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很大一部分，大约18亿年前，太古宙(&gt；25亿年前)的许多成分在一场称为跨哈德逊造山的灾难性碰撞中拼接在一起，该碰撞被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，形成了一条可能与今天的喜马拉雅山脉规模相同的山脉。在碰撞之前，不同的地壳元素之间存在着复杂的相互作用，形成了岩浆、沉积物和构造。这项研究的一部分--包括由一些研究生和本科生进行实地测绘和取样，以及应用现代分析技术进行微量元素和同位素分析--的目的是揭示18亿年前大碰撞之前不同地壳块体之间的相互作用，重点是萨斯喀彻温省北部和马尼托巴省裸露程度很高的岩石。有必要确定地壳和地幔不同部分的组成，以了解它们是如何相互作用的。此外，加拿大中部的前寒武纪岩石拥有世界级的热液矿床，包括铜、锌、金、铀和稀土元素，它们的形成与山带的演化密切相关。*研究将集中在这次造山事件中形成的最年轻的火成岩(大约18.5亿到18.2亿年前)，部分原因是这是这次造山事件中最复杂的部分，并将提供可能参与这些岩石形成的地壳和地幔部分的化学和同位素指纹。此外，大陆碰撞时盆地中形成的沉积岩以碎屑矿物的形式保存着锆石，它们记录了这些沉积物的源区的年龄和特征。山带随后遭到侵蚀，在富含铀的阿萨巴斯卡盆地沉积了沉积物，盆地下方是一条可能代表古老风化剖面的蚀变带。将对其进行研究，以确定其来源，以及这是否可能是年轻矿藏的重要金属来源，包括铀。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.***