GEOSCAN, résultats de la recherche


TitreInsight into the glacial history of the Bay of Fundy revealed through sea floor mapping using multibeam sonar
AuteurTodd, B J; Shaw, J; Parrott, D R; Kostylev, V E
SourceResource development and its implications in the Bay of Fundy and Gulf of Maine : 8th BoFEP Bay of Fundy Science Workshop, book of abstracts; par Bay of Fundy Ecosystem Partnership; 2009 p. 1
LiensOnline - En ligne
LiensThe 8th BoFEP Bay of Fundy Science Workshop
Séries alt.Secteur des sciences de la Terre, Contribution externe 20080625
Réunion8th BoFEP Bay of Fundy Science Workshop; Wolfville; CA; mai 26-29, 2009
Medianumérique; en ligne
ProvinceRégion extracotière de l'est
Lat/Long OENS-67.5000 -64.5000 45.5000 44.2500
Sujetsantecedents glaciaires; dépôts glaciaires; topographie glaciaire; topographie du fond océanique; topographie du fond océanique; drumlins; mégacannelures; géologie des dépôts meubles/géomorphologie; géologie marine; géophysique; Cénozoïque; Quaternaire
ProgrammeLes géosciences à l'appui de la gestion des océans
Résumé(disponible en anglais seulement)
In 2006, the Geological Survey of Canada, in cooperation with the Canadian Hydrographic Service and the University of New Brunswick, instituted a broad-scale regional mapping program to map the entire sea floor of the Bay of Fundy. To date, 12,466 square kilometres of multibeam sonar coverage have been acquired. The resulting sea floor map contains a wealth of evidence demonstrating the impact of Pleistocene Epoch glaciation on the Bay of Fundy and holds the promise of yielding one of the most comprehensive depictions of a glacial landsystem ever obtained in a marine setting. Glacial ice flowed from the head of the bay in the northeast to the Gulf of Maine in the southwest. In the southwest, a topographically controlled ice stream existed in the bedrock trough between Brier and Grand Manan islands. Streamlined subglacial landforms (drumlins and megaflutes) are prominent on the flanks of the trough. Prominent lobate ridges, convex to the southwest, are ubiquitous in the central portion of the bay. It is not clear if these ridges are subglacial or ice-front in origin; in any case they appear to mark a complex pattern of ice retreat to the northeast. During retreat, icebergs calved from the floating ice front; iceberg keels incised a dense pattern of scours and pits into the sea floor sediment and this pattern is used to infer paleocurrent patterns. Superimposed on the glacial landsystem features are Holocene Epoch sedimentary bedforms that reflect the modern current regime in the Bay of Fundy.