Copyright © 2000 Elsevier Science Ltd. All rights reserved.
Article
Accretion and primary differentiation of the Earth: a personal journey
Received 13 November 1999;
References and further reading may be available for this article. To view references and further reading you must purchase this article.
Abstract
The accretion of the Earth was a violent series of events dominated by the addition of objects one third to one tenth of the mass of the growing planet. During the later stages of accretion, these collisions deposited enough energy to at least partly melt the Earth, possibly multiple times. The result was an ocean of magma. Metal sank through this magma ocean and ponded at its base at roughly the depth of the base of the current upper mantle for some period of time before transiting diapirically through the lower mantle to the center of the planet. Metal appears to have equilibrated with silicate at the base of the magma ocean. The primitive atmosphere and ocean appear to have outgassed from the magma ocean. Core formation, magma ocean solidification, ocean and atmospheric outgassing were essentially complete by 4.45 Ga ago.
Article Outline
- 1. Introduction
- 2. The “crime” and the “evidence”
- 3. Formation and accretion of the Earth
- 3.1. Metal-silicate equilibrium and the excess siderophile element problem
- 3.2. Heterogeneous accretion
- 3.3. Inefficient core formation
- 3.4. Core formation in a magma ocean environment
- 4. Solidification of the magma ocean
- 5. Formation of the primitive atmosphere and ocean
- 6. Discussion
- 7. Conclusions
- Acknowledgements
- References






E-mail Article
Add to my Quick Links

Cited By in Scopus (17)

4.0 wt.% dissolved H2O, whereas those for P remain unchanged only up to 




