| Titre | The origin of the Alpha Ridge and its links to the High Arctic Large Igneous Province |
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| Auteur | Jackson, H R ;
Dossing, A; Funck, T; Shimeld, J |
| Source | St. John's 2012, Geoscience on the edge, abstracts/St. John's 2012, Géoscience de pointe, résumés; Association géologique du Canada-Association minéralogique du Canada, Réunion annuelle, Programme et
résumés vol. 35, 2012 p. 62  Accès ouvert |
| Liens | Online - En ligne (complete volume -
volume complet, PDF, 8.46 MB)
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| Année | 2012 |
| Séries alt. | Ressources naturelles Canada, Contribution externe 20190175 |
| Éditeur | Association géologique du Canada |
| Réunion | St. John's 2012: Geological Association of Canada (GAC)-Mineralogical Association of Canada (MAC) Joint Annual Meeting; St. John's, NL; CA; mai 27-29, 2012 |
| Document | publication en série |
| Lang. | anglais |
| Media | en ligne; numérique |
| Formats | pdf (Adobe® Reader®) |
| Programme | Délimitation du plateau continental du Canada en vertu de la Convention des Nations Unies sur le droit de la mer (UNCLOS) |
| Diffusé | 2012 05 01 |
| Résumé | (disponible en anglais seulement)
The formation of the Alpha Ridge and the significance of the widely distributed High Arctic Large Igneous Province (HALIP) have been an enigma due to lack of
direct evidence to constrain the geodynamic evolution of the region. A new 350 km long seismic refraction line was collected from the coast of northern Canada to the southern Alpha Ridge with a recorder spacing of 1.5 km and a shot spacing of 22 km
to define the sedimentary to Moho structure. Near the coast the crustal velocities are 5.6 - 6.5 km/s and the depth to Moho is 30 km, compatible with the adjacent continental crust. On the Alpha Ridge there is a near-seabed velocity of 4.7-5.4 km/s
interpreted as extrusive volcanics on the basis of seismic reflection and magnetic character. This layer is underlain by velocities of 6.1-6.6 km/s and 6.8-7.3 km/s, with Moho at depths of 26-32 km. The velocity structure of the Alpha Ridge is
similar to that observed on other large plateaus in the oceans. In addition, a 550,000 sq km aeromagnetic survey was flown over the section of the Alpha and Lomonosov ridges adjacent to North America and Greenland. The survey comprises of a set of
800 km long flight lines, spaced 12-15 km apart, subparallel to the Lomonosov Ridge. We present the results of aeromagnetic data compiled from the new LOMGRAV survey and reprocessed NRL-98/-99 data. The combined magnetic and seismic refraction data
provide hitherto undetected tectonic links between the HALIP and the Alpha Ridge that serve as important constraints on the plate tectonic setting and history. |
| GEOSCAN ID | 315335 |
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