Skip to main content

Thank you for visiting nature.com. You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

  • Letter
  • Published:

A perovskitic lower mantle inferred from high-pressure, high-temperature sound velocity data

Abstract

The determination of the chemical composition of Earth’s lower mantle is a long-standing challenge in earth science. Accurate knowledge of sound velocities in the lower-mantle minerals under relevant high-pressure, high-temperature conditions is essential in constraining the mineralogy and chemical composition using seismological observations1, but previous acoustic measurements were limited to a range of low pressures and temperatures. Here we determine the shear-wave velocities for silicate perovskite and ferropericlase under the pressure and temperature conditions of the deep lower mantle using Brillouin scattering spectroscopy2. The mineralogical model that provides the best fit to a global seismic velocity profile1 indicates that perovskite constitutes more than 93 per cent by volume of the lower mantle, which is a much higher proportion than that predicted by the conventional peridotitic mantle model. It suggests that the lower mantle is enriched in silicon relative to the upper mantle, which is consistent with the chondritic Earth model. Such chemical stratification implies layered-mantle convection with limited mass transport between the upper and the lower mantle.

This is a preview of subscription content, access via your institution

Access options

Buy this article

Prices may be subject to local taxes which are calculated during checkout

Figure 1: Brillouin spectra of lower-mantle phases.
Figure 2: Shear velocity for lower-mantle phases.
Figure 3: Effect of aluminium and iron on shear modulus and its pressure derivative.
Figure 4: Lower-mantle geotherms and calculated shear- and longitudinal-wave velocity profiles for whole-mantle and layered-mantle convection models.

Similar content being viewed by others

References

  1. Dziewonski, A. M. & Anderson, D. L. Preliminary reference Earth model. Phys. Earth Planet. Inter. 25, 297–356 (1981)

    Article  ADS  Google Scholar 

  2. Murakami, M. et al. Development of in-situ Brillouin spectroscopy at high pressure and temperature with synchrotron radiation and infrared laser heating system: application to the Earth’s deep interior. Phys. Earth Planet. Inter. 174, 282–291 (2009)

    Article  ADS  CAS  Google Scholar 

  3. Ringwood, A. E. Composition and Petrology of the Earth’s Mantle (McGraw Hill, 1975)

    Google Scholar 

  4. Sun, S. S. Chemical-composition and origin of the Earth’s primitive mantle. Geochim. Cosmochim. Acta 46, 179–192 (1982)

    Article  ADS  CAS  Google Scholar 

  5. Ito, E. & Takahashi, E. Postspinel transformations in the system Mg2SiO4-Fe2SiO4 and some geophysical implications. J. Geophys. Res. 94, 10637–10646 (1989)

    Article  ADS  Google Scholar 

  6. Allègre, C. J., Poirier, J. P., Humler, E. & Hofmann, A. W. The chemical composition of the earth. Earth Planet. Sci. Lett. 134, 515–526 (1995)

    Article  ADS  Google Scholar 

  7. Tonks, W. B. & Melosh, H. J. Magma ocean formation due to giant impact. J. Geophys. Res. 98, 5319–5333 (1993)

    Article  ADS  Google Scholar 

  8. Ringwood, A. E. Significance of the terrestrial Mg/Si ratio. Earth Planet. Sci. Lett. 95, 1–7 (1989)

    Article  ADS  CAS  Google Scholar 

  9. Fei, Y. et al. Spin transition and equations of state of (Mg, Fe)O solid solutions. Geophys. Res. Lett. 34, L17307 (2007)

    Article  ADS  Google Scholar 

  10. Ricolleau, A. et al. Density profile of pyrolite under the lower mantle conditions. Geophys. Res. Lett. 36, L06302 (2009)

    Article  ADS  Google Scholar 

  11. Mattern, E., Matas, J., Ricard, Y. & Bass, J. Lower mantle composition and temperature from mineral physics and thermodynamic modelling. Geophys. J. Int. 160, 973–990 (2005)

    Article  ADS  CAS  Google Scholar 

  12. Murakami, M., Sinogeikin, S. V., Hellwig, H., Bass, J. D. & Li, J. Sound velocity of MgSiO3 perovskite to Mbar pressure. Earth Planet. Sci. Lett. 256, 47–54 (2007)

