Abstract
THE electrical conductivity of the lower mantle, which controls the transmission of geomagnetic signals to the Earth's surface, has been the subject of recent controversy1,2. Peyronneau and Poirier1 extrapolated high-pressure conductivity measurements of the lower-mantle assemblage (Mg, Fe)SiO3 perovskite plus (Mg, Fe)O magnesiowüstite from 673 K to lower-mantle temperatures (2,200–2,500 K) to obtain conductivities consistent with geomagnetic observations (∼ 1 S m−1 at 1,000-km depth). The high-pressure study of Li and Jeanloz2 gave conductivities several orders of magnitude lower. Here we report measurements of conductivity and thermopower of the iron-rich phase (Mg, Fe)O at high temperature (1,173–1,773 K) and controlled oxygen partial pressure (pO2). We find that pO2 has a very large influence on conductivity: at fixed temperature and pressure, changes in pO2 can vary the conductivity by 1.5 orders of magnitude within the stability field of magnesiowüstite. For plausible mantle values of pO2, temperature and bulk composition, we obtain results in good agreement with those of ref. 1, indicating that magnesiowüstite is the dominant conductor in the lower mantle and that observed upper- and lower-mantle conductivities can be produced by the same bulk composition.
This is a preview of subscription content, access via your institution
Access options
Subscribe to this journal
Receive 51 print issues and online access
$199.00 per year
only $3.90 per issue
Buy this article
- Purchase on Springer Link
- Instant access to full article PDF
Prices may be subject to local taxes which are calculated during checkout
Similar content being viewed by others
References
Peyronneau, J. & Poirier, J.-P. Nature 342, 537–539 (1989).
Li, X. & Jeanloz, R. J. geophys. Res. 95, 5067–5078 (1990).
Ito, E. & Takahashi, E. J. geophys. Res. 94, 10637–10646 (1989).
Wood, B. J. J. geophys. Res. 95, 12681–12685 (1990).
Hinze, E., Will, G. & Cemic, L. Phys. Earth planet. Inter. 25, 245–254 (1981).
Nell, J., Wood B. J. & Mason T. O. Am. Miner. 84, 339–351 (1989).
Iyengar, G. N. K. & Alcock, C. B. Phil. Mag. 21, 293–304 (1970).
Chen, W-K. & Peterson, N. L. J. Phys. Chem. Solids 41, 335–339 (1980).
Mao, H. K. Yb. Carnegie Inst. Wash. 72, 554–557 (1973).
Li, X. & Jeanloz, R. J. geophys. Res. 95, 21609–21612 (1990).
Brynestad, J. & Flood, H. Elektrochem. Ber. Bunsenges. Phys. Chem. 62, 953–958 (1958).
Valet, P.-M., Pluschkell, W. & Engell, H.-J. Arch. Eisenhüttenwes. 46, 383–388 (1975).
Gartstein, E., Cohen, J. B. & Mason, T. O. J. Phys. Chem. Solids 47, 775–781 (1986).
Hirsch, L. M. & Shankland, T. J. J. geophys. Res. 96, 385–403 (1991).
Chaikin, P. M. & Beni, G. Phys. Rev. B13, 647–651 (1976).
Wu, C. C. & Mason, T. O. J. Am. Ceram. Soc. 64, 520–522 (1981).
Poirier, J-P & Peyronneau, J. Proc. US-Japan High Pressure Miner. Phys. Symp. (in the press).
Wood, B. J., Bryndzia, L. T. & Johnson, K. E. Science 248, 337–345 (1990).
Webman, I., Jortner, J. & Cohen, M. H. Phys. Rev. B14, 4737–4740 (1976).
Sempolinski, D. R. & Kingery, W. D. J. Am. Ceram. Soc. 63, 664–669 (1980).
Ito, K. & Kennedy, G. C. Am. J. Sci. 265, 519–538 (1967).
Nehru, C. E. & Wyllie, P. J. J. Geol. 83, 455–471 (1975).
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Wood, B., Nell, J. High-temperature electrical conductivity of the lower-mantle phase (Mg, Fe)O. Nature 351, 309–311 (1991). https://doi.org/10.1038/351309a0
Received:
Accepted:
Issue Date:
DOI: https://doi.org/10.1038/351309a0
This article is cited by
-
The influence of ferric iron and hydrogen on Fe–Mg interdiffusion in ferropericlase ((Mg,Fe)O) in the lower mantle
Physics and Chemistry of Minerals (2015)
-
Laboratory Electrical Conductivity Measurement of Mantle Minerals
Surveys in Geophysics (2010)
-
Determining the composition of the Earth
Nature (2002)
-
Studies of electrical properties of rocks under high temperature and pressure
Acta Seismologica Sinica (1999)
-
Electrical conductivity of silicate perovskite at lower-mantle conditions
Nature (1998)
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.