Properties of Rocks and Minerals - The Electrical Conductivity of Rocks, Minerals, and the Earth

Research output: Chapter in Book/Report/Conference proceedingChapter

10 Scopus citations

Abstract

The electrical conductivity of mantle and transition-zone minerals is known with reasonable precision and can be used to model the deep Earth. In olivine, small polarons (Fe3+ on an Mg-site) and magnesium vacancies govern the conductivity at oxygen fugacities of the mantle. Their relative importance varies with temperature; small polarons dominate at lower temperatures with magnesium vacancies playing a greater role at higher temperatures. The dominant conducting species at low oxygen fugacity are less well constrained. Multianvil high-pressure electrical conductivity measurements of mantle and transition-zone minerals (olivine, pyroxene, wadsleyite, ringwoodite, ilmenite, and perovskite) indicate that polarons also govern conductivity in these materials. Hydrogen in these minerals greatly enhances electrical conductivity but the conduction occurs by a mechanism different from that of hydrogen diffusion. Mineral physics-based mantle-conductivity models constructed to fit resistivity and phase results of magnetotelluric studies offer the potential for mapping hydrogen in the mantle and other phases or species that cause high conductivity.

Original languageEnglish (US)
Title of host publicationTreatise on Geophysics
PublisherElsevier
Pages631-642
Number of pages12
Volume2
ISBN (Print)9780444527486
DOIs
StatePublished - Dec 1 2007

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Keywords

  • Defects
  • Diffusion
  • Electrical conductivity
  • Grain boundaries
  • High pressure
  • Hydrogen in minerals
  • Magnesiowüstite
  • Magnetotellurics
  • Mantle
  • Melt
  • Olivine
  • Oxygen fugacity
  • Partial melt
  • Perovskite
  • Polarons
  • Ringwoodite
  • Transition zone
  • Vacancies
  • Wadsleyite

ASJC Scopus subject areas

  • Earth and Planetary Sciences(all)

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