Precambrian Earth Evolution

拟议的研究计划将调查地壳/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因素，计划中的研究将有助于更好地理解一些长期存在的问题：地球最早地壳的性质、海洋和生命的起源时间和方式、现代风格的板块构造是否贯穿地球历史、大陆和大陆根是如何形成的，以及短暂而大量的全球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，记录下非同寻常的灾难性火山事件，这些火山事件戏剧性地塑造了前寒武纪的地球，并为一些加拿大自然资源（如镍、铜、铂族元素）的起源提供见解。将进行的科学研究涉及综合和多学科的方法，包括实地考察、岩石学、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质谱法，通过传统的（热电离质谱法）和原位高空间分辨率（<40微米）的方法（激光烧蚀多收集器电感耦合等离子体质谱法和二次离子体质谱法）来确定高精度的U-Pb日期。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，以阐明其起源。其中一些技术是最近在阿尔伯塔大学开发的，在加拿大是独一无二的。

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.