¹Jan Leitner, ²Christian Vollmer, ³Christine Floss, ⁴Jutta Zipfel, ¹Peter Hoppe
¹Max Planck Institute for Chemistry, Particle Chemistry Department, Hahn-Meitner-Weg 1, 55128 Mainz, Germany
²Institute for Mineralogy, Westfälische Wilhelms-Universität, Correnstrasse 24, 48149 Münster, Germany
³Laboratory for Space Sciences and Physics Department, Washington University, One Brookings Drive, St. Louis, MO 63130, USA
⁴Forschungsinstitut und Naturmuseum Senckenberg, Sektion Meteoritenforschung, Senckenberganlage 25, 60325 Frankfurt, Germany

Carbonaceous chondrites are fragments from primitive parent asteroids, which represent some of the most primitive meteorites accessible for laboratory analysis and offer therefore the best opportunity to explore the chemical and physical conditions in the early Solar System. Here, we report the identification of presolar grains, which are circumstellar condensates that date back from before the formation of our Solar System, in fine-grained dust rims around chondrules in carbonaceous chondrites. Average presolar grain abundances in the rims of aqueously altered chondrites (petrologic type 2) are three times higher than in the respective interchondrule matrices, while for the most pristine specimens (petrologic type 3), the opposite is observed. The presence of these grains implies a nebular origin of the rim material, and gives evidence for differing alteration pathways for different reservoirs of fine-grained material found in primitive meteorites. Moreover, our findings indicate formation of the fine-grained rims in the solar nebula prior to parent-body accretion, giving support to accretionary scenarios for parent-bodies in the presence of dust-rimmed chondrules.

Reference
Leitner J, Vollmer C, Floss C, Zipfel J, Peter Hoppe (2015) Ancient stardust in fine-grained chondrule dust rims from carbonaceous chondrites. Earth and Planetary Science Letters (in Press)
Link to Article [doi:10.1016/j.epsl.2015.11.028]

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