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

• Applicant: Dr. Samuel Ebert
• Subject Area: Mineralogy, Petrology and Geochemistry
• Term: from 2018 to 2020
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 413893359

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.

• DFG Programme: Research Fellowships
• International Connection: USA
• Host: Professor Dr. Alexander N. Krot