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

点击翻译按钮获取中文摘要

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.