| Titre | Sedimentary and crustal structure from the Ellesmere Island and Greenland continental shelves onto the Lomonosov Ridge, Arctic Ocean |
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| Auteur | Jackson, H R ;
Dahl-Jensen, T; Chian, D; Shimeld, J; Funck, T; Asudeh, I; Snyder, D |
| Source | Geophysical Journal International vol. 182, issue 1, 2010 p. 11-35, https://doi.org/10.1111/j.1365-246X.2010.04604.x |
| Image |  |
| Année | 2010 |
| Séries alt. | Secteur des sciences de la Terre, Contribution externe 20090300 |
| Éditeur | Oxford University Press (OUP) |
| Document | publication en série |
| Lang. | anglais |
| DOI | https://doi.org/10.1111/j.1365-246X.2010.04604.x |
| Media | papier; en ligne; numérique |
| Formats | pdf |
| Province | Région extracotière du nord |
| SNRC | 120; 340; 560 |
| Région | Lomonosov Ridge; île d'Ellesmere |
| Lat/Long OENS | -100.0000 -40.0000 86.0000 80.0000 |
| Sujets | levés géophysiques; anomalies magnétiques; anomalies de bouguer; marges continentales; vitesse des ondes sismiques; modèles de la pesanteur; interprétations de la pesanteur; interprétations tectoniques;
géophysique; tectonique |
| Illustrations | croquis cartographiques |
| Programme | Délimitation du plateau continental du Canada en vertu de la Convention des Nations Unies sur le droit de la mer (UNCLOS) |
| Diffusé | 2010 04 01 |
| Résumé | (disponible en anglais seulement)
On the northern passive margin of Ellesmere Island and Greenland, two long wide-angle seismic reflection/refraction (WAR) profiles and a short vertical incident
reflection profile were acquired. The WAR seismic source was explosives and the receivers were vertical geophones placed on the sea ice. A 440 km long North-South profile that crossed the shelf, a bathymetric trough and onto the Lomonosov Ridge was
completed. In addition, a 110 km long profile along the trough was completed. P-wave velocity models were created by forward and inverse modelling. On the shelf modelling indicates a 12 km deep sedimentary basin consisting of three layers with
velocities of 2.1-2.2, 3.1-3.2 and 4.3-5.2 km s-1. Between the 3.1-3.2 km s-1 and 4.3-5.2 km s-1 layers there is a velocity discontinuity that dips seaward, consistent with a regional unconformity. The 4.3-5.2 km s-1 layer is interpreted to be
Palaeozoic to Mesozoic age strata, based on local and regional geological constraints. Beneath these layers, velocities of 5.4-5.9 km s-1 are correlated with metasedimentary rocks that outcrop along the coast. These four layers continue from the
shelf onto the Lomonosov Ridge. On the Ridge, the bathymetric contours define a plateau 220 km across. The plateau is a basement high, confirmed by short reflection profiles and the velocities of 5.9-6.5 km s-1. Radial magnetic anomalies emanate from
the plateau indicating the volcanic nature of this feature. A lower crustal velocity of 6.2-6.7 km s-1, within the range identified on the Lomonosov Ridge near the Pole and typical of rifted continental crust, is interpreted along the entire line.
The Moho, based on the WAR data, has significant relief from 17 to 27 km that is confirmed by gravity modelling and consistent with the regional tectonics. In the trough, Moho shallows eastward from a maximum depth of 19-16 km. No indication of
oceanic crust was found in the bathymetric trough. |
| GEOSCAN ID | 248221 |
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