Radiative conductivity and abundance of post-perovskite in the lowermost mantle

doi:https://doi.org/10.1016/j.epsl.2017.09.016

Title: Radiative conductivity and abundance of post-perovskite in the lowermost mantle

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Abstract

Thermal conductivity of the lowermost mantle governs the heat flow out of the core energizing planetary-scale geological processes. Yet, there are no direct experimental measurements of thermal conductivity at relevant pressure–temperature conditions of Earth's core–mantle boundary. Here we determine the radiative conductivity of post-perovskite at near core–mantle boundary conditions by optical absorption measurements in a laser-heated diamond anvil cell. Our results show that the radiative conductivity of Mg0.9Fe0.1SiO3 post-perovskite (~1.1 W/m/K) is almost two times smaller than that of bridgmanite (~2.0 W/m/K) at the base of the mantle. By combining this result with the present-day core–mantle heat flow and available estimations on the lattice thermal conductivity we conclude that post-perovskite is at least as abundant as bridgmanite in the lowermost mantle which has profound implications for the dynamics of the deep Earth.

Authors:

; Holtgrewe, Nicholas; Lin, Jung-Fu; Goncharov, Alexander F.

Publication Date:: 2017-12-01

Research Org.:: Argonne National Lab. (ANL), Argonne, IL (United States). Advanced Photon Source (APS)

Sponsoring Org.:: National Science Foundation (NSF)

OSTI Identifier:: 1410120

Resource Type:: Journal Article

Journal Name:: Earth and Planetary Science Letters

Additional Journal Information:: Journal Volume: 479; Journal Issue: C; Journal ID: ISSN 0012-821X

Publisher:: Elsevier

Country of Publication:: United States

Language:: ENGLISH

Subject:: 58 GEOSCIENCES

Citation Formats


                    Lobanov, Sergey S., Holtgrewe, Nicholas, Lin, Jung-Fu, and Goncharov, Alexander F. Radiative conductivity and abundance of post-perovskite in the lowermost mantle.  United States: N. p., 2017. 
        Web.  doi:10.1016/j.epsl.2017.09.016.

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                    Lobanov, Sergey S., Holtgrewe, Nicholas, Lin, Jung-Fu, & Goncharov, Alexander F. Radiative conductivity and abundance of post-perovskite in the lowermost mantle.  United States.  https://doi.org/10.1016/j.epsl.2017.09.016

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                    Lobanov, Sergey S., Holtgrewe, Nicholas, Lin, Jung-Fu, and Goncharov, Alexander F. Fri .  
        "Radiative conductivity and abundance of post-perovskite in the lowermost mantle".  United States.  https://doi.org/10.1016/j.epsl.2017.09.016.

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@article{osti_1410120,

  title        = {Radiative conductivity and abundance of post-perovskite in the lowermost mantle},

  author       = {Lobanov, Sergey S. and Holtgrewe, Nicholas and Lin, Jung-Fu and Goncharov, Alexander F.},

  abstractNote = {Thermal conductivity of the lowermost mantle governs the heat flow out of the core energizing planetary-scale geological processes. Yet, there are no direct experimental measurements of thermal conductivity at relevant pressure–temperature conditions of Earth's core–mantle boundary. Here we determine the radiative conductivity of post-perovskite at near core–mantle boundary conditions by optical absorption measurements in a laser-heated diamond anvil cell. Our results show that the radiative conductivity of Mg0.9Fe0.1SiO3 post-perovskite (~1.1 W/m/K) is almost two times smaller than that of bridgmanite (~2.0 W/m/K) at the base of the mantle. By combining this result with the present-day core–mantle heat flow and available estimations on the lattice thermal conductivity we conclude that post-perovskite is at least as abundant as bridgmanite in the lowermost mantle which has profound implications for the dynamics of the deep Earth.},

  doi          = {10.1016/j.epsl.2017.09.016},

  url          = {https://www.osti.gov/biblio/1410120},
  journal      = {Earth and Planetary Science Letters},

  issn         = {0012-821X},

  number       = C,

  volume       = 479,

  place        = {United States},

  year         = {2017},

  month        = {12}

}

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