Laboratory derived constraints on electrical conductivity beneath Slave craton
| Autor: | Sandrine Eichert, Nikolai Bagdassarov, Maya G. Kopylova |
|---|---|
| Rok vydání: | 2007 |
| Předmět: |
Peridotite
Arrhenius equation geography geography.geographical_feature_category Physics and Astronomy (miscellaneous) Astronomy and Astrophysics Geometry Crust Geophysics Activation energy Craton symbols.namesake Space and Planetary Science Electrical resistivity and conductivity Lithosphere symbols Xenolith Geology |
| Zdroj: | Physics of the Earth and Planetary Interiors. 161:126-133 |
| ISSN: | 0031-9201 |
| DOI: | 10.1016/j.pepi.2007.01.001 |
| Popis: | The depth profile of the electrical conductivity, σ ( d ) , beneath the Central Slave craton (Canada) has been reconstructed with the help of laboratory measurements carried out on peridotite xenoliths. σ ( T ) of xenoliths was determined in the piston-cylinder apparatus at 1 and 2 GPa and from 600 to 1150 ° C. σ ( T ) of xenoliths follows the Arrhenius dependence with the activation energy, E a , varying from 2.10 to 1.44 eV depending on temperature range and the Mg-number. The calculated xenolith geotherm and the suggested lithology beneath the Central Slave have been used to constrain σ ( d ) as follows: σ ( d ) in the crust varies between 0.5 × 1 0 − 5 and 1 0 − 3 S/m; the lithospheric σ ( d ) sharply decreases below the Moho at 39.4 km to 0.5 × 1 0 − 8 S/m, which corresponds to 460 ° C, and then gradually increases with the depth d to 0.5 × 1 0 − 2 S/m. The modeled MT-response of the constrained σ ( d ) profile has been compared with MT-observations [Jones, A.G., Lezaeta, P., Ferguson, I.J., Chave, A.D., Evans, R.L., Garcia, X., Spratt J., 2003. The electrical structure of the Slave craton. Lithos, 71, 505–527]. The general trend of the calculated MT-response based on the σ ( d ) model mimics the MT-inversion of the field data from the Central Slave. |
| Databáze: | OpenAIRE |
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