GEOSCAN, résultats de la recherche


TitreGlacial flute marks and iceberg scours inscribed on the seabed in Peel Sound, Franklin Strait, Larsen Sound and M'Clintock Channel, Canadian Arctic Archipelago
AuteurMacLean, B; Blasco, S; Bennett, R; Rainey, W; Hughes-Clarke, J; Beaudoin, J
SourceArctic Change 2008, Conference program and abstracts/Arctic Change 2008, Programmes et résumés de la conférence; 2008 p. 267-268
LiensArctic Change 2008
Séries alt.Secteur des sciences de la Terre, Contribution externe 20080394
RéunionArctic Change Conference; Quebec City; CA; décembre 9-12, 2008
ProvinceRégion extracotière du nord
SNRC67E; 67F; 67G; 67H; 68A; 68B; 68C; 68D
Lat/Long OENS-104.0000 -95.0000 75.0000 70.0000
Sujetsrainures glaciaires; affouillements glaciaires; affouillement; géologie des dépôts meubles/géomorphologie; géologie marine; Quaternaire
Résumé(disponible en anglais seulement)
The study area lies within the central part of the Canadian Arctic Archipelago; a region that was covered by Laurentide ice during the Late Wisconsinan and earlier. Multibeam imagery from widely spaced transects indicates the presence of both parallel - sub-parallel ice keel features and randomly oriented iceberg scours on the seabed at localities in Peel Sound, Franklin Strait, northern Larsen Sound, and in M'Clintock Channel. Linear parallel - sub-parallel groove and ridge features are interpreted to be sole marks emplaced on the seabed by ice streams that formerly occupied these marine areas. These features have been observed on multibeam imagery at various localities along the channels, and are especially well developed in an overdeepened area at the junction of Franklin Strait and Peel Sound. The trend of these features is parallel to the axes and coastlines of the channels. Their north-south orientation in Peel Sound is normal to that of glacial ice flow features on Somerset and eastern Prince of Wales islands, which border Peel Sound to the east and west, respectively. The seabed in many areas also displays scours formed by grounding icebergs. These are primarily single keel features. Maximum iceberg grounding depths are variable relative to present day water depths. Ice stream sole mark features in water depths deeper than 350 m in the overdeepened area in Peel Sound have not been impacted by grounding icebergs. Above 350 m, iceberg scours of variable orientations increase in number and decrease in size as depths shallow. However, in the southern M'Clintock Channel - Larsen Sound area, apparently unmodified parallel - sub-parallel ice keel features occur in depths as shallow as 145 m. Seabed sediments revealed by 3.5 kHz sub-bottom profiles are interpreted to consist primarily of ice-contact deposits that in a few localities are draped by later sediments. The age of the ice stream features has not been established. Their formation was possibly coincident with an ice stream in the M'Clintock Channel - Victoria Island region, which formed an ice shelf in Viscount Melville Sound that grounded on southern Melville and Byam Martin islands at ca. 10.4 - 9.6 ka. Or they could have resulted from later glacial events. The iceberg scours are also inferred to be principally relict features.