Formation and impact histories of the Solar System and planets from chemical and isotopic investigations of planetary materials

我的研究计划的长期范围是了解太阳系的起源，以及行星是如何随着时间的推移形成和演化的。在这些关键过程中，我特别感兴趣的是了解恒星元素的来源对太阳系的贡献，破译行星形成和演化的时间尺度和化学储存库，以及导致受辐射或受冲击的行星材料发生化学和同位素变化的机制。这种宇宙指纹将使我们能够建立模型，以确定类地行星的构成要素，并塑造它们早期演化的情景。我研究的另一个重要主题是了解撞击行星表面的后果，如小行星、月球、火星和地球的撞击。为了实现这些目标，我将研究陨石等地外物质，从阿波罗太空任务中带回的样品，以及选定的陆地撞击坑中的岩石和相关矿藏。 我的计划中计划的三个研究主题及其主要目标包括： 1.太阳系和行星的起源：利用高精度质谱仪，我们可以探测行星材料中元素的相对原子丰度的变化。重要的是要了解太阳系中同位素不均一性的来源，追踪构成分子云的元素的核来源，了解它们并入太阳星云的方式和时间，以及它们在整个原行星盘中的分布。这一主题的另一个重要方面是监测影响行星物质同位素组成的宇宙射线的质量分馏和辐射效应以及随后的解释。 2.行星形成的年代学和储存库：我们可以利用原始行星物质中的高分辨率U-Pb放射性同位素测年系统，破译内太阳系中凝聚(从气体到第一固体)、吸积(行星如何生长)和分化(如何演化)等行星过程的高分辨率年代学。陨石是来自原行星盘不同位置的样品，暴露出不同的化学条件。特别是，还原物质的Sm-ND和Lu-Hf组分将为理解行星形成的过程和储集层提供新的线索。 3.太阳系的撞击：有广泛的证据表明，行星撞击在类地行星、小行星和太阳系卫星的表面留下了伤痕。在寻找地外生命和新的矿化过程中，重要的是确定所输送物质的来源和数量、撞击如何影响行星表面、了解这些事件的时间分布以及在某些情况下矿藏的产生情况。我们可以开发新的模型来解释内太阳系和外太阳系的物质输送，用更好的比较年代学和跨学科的方法来研究受冲击的行星物质。 回答关于太阳系起源和我们行星系统中生命发展条件的基本问题，对人类了解我们的环境，建造宜居行星的化学和物理条件，以及塑造未来的空间探索具有重大意义。拟议的研究将与西方大学的其他教员合作进行，并与加拿大各地的实验室合作，为在致力于卓越的地球化学研究的最先进设施中培训高素质学生创造一个全面的环境。

The long-term scope of my research program is to understand the origin of the Solar System and how planets formed and evolved throughout time. Among these key processes, I am particularly interested in understanding what stellar sources of elements contributed to the Solar System, deciphering the timescales and chemical reservoirs for planetary formation and evolution, and the mechanisms responsible for chemical and isotopic changes in irradiated or shocked planetary materials. This cosmic fingerprinting will enable us to build models to identify the building blocks of terrestrial planets and shape scenarios for their early evolution. Another important theme of my research is to understand the consequences of impacts on planetary surfaces such as those of asteroids, the Moon, Mars, and Earth. To achieve these goals, I will study extra-terrestrial materials such as meteorites, samples brought back from Apollo space missions, and rocks and associated ore deposits from selected terrestrial impact craters. The three planned research themes in my program and their key objectives include: 1. Origins of the Solar System and planets: with high-precision mass spectrometry, we can detect variations in the relative atomic abundances of elements in planetary materials. It is of major importance to understand the origin of isotopic heterogeneities in the solar System and trace the nuclear sources of elements that contributed to the molecular cloud, understand their mode and timing of incorporation within the solar nebula, and their distribution throughout the protoplanetary disk. Another important aspect of this theme is to monitor the mass-fractionation and irradiation effects by cosmic rays that affect the isotopic compositions of planetary materials and the subsequent interpretation. 2. Chronology and reservoirs of planetary formation: we can decipher a high-resolution chronology of planetary processes such as condensation (from gas to the first solids), accretion (how the planets grew) and differentiation (how they evolve) in the inner Solar System using the high-resolution U-Pb radiogenic isotope dating system in pristine planetary materials. Meteorites are samples from different locations of the protoplanetary disk exposing variable chemical conditions. In particular, Sm-Nd and Lu-Hf compositions of reduced materials will provide new clues for understanding the processes and reservoirs of planetary formation. 3. Impacts in the Solar System: there is widespread evidence of scars left by planetary impacts on the surface of terrestrial planets, asteroids, and Solar System satellites. In the search for extra-terrestrial life, and of new mineralization, it is important to characterize the source and volume of delivered materials, how impact affected planetary surfaces, and understand the distribution through time of these events and the production of ore deposits in some cases. We can develop new models to explain the delivery of materials to the inner and outer Solar System with a better comparative chronology and inter-disciplinary approach of shocked planetary materials. Answering the fundamental questions about the origin of the Solar System and conditions for life to develop in our planetary system is of major interest for humans to understand our environment, the chemical and physical conditions to build habitable planets, and to shape the future of space exploration. The proposed research will be carried out in collaboration with other faculty members at Western and with laboratories across Canada will create a comprehensive environment for training high-qualified students in state-of-the-art facilities dedicated to excellence in geochemical research.