Magmatism, sedimentation and the uranium mineral system in the Paleoproterozoic core of Canada

加拿大古元古代核心的岩浆作用、沉积作用和铀矿物系统

• 批准号: RGPIN-2017-04427
• 负责人: Ansdell, Kevin
• 金额: $ 2.84万
• 依托单位: University of Saskatchewan
• 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=711035
• 关键词: Magmatism; sedimentation; uranium; mineral; system

The Precambrian Shield makes up a significant portion of the crust in Canada, and many of the Archean (>2.5 billion years old) components were joined together about 1.8 billion years ago during a cataclysmic collision, called the Trans-Hudson orogeny, that is preserved in a linear belt that extends from Saskatchewan to Baffin Island. The collision, which was related to the motion of lithospheric plates, formed a mountain range that was probably of the same scale as the present-day Himalayas. In the lead up to the collision, there were complex interactions between different crustal elements which generated magmas, sediments, and structures. The aim of part of this research, which involves mapping and sampling in the field by a number of graduate and undergraduate students, and the application of modern analytical techniques for the analysis of trace elements and isotopes is to unravel the interaction between different crustal blocks just prior to the major collision 1.8 billion years ago, with a focus on the well-exposed rocks in northern Saskatchewan and Manitoba. It will be necessary to define the composition of different parts of the crust and mantle in order to understand how they interacted. In addition the Precambrian rocks in central Canada host world-class hydrothermal deposits of copper, zinc, gold, uranium, and rare earth elements, and their formation is intimately related to the evolution of the mountain belt. The research will focus on the youngest igneous rocks (about 1.85 to 1.82 billion years old) that formed during this mountain-building event, partly because this represents the most complex part of this event, and will provide a chemical and isotopic “fingerprint” of the parts of the crust and mantle that might have been involved in the formation of these rocks. In addition, the sedimentary rocks that formed in basins as continental collisions were occurring preserve zircons as detrital minerals, and they record the age and character of the source regions for these sediments. The mountain belt was then eroded, and sediments were deposited in the uranium-rich Athabasca Basin, under which is a zone of alteration that may represent an ancient weathered profile. This will be examined to determine its origin, and whether this might be an important source of metals, including uranium, for the younger mineral deposits. Direct outcomes of all this work will be student theses and journal papers, and well-trained new geoscientists to work in academia, government or the Canadian minerals industry.

前寒武纪构成了加拿大地壳的很大一部分，大约18亿年前，在灾难性的碰撞中，许多大将（> 25亿年历史）的组件被合并在一起，称为Trans-Hudson造口，被保存在从萨斯喀彻温省到Baffin群岛的线性腰带。与岩石圈板的运动有关的碰撞形成了一个可能与当今喜马拉雅山脉相同的山脉。在发生碰撞之前，产生岩浆，沉积物和结构的不同地壳元素之间存在复杂的相互作用。这项研究的一部分的目的是涉及许多毕业生和本科生在现场进行映射和取样，以及现代分析技术在痕量元素和同位素的分析中的应用是在18亿年前的主要冲突之前揭开不同的地壳块之间的相互作用，重点是在北方sasksath和andernnernnernnernnernnernnernnern的岩石上进行。为了了解它们的相互作用方式，有必要定义地壳和地幔不同部分的组成。此外，加拿大中部的前寒冷岩石是铜，锌，金，铀和稀土元素的世界一流的氢气沉积物，它们的形成与山带的演变密切相关。 该研究将集中于在这次山区建设活动中形成的最年轻的火成岩（约1.85至18.2亿年的历史），部分原因是这代表了本次活动的最复杂部分，并将提供化学和同位素的“指纹”，这些岩石和壁炉的各个部分可能涉及这些岩石的形成。此外，作为连续碰撞的贝司形成的沉积岩正在保存锆石作为碎屑矿物，并记录了这些沉积物的源区域的年龄和特征。然后发出山带，并将沉积物沉积在铀丰富的阿萨巴斯卡盆地，在下面是一个变化的区域，可能代表古老的风化概况。这将进行检查以确定其起源，以及这是否可能是包括铀在内的年轻矿藏的重要来源。所有这些工作的直接结果将是学生论文和期刊论文，以及训练有素的新地球科学家，在学术界，政府或加拿大矿业行业工作。