Accretion of the Earth and segregation of its core.

Journal article

The Earth took 30-40 million years to accrete from smaller 'planetesimals'. Many of these planetesimals had metallic iron cores and during growth of the Earth this metal re-equilibrated with the Earth's silicate mantle, extracting siderophile ('iron-loving') elements into the Earth's iron-rich core. The current composition of the mantle indicates that much of the re-equilibration took place in a deep (> 400 km) molten silicate layer, or 'magma ocean', and that conditions became more oxidizing with time as the Earth grew. The high-pressure nature of the core-forming process led to the Earth's core being richer in low-atomic-number elements, notably silicon and possibly oxygen, than the cores of the smaller planetesimal building blocks.

Authors: Wood, B; Walter, M; Wade, J

• Publication status: Published
• Journal: Nature
• Volume: 441
• Issue: 7095
• Pages: 825-833
• Publication date: 2006-06-01
• DOI: 10.1038/nature04763
• EISSN: 1476-4687
• ISSN: 0028-0836
• Language: English