Service interruption on Monday 11 July from 12:30 to 13:00: all the sites of the CCSD (HAL, Epiciences, SciencesConf, AureHAL) will be inaccessible (network hardware connection).
Skip to Main content Skip to Navigation
Journal articles

Deformation-aided segregation of Fe -S liquid from olivine under deep Earth conditions: Implications for core formation in the early solar system

Abstract : The planets and larger rocky bodies of the inner solar system are differentiated, and consist of metallic, iron-rich cores surrounded by thick shells of silicate. Core formation in these bodies, i.e. the segregation of metal from silicate, was a key process in the early solar system, and one which left a lasting geochemical signature. It is commonly assumed that extensive silicate melting and formation of deep magma oceans was required to initiate core formation, due to the inability of iron-rich melts to segregate from a solid silicate matrix. Here we assess the role of deformation in aiding segregation of core-forming melts from solid silicate under conditions of planetary deep interiors. Low-strain rate, high-pressure/ temperature deformation experiments and high-resolution 2-D and 3-D textural analysis demonstrate that deformation fundamentally alters iron-rich melt geometry, promoting wetting of silicate grain boundaries and formation of extensive micron to sub-micron width Fe-rich melt bands. Deformation aided Fe-S melt networks noted here contrast those observed in higher finite strain experiments conducted at lower pressure, and may reveal either an alternative mechanism for melt segregation at higher pressures, or an early stage process of melt segregation. Results suggest, however, that core-mantle chemical equilibration cannot be assumed in models of planetary formation, and that instead, the chemistry of rocky planets may record a complex, multi-stage process of core formation. Crown Copyright (c) 2017 Published by Elsevier B.V.
Document type :
Journal articles
Complete list of metadata
Contributor : Depot 2 Lyon 1 Connect in order to contact the contributor
Submitted on : Monday, September 20, 2021 - 3:56:11 PM
Last modification on : Wednesday, November 3, 2021 - 5:36:58 AM
Long-term archiving on: : Tuesday, December 21, 2021 - 7:07:14 PM


Publisher files allowed on an open archive


Distributed under a Creative Commons Attribution 4.0 International License




Madeleine T. L. Berg, Geoffrey D. Bromiley, Ian B. Butler, Mungo Frost, Robert Bradley, et al.. Deformation-aided segregation of Fe -S liquid from olivine under deep Earth conditions: Implications for core formation in the early solar system. Physics of the Earth and Planetary Interiors, 2017, 263, pp.38-54. ⟨10.1016/j.pepi.2017.01.004⟩. ⟨hal-02329279⟩



Record views


Files downloads