Investigation of O-isotopes in Na-Al-rich chondrules and Ca,Al-rich inclusions from ordinary chondrites

富Na-Al球粒和普通球粒陨石中富Ca、Al包裹体中O-同位素的研究

• 批准号: 413893359
• 负责人: Dr. Samuel Ebert
• 金额: --
• 依托单位: School of Ocean and Earth Sciences and Technology
• 依托单位国家: 德国
• 项目类别: Research Fellowships
• 财政年份: 2018
• 资助国家: 德国
• 起止时间: 2017-12-31 至 2019-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/413893359?language=en
• 关键词: Investigation; isotopes; Na; Al; rich

In order to understand why our solar system looks the way it does today, we need to decipher the processes that have shaped its components since their formation ~4,567 million years ago. Meteorites are essential for studying these processes, as they carry the cosmological information and history of the first particles that emerged before matter started coalescing into larger planetary bodies. Consequently, studying not only bulk meteorites but also their individual components is an excellent way to gain information about the evolution of our young solar system.Chondritic meteorites consist of different components such as chondrules (melt droplets that chondritic meteorites are named after) and so-called refractory inclusions such as Ca,Al-rich inclusions. These Ca,Al-rich inclusions are considered to be the oldest identified particles and mark the beginning of our solar system ~4,567 million years ago, and they may represent a precursor material for the above-mentioned chondrules. The previous model of how Ca,Al-rich inclusions formed states that they formed in a very short time (<20k years) near the young sun and were then unevenly distributed throughout the solar disk.In his doctoral thesis, the applicant revealed, through studying a type of chondrule called Na-Al-rich chondrules, that in addition to Ca,Al-rich inclusions, an unknown type of refractory material may exist as a precursor for chondrules. This unknown refractory material is similar in mineralogy to Ca,Al-rich inclusions but differs in its composition of Ti-isotopes. As a result, refractory components (Ca,Al-rich inclusions and this unknown material) must have formed in at least two isotopically different regions; this implication challenges the current model of a single formation region for refractory materials.The aim of this project is to clarify where exactly these regions were situated by investigating, for the first time, the O-isotopes in the rare group of Na-Al-rich chondrules in ordinary chondrites. Since each region in the early solar system has its own O-isotopic fingerprint, this will allow us to draw conclusions about where this unknown refractory chondrule precursor material formed.This project will also help us determine whether Na-Al-rich chondrules actually formed in the ordinary chondrite region itself or were transported to this region before accretion, as it thought to have happened for Ca,Al-rich inclusions. In general, studying the formation and distribution of the earliest particles in our solar system is of significant interdisciplinary interest, and this project will thus be important for e.g. model the evolution of our young solar system.

为了理解为什么我们的太阳系看起来像今天这样，我们需要破译自45.67亿年前形成以来塑造其组成部分的过程。陨石对于研究这些过程至关重要，因为它们携带着宇宙学信息和物质开始合并成更大行星体之前出现的第一批粒子的历史。因此，不仅研究大块陨石，而且研究它们的单个成分是获得年轻太阳系演化信息的一个很好的方法。球粒陨石由不同的成分组成，如球粒（陨石的命名来源于熔融液滴）和所谓的耐火包裹体，如富含Ca，Al的包裹体。这些富含Ca，Al的包裹体被认为是最古老的已识别粒子，标志着我们太阳系的开始~ 45.67亿年前，它们可能代表上述球粒的前体材料。以前关于富Ca、Al夹杂物形成的模型认为它们在很短的时间内形成在其博士论文中，申请人通过研究一种称为富钠铝球粒的球粒，发现除了Ca，富铝包裹体，可能存在一种未知类型的耐火材料作为球粒的前体。这种未知的耐火材料在矿物学上与富Ca、Al包裹体相似，但其Ti同位素组成不同。因此，耐火部件（富含Ca、Al的包裹体和这种未知物质）必须形成于至少两个同位素不同的区域;这一暗示挑战了目前耐火材料单一形成区域的模型。2本项目的目的是通过调查，首次，普通陨石中罕见的富钠铝球粒中的O同位素。由于早期太阳系的每个区域都有自己的O同位素指纹，这将使我们能够得出关于这种未知的耐火球粒前体物质形成的结论。该项目还将帮助我们确定富含Na-Al的球粒是否实际上是在普通球粒区域本身形成的，或者在吸积之前被运送到这个区域，因为它认为发生了富含Ca，Al的夹杂物。总的来说，研究太阳系中最早粒子的形成和分布具有重要的跨学科意义，因此该项目对于模拟我们年轻太阳系的演化非常重要。