Electrical conductivity of (Mg,Fe)SiO3 perovskite and a perovskite‐dominated assemblage at lower mantle conditions
- 1 November 1987
- journal article
- Published by American Geophysical Union (AGU) in Geophysical Research Letters
- Vol. 14 (11) , 1075-1078
- https://doi.org/10.1029/gl014i011p01075
Abstract
Electrical conductivity measurements of perovskite and a perovskite‐dominated assemblage synthesized from pyroxene ((Mg0.88Fe0.12)SiO3) and olivine ((Mg0.88Fe0.12)2SiO4) demonstrate that these high‐pressure phases are insulating to pressures of 82 GPa and temperatures of 4500 K. Assuming an anhydrous upper mantle composition, our result provides an upper bound of 10−2 S m−1 for the electrical conductivity of the lower mantle between depths of 700 and 1900 km. This is 2 to 4 orders of magnitude lower than previous estimates of lower‐mantle conductivity derived from studies of geomagnetic secular variations.Keywords
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