| Titre | The crustal structure of the Alpha Ridge at the transition to the Canadian Polar margin - results from a seismic refraction experiment |
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| Auteur | Funck, T; Jackson, H R; Shimeld, J |
| Source | Journal of Geophysical Research vol. 116, issue B12, B12101, 2011 p. 1-26, https://doi.org/10.1029/2011jb008411  Accès ouvert |
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| Année | 2011 |
| Séries alt. | Secteur des sciences de la Terre, Contribution externe 20110132 |
| Éditeur | Wiley-Blackwell |
| Document | publication en série |
| Lang. | anglais |
| DOI | https://doi.org/10.1029/2011jb008411 |
| Media | papier; en ligne; numérique |
| Formats | pdf |
| Province | Région extracotière du nord |
| Région | Océan Arctique; Canadian Polar Margin |
| Lat/Long OENS | -100.0000 -90.0000 84.3333 80.0000 |
| Sujets | données sismiques; profils sismiques; levés de refraction sismiques; ondes P; modèles de la croûte; croûte océanique; géologie marine; géophysique |
| Illustrations | cartes de localisation; profils sismiques; coupes schématiques transversales; cartes d'anomalies magnétiques |
| Programme | Délimitation du plateau continental du Canada en vertu de la Convention des Nations Unies sur le droit de la mer (UNCLOS) |
| Diffusé | 2011 12 03 |
| Résumé | (disponible en anglais seulement)
The crustal structure of the Alpha Ridge and its connection to the Canadian Polar Margin was studied by a seismic refraction experiment consisting of a
350-km-long line perpendicular to the margin and of a 175-km-long cross line on the ridge. Explosives with a spacing of 22 km were recorded by geophones deployed on the ice (~1.5 km spacing). P wave velocity models were developed by forward and
inverse modeling of travel times and by tomographic inversion. The models show a 30-km-thick continental crust with velocities from 5.5-6.6 km/s. The continent-ocean transition zone is characterized by thinned and intruded continental crust; a
high-velocity lower crustal body (7.5 km/s) indicates magmatic underplating. An up to 5-km-thick layer with velocities of 4.7-5.4 km/s can be correlated from the transition zone onto the Alpha Ridge, where reflection seismic data indicate the
presence of extrusive volcanics. The transition zone is characteristic for volcanic-style continental margins. The crust on Alpha Ridge consists of the volcanics, a 4-km-thick layer with intermediate velocities of 6.1-6.6 km/s and a lower crustal
layer with velocities of 6.8 to 7.3 km/s; Moho depth varies between 26 and 32 km. Velocities on the ridge are similar to other oceanic large igneous provinces. The Alpha Ridge and the contiguous Mendeleev Ridge are interpreted to result from
interaction between a Cretaceous plume and a seafloor spreading centre parallel to the Canadian Polar Margin with the Lomonosov Ridge acting as a shear margin. |
| GEOSCAN ID | 289075 |
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