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。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，如地球最早地壳的性质、海洋和生命起源的时间和方式、现代式板块构造是否在整个地球历史上运作、大陆和大陆根是如何形成的，以及全球短暂而大规模的镁铁质岩浆活动对地球演化的影响。这项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形成方式的理解，记录下戏剧性地塑造前寒武纪地球的不同寻常的灾难性火山事件，并为加拿大一些自然资源(如镍、铜、铂族元素)的起源提供洞察。将进行的科学研究涉及综合和多学科方法，涉及实地工作、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和尖端的质谱学，允许用传统的(热电离质谱)和现场高空间分辨率(&lt；40微米)方法(激光烧蚀多收集器电感耦合等离子体质谱和二次离子质谱仪)确定高精度的U-Pb数据。此外，其他示踪同位素系统(即铅、锶、氢和氧)也将应用于原生岩浆矿物，以阐明其成因。其中一些技术是艾伯塔大学最近开发的，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.