The origin of Earth's volatiles - new constraints from isotopic analyses of meteorites

关于地球吸积的一个关键问题是，导致地球预算不稳定的积木的来源。因为生命的出现需要挥发物，所以这个问题很重要，因为这个问题指导我们对宜居行星是如何形成的基本理解。特别是，地球的挥发物是来自太阳系内部的物质，还是由小行星提供的，这些小行星的轨道来自更易挥发的外太阳系？为了获得有关地球挥发性物质来源的新限制，该PHD项目对陨石进行了分析，以确定各种陨石类型和陨石成分(如CaI和球粒陨石)以及陆地岩石中挥发性元素(包括锌、镉和碲)的质量依赖和质量无关的同位素组成的变化。来自月球和火星的样本也被安排进行分析，以调查这些天体的挥发性来源。为了实现这一目标，该项目在伦敦帝国理工学院地球科学与工程系的MAGIC实验室进行了大量的动手分析研究。这包括在洁净室设施中进行样品准备，以及使用我们的三个同位素比质谱仪之一进行高精度的同位素分析。

A key question of Earth's accretion is origin of the building blocks that contributed to Earth's volatile budget. As volatiles are needed for the emergence of life, the question is important as this guides our basic understanding of how habitable planets are formed. In particular, were Earth's volatiles sourced from inner Solar System materials or were they provided by asteroids with 'stray' orbits that originated from the more volatile-rich outer Solar System? To obtain new constraints on the origin of Earth's volatile inventory, this PhD project encompasses analyses of meteorites to determine variations in both mass-dependent and mass-independent isotope compositions of volatile elements, including zinc, cadmium, and tellurium, for various meteorite types and meteorite constituents (such as CAI's and chondrules), as well as terrestrial rocks. Samples from the Moon and Mars are also slated for analysis, to investigate the volatile sources for these bodies. To address this goal, the project involves significant hands-on analytical research in the MAGIC Laboratories at the Department of Earth Science & Engineering of Imperial College London. This includes sample preparation in the clean room facilities and high-precision isotope analyses with one of our three isotope ratio mass spectrometers.