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

前寒武纪地盾构成了加拿大地壳的重要组成部分，许多太古宙（>25亿年）的组成部分在大约18亿年前的一次灾难性碰撞中连接在一起，称为跨哈德逊造山运动，该运动保存在从萨斯喀彻温省延伸到巴芬岛的线性带中。这次碰撞与岩石圈板块的运动有关，形成了一座山脉，其规模可能与今天的喜马拉雅山相当。在碰撞之前，不同地壳元素之间存在复杂的相互作用，产生了岩浆、沉积物和结构。这项研究的部分内容包括由多名研究生和本科生在现场进行测绘和采样，以及应用现代分析技术进行微量元素和同位素分析，旨在揭示 18 亿年前重大碰撞之前不同地壳块之间的相互作用，重点关注萨斯喀彻温省北部和曼尼托巴省暴露良好的岩石。有必要定义地壳和地幔不同部分的组成，以便了解它们如何相互作用。此外，加拿大中部的前寒武纪岩石蕴藏着世界级的铜、锌、金、铀和稀土元素热液矿床，它们的形成与造山带的演化密切相关。****这项研究将集中于这次造山事件期间形成的最年轻的火成岩（大约1.85至18.2亿岁），部分原因是这代表了该事件中最复杂的部分，并将提供该造山带的化学和同位素“指纹”可能参与这些岩石形成的地壳和地幔部分。此外，大陆碰撞时在盆地中形成的沉积岩保存了作为碎屑矿物的锆石，它们记录了这些沉积物源区的年龄和特征。随后，山脉被侵蚀，沉积物沉积在富含铀的阿萨巴斯卡盆地，该盆地下方有一个蚀变带，可能代表了古老的风化剖面。将对其进行检查以确定其来源，以及这是否可能是较年轻矿床的金属（包括铀）的重要来源。所有这些工作的直接成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、政府或加拿大矿产行业工作。***

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.***