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TitreCrustal structure and tectonic framework of the Canadian Arctic margin: New insights on the development of the Amerasia Basin
AuteurOakey, G N; Saltus, R W; Chian, D; Jackson, H R; Shimeld, J; Brozena, J M; Funck, T; Dahl-Jensen, T
SourceAmerican Geophysical Union Annual Convention 2013, abstracts; .
Séries alt.Secteur des sciences de la Terre, Contribution externe 20140036
ÉditeurAmerican Geophysical Union
RéunionAmerican Geophysical Union Annual Convention 2013; US; 2013
Documentlivre
Lang.anglais
Mediapapier
ProgrammePreparation of a submission for an extended continental shelf in the Atlantic and Arctic Oceans under UNCLOS, Délimitation du plateau continental du Canada en vertu de la Convention des Nations Unies sur le droit de la mer (UNCLOS)
Résumé(disponible en anglais seulement)
A significant volume of new Arctic geophysical data have been collected over the last decade during collaborative Canadian, American, and Danish research expeditions. These data have been integrated with pre-existing geophysical data sets (e.g., US Naval Research Lab airborne gravity and magnetic surveys) to constrain models for the crustal structure and tectonic evolution of the Amerasia Basin.
2-D gravity and magnetic models have been generated for cross-sections of the Canadian margin, Chukchi Plateau, Alpha Ridge and Lomonosov Ridge. The models are constrained using seismic reflection and refraction data. The models illustrate the variability of different segments of the rifted margins as well as the distribution of magnetized crust and volcanic units. Density values for all of the models are based on standard velocity-density relationships.
The models support the velocity analysis of the sonobuoy data that true oceanic crust is present only in a narrow central portion of Canada Basin and that most of the basin is underlain by hyper-extended continental crust and/or 'transitional' crust with localized high-velocity/density sub-crustal layers. Moho depths beneath Canada Basin range from 18 to 22 km.
Moho depths beneath the Alpha Ridge are considerably deeper (25 to 30 km) than those in the adjacent Canada Basin. The upper crust of Alpha Ridge is modeled with continental densities in the upper crust underlain by a thick lower crust with an intermediate density. This crustal character is consistent with the formation of the Alpha Ridge by intrusion of a large igneous province (the High Arctic Large Igneous Province - HALIP) into continental crust.
Résumé(Résumé en langage clair et simple, non publié)
Un volume important de nouvelles données géophysiques de l'Arctique ont été collectées au cours de la dernière décennie au cours de la collaboration canadienne, américaine, et des expéditions de recherche danois pour soutenir prolongée présentation du plateau continental du Canada auprès des Nations Unies. Afin de mieux comprendre la structure géologique de la marge Canadain l'Arctique, la gravité et les modèles magnétiques ont été générées pour plusieurs coupes pour illustrer la variabilité des différents segments de la marge de divergence ainsi que la répartition de la croûte magnétisée et les unités volcaniques.
GEOSCAN ID293932