碎片代表着拼图的一部分，然而它们在统一的、全球范围的板块构造演化模型中的整合是具有挑战性的。这项研究计划的长期目标是使用多学科方法对加拿大地盾提出全面的地球动力学解释，并与南非、澳大利亚、西非和南美洲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，其中包括一些最大的太古代地壳碎片(例如，Superior省)，这些地壳碎片被广泛的古元古代造山带(例如，跨哈德逊)所包围，并显示出跨越地球历史一半时间(即从4.0Ga到1.8Ga)的几乎连续的地壳生长和再循环。在这个项目中，重点将放在前寒武纪大陆地壳的结构、变质和地球化学演化及其对自然资源勘探的意义上。在接下来的五年里，短期目标是在安大略省西北部的温尼伯河次省，在苏瞭望和克诺拉之间，揭开10亿年的太古宙地壳历史。温尼伯河亚省的时代、岩石类型、构造格局和变质等级的多样性，使其成为破译西部优胜省更广泛的地球动力学演化的合适研究区。这项研究计划将：(1)利用构造、地质年代学、岩石地球化学和变质约束，对温尼伯河亚省的地壳生长和再循环有新的认识；(2)认识温尼伯河亚省古-中-新太古代演化之间可能的长期地球动力学变化；(3)提出修正的西部优势省的构造地层模型，并检验其对太古宙地球动力学过程的影响，这将是迈向该研究计划长期目标的第一步；(4)对安大略省优胜省的片麻岩-花岗岩类“粉岩”带进行全面、多学科的研究，综合调查战略金属矿点的来源和分布，这可能有助于未来的勘探项目，并最终提高安大略省西北部的矿产资源潜力。