    Article  ADS  CAS  Google Scholar 

  13. Murakami, M. et al. Sound velocity of MgSiO3 post-perovskite phase: a constraint on the D′′ discontinuity. Earth Planet. Sci. Lett. 259, 18–23 (2007)

    Article  ADS  CAS  Google Scholar 

  14. Murakami, M., Ohishi, Y., Hirao, N. & Hirose, K. Elasticity of MgO to 130GPa: implications for lower mantle mineralogy. Earth Planet. Sci. Lett. 277, 123–129 (2009)

    Article  ADS  CAS  Google Scholar 

  15. Brodholt, J. P. Pressure-induced changes in the compression mechanism of aluminous perovskite in the Earth’s mantle. Nature 407, 620–622 (2000)

    Article  ADS  CAS  Google Scholar 

  16. Jackson, J. M., Zhang, J. & Bass, J. D. Sound velocities and elasticity of aluminous MgSiO3 perovskite: implications for aluminum heterogeneity in Earth’s lower mantle. Geophys. Res. Lett. 31, L10614 (2004)

    Article  ADS  Google Scholar 

  17. Jackson, J. M., Zhang, J., Shu, J., Sinogeikin, S. V. & Bass, J. D. High-pressure sound velocities and elasticity of aluminous MgSiO3 perovskite to 45 GPa: implications for lateral heterogeneity in Earth’s lower mantle. Geophys. Res. Lett. 32, L21305 (2005)

    Article  ADS  Google Scholar 

  18. Badro, J. et al. Iron partitioning in Earth’s mantle: toward a deep lower mantle discontinuity. Science 300, 789–791 (2003)

    Article  ADS  CAS  Google Scholar 

  19. Crowhurst, J. C., Brown, J. M., Goncharov, A. F. & Jacobsen, S. D. Elasticity of (Mg,Fe)O through the spin transition of iron in the lower mantle. Science 319, 451–453 (2008)

    Article  ADS  CAS  Google Scholar 

  20. Marquardt, H., Speziale, S., Reichmann, H. J., Frost, D. J. & Schilling, F. R. Single-crystal elasticity of (Mg0. 9Fe0. 1)O to 81 GPa. Earth Planet. Sci. Lett. 287, 345–352 (2009)

    Article  ADS  CAS  Google Scholar 

  21. Stixrude, L. & Lithgow-Bertelloni, C. Thermodynamics of mantle minerals - I. Physical properties. Geophys. J. Int. 162, 610–632 (2005)

    Article  ADS  Google Scholar 

  22. Kennett, B. L. N. & Jackson, I. Optimal equations of state for mantle minerals from simultaneous non-linear inversion of multiple datasets. Phys. Earth Planet. Inter. 176, 98–108 (2009)

    Article  ADS  CAS  Google Scholar 

  23. Jackson, J. M. et al. Single-crystal elasticity and sound velocities of (Mg0. 94Fe0. 06)O ferropericlase to 20 GPa. J. Geophys. Res. 111, B09203 (2006)

    Article  ADS  Google Scholar 

  24. Jacobsen, S. D. et al. Structure and elasticity of single-crystal (Mg,Fe)O and a new method of generating shear waves for gigahertz ultrasonic interferometry. J. Geophys. Res. 107, 2037 (2002)

    Article  ADS  Google Scholar 

  25. Kung, J., Li, B. S., Weidner, D. J., Zhang, J. Z. & Liebermann, R. C. Elasticity of (Mg0. 83,Fe0. 17)O ferropericlase at high pressure: ultrasonic measurements in conjunction with X-radiation techniques. Earth Planet. Sci. Lett. 203, 557–566 (2002)

    Article  ADS  CAS  Google Scholar 

  26. Jackson, I. & Rigden, S. M. in The Earth’s Mantle: Composition, Structure and Evolution (ed. Jackson, I. ) 405–460 (Cambridge Univ. Press, 1998)

    Book  Google Scholar 

  27. Brown, J. M. & Shankland, T. J. Thermodynamic parameters in the Earth as determined from seismic profiles. Geophys. J. R. Astron. Soc. 66, 579–596 (1981)

