¹Birgit Schulz, ¹Christian Vollmer, ²Peter Hoppe, ^2,3Jan Leitner, ⁴Lindsay P. Keller
Meteoritics & Planetary Science, (in Press), 1–15
Open Source Link to Article [DOI: 10.1111/maps.70257]

¹Institut für Mineralogie, Universität Münster, Münster, Germany
²Max-Planck-Institut für Chemie, Mainz, Germany
³Institut für Geowissenschaften, Ruprecht-Karls-Universität Heidelberg, Heidelberg, Germany
⁴XI3, Astromaterials Research and Exploration Science (ARES) Division, NASA Johnson Space Center, Houston, Texas, USA
Published by arrangement with John Wiley & Sons

Eight anhydrous interplanetary dust particles (IDPs) were analyzed for their oxygenisotopic compositions and mineralogy. They show oxygen isotopic compositions from 16O-rich to16O-poor, due to mixing of different reservoirs inherited from the protosolar molecular cloud andthe early solar nebula. Glass with embedded metal and sulfide (GEMS) in anhydrous IDPsrecord a variety of formation environments in which they adopted oxygen isotopic compositionof surrounding gas, because amorphous silicates exchange isotopes with gaseous species moreeffectively than crystalline materials due to their open framework. Equilibrated aggregates (EAs)form from GEMS via secondary processes that involve recrystallization and have similarchemical and isotopic heterogeneity as GEMS. A common feature of most anhydrous IDPs is aslight enrichment either in 17O or, rarer, in 18O relative to a slope-1 line on which primitivemeteorites and their components plot. Possible explanations might be organic matter enriched inheavy oxygen. Although some of the investigated IDPs show hints of atmospheric entry heating,oxygen isotopic compositions of the IDPs are not shifted toward the terrestrial fractionation line(TFL), as seen for larger micrometeorites and cosmic spherules. Thus, we conclude thatanhydrous IDPs preserve primordial oxygen isotopic compositions of early solar systemreservoirs.