Encyclopedia of Astrobiology

Living Edition
| Editors: Muriel Gargaud, William M. Irvine, Ricardo Amils, Henderson James Cleaves, Daniele Pinti, José Cernicharo Quintanilla, Michel Viso

Late Veneer

Living reference work entry
DOI: https://doi.org/10.1007/978-3-642-27833-4_870-4

Definition

The term late veneer refers to the late accretion of asteroidal or cometary material to terrestrial planets. Iron and nickel segregation during core formation leaves the mantle of the planets depleted in siderophile elements, notably platinum-group elements. The modern abundances of these elements in the terrestrial mantle greatly exceed the level expected from such a wholesale removal of metal. It is therefore surmised that 0.5–1.5 % of chondritic or cometary material was brought to the planet by the late veneer after core formation (Dauphas and Marty 2002; Maier et al. 2009). This hypothesis is germane to the issue of water delivery to the Earth.

History

Ringwood (1966) pointed out that the abundances of siderophile elements such as Ni, Co, Pt, and Os in the upper mantle are remarkably higher than the values indicated by low-pressure partitioning experiments of these elements between metal and silicate phases. Chou (1978) suggested that about one percent of material...

Keywords

Solar System Giant Planet Carbonaceous Chondrite Core Formation Outer Solar System 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.
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References and Further Reading

  1. Albarède F (2009) Volatile accretion history of the terrestrial planets and dynamic implications. Nature 461:1227–1233ADSCrossRefGoogle Scholar
  2. Chou CL (1978) Fractionation of siderophile elements in the Earth’s upper mantle. Proc Lunar Planet Sci Conf 9:219–230ADSGoogle Scholar
  3. Dauphas N, Marty B (2002) Inference on the nature and the mass of Earth’s late veneer from noble metals and gases. J Geophys Res-Planets 107:doi:10.1029/2001JE001617Google Scholar
  4. Drake M, Righter K (2002) Determining the composition of the Earth. Nature 416:39–44ADSCrossRefGoogle Scholar
  5. Gomes R, Levison HF, Tsiganis K, Morbidelli A (2005) Origin of the cataclysmic Late Heavy Bombardment period of the terrestrial planets. Nature 435:466–469ADSCrossRefGoogle Scholar
  6. Holzheid A et al (2000) Evidence for a late chondritic veneer in the Earth’s mantle from high-pressure partitioning of palladium and platinum. Nature 406:396–399ADSCrossRefGoogle Scholar
  7. Li J, Agee CB (1996) Geochemistry of mantle-core differentiation at high pressure. Nature 381:686–689ADSCrossRefGoogle Scholar
  8. Maier WD, Barnes SJ, Campbell IH, Fiorentini ML, Peltonen P, Barnes S-J, Smithies RH (2009) Progressive mixing of meteoritic veneer into the early Earth’s deep mantle. Nature 460:620–623ADSCrossRefGoogle Scholar
  9. Morbidelli A et al (2000) Source regions and time scales for the delivery of water to the Earth. Meteorit Planet Sci 35:1309–1320ADSCrossRefGoogle Scholar
  10. Owen T, Bar-Nun A (1995) Comets, impacts, and atmospheres. Icarus 116:215–226ADSCrossRefGoogle Scholar
  11. Ringwood AE (1966) The chemical composition and origin of the earth. In: Hurley PM (ed) Advances in earth sciences. The M.I.T. Press, Cambridge, pp 287–356Google Scholar
  12. Wade J, Wood BJ (2005) Core formation and the oxidation state of the Earth. Earth Planet Sci Lett 236:78–95ADSCrossRefGoogle Scholar

Copyright information

© Springer-Verlag Berlin Heidelberg 2014

Authors and Affiliations

  1. 1.Ecole Normale Supérieure de LyonLyon Cedex 7France