Identification of presolar components in the Solar System's oldest dated solids

• Applicant: Dr. Quinn Shollenberger
• Subject Area: Mineralogy, Petrology and Geochemistry
• Term: from 2020 to 2021
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 440227108

To decipher the events in the early Solar System that eventually lead to the formation of Earth, we must understand the formation of the earliest solid materials, which are calcium-aluminum-rich inclusions (CAIs). CAIs are contained within primitive meteorites and they can be used to study the formation and evolution of the earliest phase of Solar System development. CAIs formed about 4.567 billion years ago near the young sun within a relatively short amount of time (<50,000 years) before they were transported distally to the bulk meteorite forming regions. As such, understanding the formation and evolution of CAIs is imperative to assess the mixing and transport processes that occurred in the early Solar System. Specifically, measuring the isotopic compositions of CAIs allows researchers to understand the nature of the building blocks during that phase of the Solar System’s history. Therefore, CAIs are the focus of this fellowship application, and I will use them specifically to better understand:1) How/if supernova and/or multiple nucleosynthetic sources contributed material to the early Solar System2) Presolar carriers of specific elements in the region where CAIs formed3) How CAIs and later-formed Solar System materials (e.g., Earth) are relatedUnlike previous studies that have examined bulk CAIs, which represent an average CAI composition, in the proposed work, the first of its kind, I will identify the building blocks of the individual components contained within CAIs. This will be done utilizing a well-established sequential acid leaching technique, which has been used previously to identify individual components within bulk meteorites. Acid leaching will be performed on multiple CAIs and the isotopic composition of multiple elements (Mg, Si, Fe, Ti, Hf) will be measured on the leachate fractions. Also, a portion of each leachate fraction from one CAI will be analyzed under a scanning electron microscope to characterize the individual parts and interpret the isotopic results. If correlations exist for the isotopic compositions of the elements, this would mean these elements are hosted in the same presolar carrier and are derived from the same stellar source, such as a supernova. Conversely, if no correlations are observed, this informs us that the CAI-forming region was well mixed with presolar matter from diverse stellar environments in a short amount of time. Additionally, through the use of Mg, Si, Fe, and Ti isotopes in the leaching fractions, information will also be obtained on the subsequent history of the CAIs such as condensation and evaporation events. This data will be compared with current models for such events occurring in the early Solar System. As such, identifying the components of CAIs and their subsequent history will help us understand the evolution of early formed solid material and will shed new light on the material and events that took place in the earliest epoch of the Solar System.

• DFG Programme: Research Fellowships
• International Connection: USA
• Host: Professor Dr. Edward D. Young