Project Title: High spatial resolution 26Al-26Mg dating of Wark-Lovering rims around refractory inclusions in primitive meteorites. Summary: The primary objective of this research proposal is to quantify the timescales of formations of the rim sequence around refractory inclusions. Calcium aluminum rich inclusions (CAIs) in primitive meteorites represent first formed solids from the early solar nebula. The rim sequences around them represent a very unique yet ubiquitous event in the early Solar system. These rim sequences are mono or bi-mineralic in nature and they are universally present in all types of CAIs in all primitive meteorites. Yet their composition and mineralogy does not match with CAIs or matrix of the meteorite, ruling out the possibility of their origin due to reaction between the core of CAIs and matrix of the meteorites. They are also mysteriously absent around chondrules which have suggested to be formed less that ~2my after CAIs formation. Therefore the formation of these rim sequences marks an important universal and yet abrupt event in the early Solar system. Their origin suggests deposition during different absolute time after ceasing the growth of CAIs. An alternate hypothesis suggests existence of a cosmic conveyor belt, which carried these CAIs from CAIs formation region to rim formation region. In both cases, abrupt yet consistent mineralogy of the rim sequence suggests rapid changes in the solar nebula. This project proposes to perform dating of these rims using Al-Mg short-lived chronometer using high spatial resolution NanoSIMS (Secondary Ionization Mass Spectrometry) at Arizona State University to establish chronology of these rim sequences. The results from this study hope to put constraints on changes in chemical and physical conditions in the early solar nebula. This project will provide significant insight into the formation and evolution of the early Solar System and addresses the following science questions: How did the Suns family of planets and minor bodies originate? and How did the Solar System evolve to its current diverse state?
|Effective start/end date||9/1/13 → 8/31/16|
- NASA: Goddard Space Flight Center: $89,385.00