Open AccessSEO3: A new model of olivine electrical conductivity
Author(s) -
Constable Steven
Publication year - 2006
Publication title -
geophysical journal international
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.302
H-Index - 168
eISSN - 1365-246X
pISSN - 0956-540X
DOI - 10.1111/j.1365-246x.2006.03041.x
Subject(s) - mineral redox buffer , olivine , extrapolation , electrical resistivity and conductivity , mantle (geology) , fugacity , conductivity , mineralogy , geology , pyroxene , thermodynamics , polaron , materials science , geophysics , chemistry , physics , quantum mechanics , mathematical analysis , mathematics , electron
SUMMARY Standard Electrical Olivine 3 (SEO3) is a new model of electrical conductivity for olivine as a function of temperature and oxygen fugacity, and is based on a previous study of point defect behaviour in a dunite. That study produced quantitative estimates of mobility and concentration for small polarons and magnesium vacancies as a function of temperature and oxygen fucacity. Unlike earlier SO1 and SO2 models of olivine conductivity, the dunite sample was buffered by pyroxene, and avoided alteration at high temperature. The low‐temperature extrapolation produced by SEO3 is in good agreement with SO2, while the high‐temperature extrapolation is significantly more conductive, which is in general agreement with many field studies that show the Earth's upper mantle to be more conductive than predicted by SO2 for reasonable temperatures. Plausible variations in mantle oxygen fugacity correspond to about half an order of magnitude variation in electrical conductivity, equivalent to about 100 degrees in temperature.