Electrical conductivities of olivine, quartz, garnet, corundum, jadeite and alkali feldspar are measured over the temperature range 500 to 1200°K. Electrical conductivities σ of these rock-forming minerals can be expressed by an equation similar to that for semi-conductors;
σ=σ
01exp(-ε
1/kT)+σ
02exp(-ε
2/kT)+…
where ε
i's are the activation energies, k, Boltzmann constant and σ
0i's, constants. Although the type of conduction mechanism cannot be determined definitely, the activation energies of various rock-forming minerals fall between 0.7 and 1.7eV over the temperature range studied. The pre-exponential term σ
0i, however, varies several orders of magnitude for different minerals.
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