Mechanics and Applications of Titanium Isotope Fractionation in Terrestrial Magmas

陆相岩浆中钛同位素分馏的机理及应用

• 批准号: 2028532
• 金额: --
• 依托单位: CARDIFF UNIVERSITY
• 依托单位国家: 英国
• 项目类别: Studentship
• 财政年份: 2018
• 资助国家: 英国
• 起止时间: 2018 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=studentship-2028532
• 关键词: Mechanics; Applications; Titanium; Isotope; Fractionation

Magmas erupted at the surface of the Earth and Moon offer a wide array of opportunities to study the compositional heterogeneity and dynamics of the terrestrial and lunar mantles, as well as magma evolution in crustal magma reservoirs. However, classical geochemical tools often give incomplete or ambiguous answers to important questions such as: what minerals are involved during partial melting and magma evolution? What is the water content of the mantle source and resulting magma? Can the tectonic setting of past volcanism be inferred from magma compositions?The aim of this PhD project is to use the novel titanium stable isotope system to provide answers to these questions. Amongst the flurry of chemical elements available for isotopic study, titanium has the unique ability to be able to solely trace the involvement of oxide minerals in magma genesis and evolution[1]. The student will perform ultra-high precision Ti stable isotope measurements[2] of magmatic rocks and their minerals to study a range of questions related to the generation and evolution of terrestrial and lunar magmas. Analytical work will be carried out in the newly set up state-of-the-art isotope geochemistry laboratory at Cardiff University. In addition, the student will use the recently installed FEG-SEM (Field Emission Gun - Scanning Electron Microscope) facility at Cardiff University to determine the budget of Ti in selected samples. This system is designed to enable rapid mapping of mineral compositions at high spatial resolution over large areas.The combined dataset will allow the student to attain the following research objectives:1. Determine Ti isotope partitioning effects during partial melting and magma differentiation.2. Measure the Ti stable isotope composition of a range of lunar samples in order to model the evolution of the lunar magma ocean.3. Evaluate the effects of melt water content and oxygen fugacity on the behaviour of Ti isotope during magma differentiation.4. Determine the Ti stable isotope composition of a range of terrestrial lavas and, in doing so, their water content and the tectonic context in which they were emplaced. Overall, this project will allow for a much clearer understanding of magma generation and evolution on the Earth and Moon. References:[1] Millet M-A et al. (submitted to EPSL) Titanium stable isotope investigation of magmatic processes on the Earth and Moon[2] Millet M-A and Dauphas N. (2014) Ultra-precise titanium stable isotope measurements by double-spike high resolution MC-ICP-MS J. Anal. At. Spectrom., 2014, 1444-1458

岩浆在地球和月球的表面爆发提供了各种各样的机会，可以研究陆地和月球披风的组成异质性和动力学，以及地壳岩浆储层中的岩浆演化。但是，经典的地球化学工具通常会对重要问题提供不完整或模棱两可的答案，例如：部分熔化和岩浆演变中涉及哪些矿物质？地幔源和由此产生的岩浆的水含量是什么？可以从岩浆成分中推断出过去火山的构造环境吗？该博士学位项目的目的是使用新颖的钛稳定同位素系统为这些问题提供答案。在用于同位素研究的一系列化学元素中，钛具有独特的能力，能够仅追踪氧化物矿物在岩浆起源和进化中的参与[1]。 该学生将执行超高精度TI稳定的同位素测量[2]的岩浆岩石及其矿物质，以研究与陆地和月球岩浆的产生和演变有关的一系列问题。分析工作将在加的夫大学的新建同位素地球化学实验室中进行。此外，学生还将使用最近安装的FEG -SEM（现场发射枪 - 扫描电子显微镜）设施在加的夫大学确定选定样品中TI的预算。该系统旨在以高空间分辨率在大面积的高空间分辨率下快速映射矿物质。该组合数据集将使学生能够实现以下研究目标：1。在部分熔化和岩浆分化过程中确定Ti同位素分配效果2。测量一系列月球样品的Ti稳定同位素组成，以模拟月球岩浆海洋的演变3。评估熔体水含量和氧散性对岩浆分化过程中Ti同位素行为的影响。4。确定一系列陆地熔岩的Ti稳定同位素组成，并在其中进行水含量和构造环境。 总体而言，该项目将使人们对地球和月球上的岩浆产生和进化有更清晰的了解。参考文献：[1] Millet M-A等。 （提交给EPSL）钛稳定的同位素研究地球和月球上的岩浆过程[2] Millet M-A和Dauphas N.（2014）通过双尖峰高分辨率高分辨率MC-ICP-MS J. Anal。在。 Spectrom。，2014，1444-1458