Core formation and core composition from coupled geochemical and geophysical constraints

• DOI: 10.1073/pnas.1505672112
• Publication Date: 2015-09-22T03:08:42Z
• Authors: James Badro; John P. Brodholt; Hélène Piet; Julien Siebert; Frederick J. Ryerson
• Keywords: Trace element; Outer core

Significance We combine, for the first time to our knowledge, two approaches study Earth’s core composition: a geochemical approach based on trace element depletion in mantle and geophysical seismically lighter faster (than pure iron−nickel) core. The joint allows making strong statements; of all, as opposed current belief, Earth must have accreted material that is more oxidized than present-day mantle, similar planetesimals such 4-Vesta, got reduced its present state during formation. Secondly, light-element concentrations those conditions are 2.7% 5% oxygen alongside 2% 3.6% silicon; higher previously thought, and, conversely, silicon lower previous estimates.