Precambrian Earth Evolution

前寒武纪地球演化

• 批准号: 170087-2013
• 负责人: Heaman, LarryM
• 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: 2017
• 资助国家: 加拿大
• 起止时间: 2017-01-01 至 2018-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=634012
• 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.

拟议的研究计划将调查地球的地壳/地幔系统的起源和演化，主要是在前寒武纪。关于前寒武纪地球演化有许多不确定性，计划中的研究将有助于更好地了解有关地球最早地壳性质的长期问题，海洋和生命何时以及如何起源，现代风格的板块构造是否在整个地球历史中运作，大陆和大陆根如何形成，以及短暂而大量的全球镁铁质岩浆活动对地球演化的影响。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，记录戏剧性地塑造前寒武纪地球的不寻常的灾难性火山事件，并深入了解加拿大一些自然资源的起源（例如，镍、铜、铂族元素）。进行的科学研究涉及综合和多学科的方法，包括野外工作、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和最先进的质谱法，通过常规（热电离质谱法）和现场高空间分辨率（<40微米）方法（激光烧蚀多收集器电感耦合等离子体质谱法和二次离子质谱法）确定高精度铀-铅年代。此外，其它示踪同位素系统（即，Pb、Sr、Hf和O）对原生岩浆矿物的成因进行了探讨。其中一些技术最近在阿尔伯塔大学开发，在加拿大是独一无二的。