Outgassing of ordinary chondritic material and some of its implications for the chemistry of asteroids, planets, and satellites

By L. Schaefer, B. Fegley, Jr.. 2006

136 citations recorded by the source corpus.

We used chemical equilibrium calculations to model thermal outgassing of ordinary chondritic material as a function of temperature, pressure, and bulk composition and use our results to discuss outgassing on asteroids and the early Earth. The calculations include ∼1000 solids and gases of the elements Al, C, Ca, Cl, Co, Cr, F, Fe, H, K, Mg, Mn, N, Na, Ni, O, P, S, Si, and Ti. The major outgassed volatiles from ordinary chondritic material are CH4, H2, H2O, N2, and NH3 (the latter at conditions where hydrous minerals form). Contrary to widely held assumptions, CO is never the major C-bearing gas during ordinary chondrite metamorphism. The calculated oxygen fugacity (partial pressure) of ordinary chondritic material is close to that of the quartz–fayalite–iron (QFI) buffer. Our results are insensitive to variable total pressure, variable volatile element abundances, and kinetic inhibition of C and N dissolution in Fe metal. Our results predict that Earth's early atmosphere contained CH4, H2, H2O, N2, and NH3; similar to that used in Miller—Urey synthesis of organic compounds.

Subfields: Astronomy and Astrophysics, Geophysics, Mechanics of Materials

View Paper: https://www.semanticscholar.org/paper/0692759178594e431f35206a573fdd85cf7e6d27

How researchers see this paper

The researchers whose trusted networks rank it highest, strongest advocate first. Every researcher gets a different order.

In Astronomy and Astrophysics

1. J. Kasting
2. H. Lammer
3. F. Tian
4. J. Castillo‐Rogez
5. D. Rubie
6. D. Frost
7. E. Chassefière
8. F. Nimmo

In Geophysics

1. D. Rubie
2. U. Mann
3. Y. Asahara
4. P. Kegler
5. J. Castillo‐Rogez
6. F. Tian
7. K. Tsuno
8. H. Lammer

In Mechanics of Materials

1. J. Kasting

Citations in the corpus

• Heterogeneous accretion, composition and core–mantle differentiation of the Earth (2011, background): “The major gaseous species in equilibrium with ordinary chondrites at high temperatures are CH4 and H2 and the major S-bearing species is H2S (Schaefer and Fegley, 2007).”
• Atmospheric Escape and Evolution of Terrestrial Planets and Satellites (2008, background): “Alternatively, an atmosphere rich in these highly reduced gases could have been produced by impacts, especially those that occurred during the earlier stages of accretion when elemental iron-rich impactors were still abundant (Schaefer and Fegley 2007; Hashimoto et al. 2007).”
• Ceres’ evolution and present state constrained by shape data (2010, background): “…effect of 26Al heating provided during the accretion, although the latter could have contributed to early melting, possible aqueous alteration of the silicate phase in the growing protoplanet (Young, 2001; Travis and Schubert, 2005), and possible early degassing (e.g., Schaefer and Fegley, 2007).”
• Composition and fate of short-period super-Earths: The case of CoRoT-7b (2009, unknown): “A first consequence of a molten surface is that volatiles should be efficiently outgassed from the planetary interior (e.g. Schaefer & Fegley, 2007).”