    Article  ADS  Google Scholar 

  28. Anderson, O. L. The Earth’s core and the phase-diagram of iron. Phil. Trans. R. Soc. Lond.. A 306, 21–35 (1982)

    Article  ADS  CAS  Google Scholar 

  29. Li, L. et al. Elasticity of CaSiO3 perovskite at high pressure and high temperature. Earth Planet. Sci. Lett. 155, 249–259 (2006)

    Article  CAS  Google Scholar 

  30. Stixrude, L., Lithgow-Bertelloni, C., Kiefer, B. & Fumagalli, P. Phase stability and softening in CaSiO3 perovskite at high pressure. Phys. Rev. B 75, 024108 (2007)

    Article  ADS  Google Scholar 

  31. Christensen, U. R. & Yuen, D. A. Layered convection induced by phase-transitions. J. Geophys. Res. 90, 10291–10300 (1985)

    Article  ADS  Google Scholar 

  32. van der Hist, R., Engdahl, R., Spakman, W. & Nolet, G. Tomographic imaging of subducted lithosphere below northwest Pacific island arcs. Nature 353, 37–43 (1991)

    Article  ADS  Google Scholar 

  33. Tange, Y., Nishihara, Y. & Tsuchiya, T. Unified analyses for P-V-T equation of state of MgO: a solution for pressure-scale problems in high P-T experiments. J. Geophys. Res. 115, B12203 (2010)

    Article  ADS  Google Scholar 

  34. Murakami, M., Hirose, K., Kawamura, K., Sata, N. & Ohishi, Y. Post-perovskite phase transition in MgSiO3 . Science 304, 855–858 (2004)

    Article  ADS  CAS  Google Scholar 

  35. Akahama, Y. & Kawamura, H. High-pressure Raman spectroscopy of diamond anvils to 250 GPa: method for pressure determination in the multimegabar pressure range. J. Appl. Phys. 96, 3748–3751 (2004)

    Article  ADS  CAS  Google Scholar 

  36. Sata, N., Shen, G., Rivers, M. L. & Sutton, S. R. Pressure-volume equation of state of the high-pressure B2 phase of NaCl. Phys. Rev. B 65, 104114 (2002)

    Article  ADS  Google Scholar 

  37. Holmes, N. C., Moriarty, J. A., Gathers, G. R. & Nellis, W. J. The equation of state of platinum to 660 GPa (6.6Mbar). J. Appl. Phys. 66, 2962–2967 (1989)

    Article  ADS  CAS  Google Scholar 

  38. Dewaele, A., Fiquet, G., Andrault, D. & Hausermann, D. P-V-T equation of state of periclase from synchrotron radiation measurements. J. Geophys. Res. 105, 2869–2877 (2000)

    Article  ADS  CAS  Google Scholar 

Download references

Acknowledgements

We greatly appreciate the comments by I. Jackson. Suggestions from E. Ohtani, C. Bina, S. Karato and S.-H. Shim improved the manuscript. We also thank N. Sata and Y. Asahara for their experimental assistance at SPring-8. This study was performed under the approval of SPring-8 (proposals no. 2008B0099 and 2009A0087).

Author information

Authors and Affiliations

Authors

Contributions

M.M. planned the research and did experimental and analytical work. M.M. and K.H. wrote the paper. All authors were involved in the experiments and discussed the results.

Corresponding author

Correspondence to Motohiko Murakami.

Ethics declarations

Competing interests

The authors declare no competing financial interests.

Supplementary information

Supplementary Information

This file contains Supplementary Figures 1-2 and Supplementary Figures 1-6. (PDF 1519 kb)

PowerPoint slides

Rights and permissions

Reprints and permissions

About this article

Cite this article

Murakami, M., Ohishi, Y., Hirao, N. et al. A perovskitic lower mantle inferred from high-pressure, high-temperature sound velocity data. Nature 485, 90–94 (2012). https://doi.org/10.1038/nature11004

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1038/nature11004

This article is cited by

Comments

By submitting a comment you agree to abide by our Terms and Community Guidelines. If you find something abusive or that does not comply with our terms or guidelines please flag it as inappropriate.

Search

Quick links

Nature Briefing

Sign up for the Nature Briefing newsletter — what matters in science, free to your inbox daily.

Get the most important science stories of the day, free in your inbox. Sign up for Nature Briefing