"Magmatism, metallogeny and tectonics of the Paleoproterozoic core of Canada"

“加拿大古元古代核心的岩浆作用、成矿和构造”

• 批准号: 155085-2012
• 负责人: Ansdell, Kevin
• 金额: $ 1.97万
• 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: 2015
• 资助国家: 加拿大
• 起止时间: 2015-01-01 至 2016-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=569413
• 关键词: Magmatism; metallogeny; tectonics; Paleoproterozoic; core

The Earth's continental crust consists of fragments of ancient igneous and sedimentary rocks that record a complex geological history of crustal growth and reworking over the last 4 billion years. 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 prior to the major collision 1.8 billion years ago. It will be necessary to define the composition of different parts of the crust and mantle in order to understand how they interacted. The research project will focus on the latest igneous rocks that formed during this mountain-building event in the vicinity of Flin Flon (MB) and the Seabee gold mine in northern Saskatchewan, 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, students will be involved with geological mapping projects with the Saskatchewan and Nunavut geosciences surveys to unravel the relationships in a poorly understood part of Saskatchewan, and the Hall Peninsula on Baffin Island, which has not been mapped for 40 years. Direct outcomes of all this work will be student theses and journal papers, and well-trained new geoscientists to work in the Canadian minerals industry.

地球的大陆地壳由古老的火成岩和沉积岩的碎片组成，它们记录了过去40亿年来地壳生长和改造的复杂地质历史。前寒武纪地盾构成了加拿大地壳的重要部分，许多太古代（> 25亿年）的组成部分在大约18亿年前的一次灾难性碰撞中结合在一起，称为跨哈德逊造山带，该造山带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，形成了一个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发生了复杂的相互作用，产生了岩浆、沉积物和构造。这项研究的一部分，包括一些研究生和本科生在实地进行绘图和取样，以及应用现代分析技术分析微量元素和同位素，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。有必要确定地壳和地幔不同部分的组成，以便了解它们如何相互作用。 该研究项目将侧重于最新的火成岩，形成在这个造山活动在附近的弗林弗隆（MB）和锡比金矿在北方萨斯喀彻温省，部分原因是因为这代表了最复杂的部分，这一事件，并将提供一个化学和同位素的“指纹”的地壳和地幔的部分，可能参与了这些岩石的形成。此外，学生将参与萨斯喀彻温省和努纳武特地球科学调查的地质测绘项目，以解开萨斯喀彻温省一个鲜为人知的部分的关系，以及巴芬岛上的霍尔半岛，40年来一直没有被绘制。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加拿大矿业工作。