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TitreDetection of widespread fluids in the Tibetan crust by magnetotelluric studies
AuteurWei, W; Unsworth, M; Jones, A; Booker, J; Tan, H; Nelson, D; Chen, L; Li, S; Solon, K; Bedrosian, P; Jin, S; Deng, M; Ledo, J; Kay, D; Roberts, B
SourceScience vol. 292, no. 5517, 2001 p. 716-718
Année2001
Séries alt.Commission géologique du Canada, Contributions aux publications extérieures 2000155
Documentpublication en série
Lang.anglais
Mediapapier
Lat/Long OENS 86.0000 96.0000 40.0000 26.0000
Sujetsétudes de la croûte; croûte continentale; interprétations magnétotelluriques; levés magnétotelluriques; conductivité; levés de conductivité; fusion partielle; déformation; épaisseur de la croûte; cadre tectonique; géophysique; pétrologie ignée et métamorphique; géologie structurale; tectonique
Illustrationslocation maps; graphs; resistivity profiles
Résumé(disponible en anglais seulement)
Magnetotelluric exploration has shown that the middle and lower crust is anomalously conductive across most of the north-to-south width of the Tibetan plateau. The integrated conductivity (conductance) of the Tibetan crust ranges from 3000 to greater than 20,000 siemens. In contrast, stable continental regions typically exhibit conductances from 20 to 1000 siemens, averaging 100 siemens. Such pervasively high conductance suggests that partial melt and/or aqueous fluids are widespread within the Tibetan crust. In southern Tibet, the high-conductivity layer is at a depth of 15 to 20 kilometers and is probably due to partial melt and aqueous fluids in the crust. In northern Tibet, the conductive layer is at 30 to 40 kilometers and is due to partial melting. Zones of ßuid may represent weaker areas that could accommodate deformation and lower crustal flow.
GEOSCAN ID211702