Thermochemical stability of low-iron, manganese-enriched olivine in astrophysical environments
Abstract
Low-iron, manganese-enriched (LIME) olivine grains are found in cometary samples returned by the Stardust mission from comet 81P/Wild 2. Similar grains are found in primitive meteoritic clasts and unequilibrated meteorite matrix. LIME olivine is thermodynamically stable in a vapor of solar composition at high temperature at total pressures of a millibar to a microbar, but enrichment of solar composition vapor in a dust of chondritic composition causes the FeO/MnO ratio of olivine to increase. The compositions of LIME olivines in primitive materials indicate oxygen fugacities close to those of a very reducing vapor of solar composition. The compositional zoning of LIME olivines in amoeboid olivine aggregates is consistent with equilibration with nebular vapor in the stability field of olivine, without re-equilibration at lower temperatures. A similar history is likely for LIME olivines found in comet samples and in interplanetary dust particles. LIME olivine is not likely to persist in nebular conditions in which silicate liquids are stable.
Additional Information
© 2012 The Meteoritical Society. Received 07 June 2011; revision accepted 10 February 2012. The authors thank two anonymous reviewers. This work was supported by NASA-COSNNX10AI42G (DSE), NASA-COS-NNG09AG94G (MKW), NASA-DDAP-NNX08AG23G (MKW), and NASA-COS-NNX09AG40G (E. Stolper, PI). This research has made use of NASA's Astrophysics Data System. Editorial Handling––Dr. John BradleyAttached Files
Published - Ebel2012p18167Meteorit_Planet_Sci.pdf
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Additional details
- Eprint ID
- 31621
- Resolver ID
- CaltechAUTHORS:20120523-161355390
- NNX10AI42G
- NASA COS
- NNG09AG94G
- NASA COS
- NNX08AG23G
- NASA DDAP
- NNX09AG40G
- NASA COS
- Created
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2012-05-24Created from EPrint's datestamp field
- Updated
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2021-11-09Created from EPrint's last_modified field