Towards a process-based understanding of rare-earth element deposits

这项研究涉及一组被称为稀土元素（ree）的17种元素，它们构成了现代社会所依赖的高科技设备的重要组成部分。或许最重要的是，稀土元素是风力涡轮机、电池和光伏电池等新兴绿色技术不可或缺的组成部分；这些技术对解决气候危机至关重要，因为能源部门是人类温室气体排放的最大单一来源。我们对电子产品的依赖和可再生能源的发展推动了稀土需求的快速增长。然而，全球稀土产量仅限于相对较少的稀土矿床，其中90%源自中国。因此，对应对稀土需求增加的能力和获取这些重要资源的安全性都存在重大关切。因此，寻找新的、多样化的稀土元素来源对于维持我们的生活方式和促进我们向低碳未来过渡至关重要。稀土元素最重要的来源是“碳酸岩”和“碱性”火成岩。这些岩石在地球深处以岩浆的形式形成，然后在较浅的深处上升和凝固，集中稀土元素，最终暴露在地球表面。然而，导致它们在稀土元素中富集的确切形成过程尚不清楚，而且它们在地表上的小尺寸使得它们极难被发现。该项目将增加我们对这些岩石的了解，并开发一种新的工具，使用三步法有效地定位与这些岩石类型相关的未来稀土矿床。我的研究项目的第一步将开发一个计算工具来模拟碳酸盐岩和碱性火成岩的形成。这个工具可以用来提高我们对地球上这些含稀土的火成岩的理解，并预测它们的分布。我研究的第二步将通过分析其形成在周围地质上留下的特征“模式”，为定位稀土矿床奠定基础。当碳酸盐岩和碱性岩石在较浅的深度固化时，它们会改变周围的“乡村岩石”，形成被称为“泥质岩”的蚀变带。这些生物具有复杂的结构和结构，目前还没有得到很好的理解。通过对微晶岩的深入了解，我们可以将其作为难以捉摸的稀土矿床的“路标”，因为微晶岩带比产生它们的含稀土的火成岩更大，更容易找到。为了做到这一点，我将对表现出不同结构和纹理的两个著名的fenite区域进行详细研究。通过将结构和化学观察与我的计算模型相结合，我将对它们的形成和REE富集建立一个全面的了解。这种对含稀土火成岩就位和矿物形成的新认识将使我的项目进入最后阶段：开发利用遥感（航空）技术寻找稀土矿床的新方法。这些技术，我将与工业伙伴一起开发，将寻找有限带，作为与之相关的稀土矿床的标志。这种方法可能特别有利于在迄今尚未勘探但正在出现的前沿地区（如北极和东非）寻找稀土矿床。

This research relates to a set of 17 elements called the rare-earth elements (REEs), which form an essential component of the high-tech devices on which modern society depends. Perhaps most importantly, REEs are integral to emerging green technologies such as wind turbines, batteries and photovoltaic cells; technologies that will be crucial in addressing the climate crisis, since the energy sector is the largest single contributor to human greenhouse gas emissions. Our reliance on electronics and the development of renewable energy sources is driving rapid increases in the demand for REEs. However, global production is restricted to relatively few REE deposits, with 90% originating in China. Consequently, there are significant concerns over both the capacity to respond to increased REE demand, and the security of access to these vital resources. Finding new and diverse sources of REEs is therefore essential to maintain our way of life and facilitate our transition to a low-carbon future.The most important sources of REEs are within 'carbonatite' and 'alkaline' igneous rocks. These rocks form deep in the Earth as magmas, which then ascend and solidify at shallower depths, concentrating REEs that eventually become exposed on the Earth's surface. However, the exact formation processes that lead to their enrichment in REEs are poorly understood, and their small size on the surface makes them extremely hard to find. This project will increase our understanding of these rocks, and develop a novel tool to efficiently locate future REE deposits associated with these rock types, using a three-step process.The first step in my research project will develop a computational tool to model how carbonatite and alkaline igneous rocks form. This tool can be used to improve our understanding of, and predict the distribution of, these REE-bearing igneous rocks on Earth.The second step of my research will lay the foundations for locating REE deposits, by analysing the characteristic 'patterns' that their formation leaves on the surrounding geology. When carbonatite and alkaline rocks solidify at shallower depths they alter the surrounding 'country rock', creating alteration zones termed 'fenites'. These fenites have complex structures and textures and are not well understood. By developing a robust understanding of fenites, we can use them as 'signposts' for elusive REE deposits, as the fenite zones are larger and easier to find than the REE-bearing igneous rocks that create them. To accomplish this, I will conduct a detailed study of two well-known fenite zones that exhibit varying structures and textures. By combining structural and chemical observations with my computational models, I will build a holistic understanding of their formation and REE enrichment. This new understanding of the emplacement of REE-bearing igneous rocks and the formation of fenites will enable the final stage of my project: developing new ways of finding REE deposits using remote sensing (airborne) techniques. These techniques, which I will develop alongside industrial partners, will search for fenite zones as signposts for the REE deposits that are associated with them. This methodology is likely to be particularly beneficial in locating REE deposits in hitherto poorly explored, but emerging frontiers, such as the Arctic and East Africa.