Precambrian Earth Evolution

前寒武纪地球演化

• 批准号: 170087-2013
• 负责人: Heaman, Larry
• 金额: $ 3.5万
• 依托单位: University of Alberta
• 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=569542
• 关键词: Precambrian; Earth; Evolution

The proposed research program will investigate the origin and evolution of Earth's crust/mantle system, primarily during the Precambrian. There are many uncertainties about Precambrian Earth evolution and the planned research will contribute to a better understanding of long-standing questions about the nature of Earth's earliest crust, when and how oceans and life originated, whether modern-style plate tectonics operated throughout Earth history, how continents and continental roots form, and the impact of short-lived and voluminous episodes of global mafic magmatism on Earth evolution. The planned research will revolutionize our understanding of how continents and the subcontinental lithospheric mantle formed, document unusual catastrophic volcanic events that dramatically shaped the Precambrian Earth, and provide insight into the origin of some Canadian natural resources (e.g., nickel, copper, platinum group elements). The scientific research to be conducted involves an integrated and multi-disciplinary approach involving fieldwork, petrography, geochronology, and in situ isotopic/ geochemical techniques. The planned research will utilize state-of-the-art and cutting-edge mass spectrometry that allow the determination of high-precision U-Pb dates by conventional (thermal ionization mass spectrometry) and in situ high spatial resolution (<40 micron) methods (laser ablation multi-collector inductively coupled plasma mass spectrometry and secondary ion mass spectrometry). In addition, other tracer isotope systems (i.e., Pb, Sr, Hf and O) will be applied to primary magmatic minerals to elucidate their origins. Some of these techniques have been recently developed at the University of Alberta and are unique in Canada.

拟议的研究计划将主要研究前寒武纪期间地壳/地幔系统的起源和演化。前寒武纪地球演化存在许多不确定性，计划中的研究将有助于更好地理解长期存在的问题，例如地球最早地壳的性质、海洋和生命何时以及如何起源、现代板块构造是否在整个地球历史中运作、大陆和大陆根是如何形成的，以及全球镁铁质岩浆活动的短暂而大量的事件对地球演化的影响。计划中的研究将彻底改变我们对大陆和次大陆岩石圈地幔如何形成的理解，记录戏剧性地塑造了前寒武纪地球的不寻常的灾难性火山事件，并深入了解一些加拿大自然资源（例如镍、铜、铂族元素）的起源。 ）。 将进行的科学研究涉及综合和多学科方法，涉及实地考察、岩相学、地质年代学和原位同位素/地球化学技术。计划中的研究将利用最先进的尖端质谱技术，通过传统（热电离质谱）和原位高空间分辨率（<40微米）方法测定高精度U-Pb日期（激光烧蚀多接收器电感耦合等离子体质谱法和二次离子质谱法）。此外，其他示踪同位素系统（即 Pb、Sr、Hf 和 O）将应用于原生岩浆矿物，以阐明其来源。其中一些技术是阿尔伯塔大学最近开发的，在加拿大是独一无二的。