Titre | Flemish Cap: a unique part of the Canadian continental shelf |
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Auteur | Piper, D J W |
Source | Atlantic Geoscience Society, abstracts, 44th Colloquium and Annual General Meeting 2018; Atlantic Geology vol. 54, 2018 p. 113-114 |
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Année | 2018 |
Séries alt. | Ressources naturelles Canada, Contribution externe 20170340 |
Éditeur | Société géoscientifique de l'Atlantique |
Réunion | 44th Colloquium and Annual General Meeting 2018; Truro, NS; CA; février 2-3, 2018 |
Document | publication en série |
Lang. | anglais |
Media | papier; en ligne; numérique |
Formats | pdf |
Province | Région extracotière de l'est; Terre-Neuve-et-Labrador |
Région | Flemish Cap |
Lat/Long OENS | -47.0000 -43.0000 49.0000 46.0000 |
Sujets | marges continentales; plate-forme continentale; caractéristiques sous-marines; géologie du socle; caractéristiques structurales; horsts; antécédents géologiques; antecedents glaciaires; glaciation;
sédimentation; interprétations géophysiques; interpretations sismiques; bathymétrie; sédiments marins; dépôts glaciaires; tills; coins de till; marges glaciaires; courants de turbidite; glissements de terrain; glissements de pentes; présence de
pétrole; pressions interstitielles; secousses séismiques; Avalonie; Calotte glaciaire; géologie marine; géologie des dépôts meubles/géomorphologie; géophysique; combustibles fossiles; Phanérozoïque; Cénozoïque; Mésozoïque; Paléozoïque |
Programme | Géoscience en mer |
Diffusé | 2018 02 01 |
Résumé | (disponible en anglais seulement) Flemish Cap is a triumph of Canadian diplomacy, being implicitly identified in Article 76 of the UN Convention on the Law of the Sea along with 'plateaux,
rises, banks and spurs'. It is also quite unusual in its Quaternary geology. Flemish Cap is a horst of Avalonian basement rocks with a thin Mesozoic and Cenozoic cover, separated from the Grand Banks by the 1000 m deep Flemish Pass. The flanks of the
Cap are one of the few areas on the eastern Canadian margin to show neotectonic features. Flemish Cap appears to have supported a glacial ice cap during the penultimate glaciation (MIS 6) despite being no shallower than 127 m today. Seismic profiles
show features interpreted as grounding line wedges (“till tongues”) and multibeam bathymetry shows upper slope iceberg pits - evidence of indurated substrate. Ice-margin gullies dating from MIS 6 are widespread around Flemish Cap; a few have been
reactivated by turbidity current flows off the Cap. Since MIS 6, sediment supply to the Cap has been almost entirely by iceberg rafting. Sands and gravels have been segregated by currents, with sands swept up into large sand ridges, probably at times
of lowered sea level. Large muddy sediment drifts have accumulated in deeper waters around Flemish Cap and cores from these drifts preserve a record of sediment supply from the Labrador Current over the last glacial cycle and into the Holocene.
Occasional slope failures in these drifts are likely preconditioned by escaping hydrocarbon fluids, resulting in excess pore pressure, and were triggered by rare passive margin earthquakes. The differences between Flemish Cap and other outer shelf
areas on the eastern Canadian margin help to unravel the relative importance of different sedimentation processes on a regional scale. This synthesis draws on collaborative work, some unpublished, with the Nereida program, Cooper Stacey, Lara
Miles, Longjiang Mao, Georgia Pe-Piper, Sabrina Korsmann, Calvin Campbell, Gordon Cameron, Kevin MacKillop and Nicole Rudolph. |
Sommaire | (Résumé en langage clair et simple, non publié) Présentation de la conférence orale résumant la géologie du Quaternaire du Bonnet Flamand |
GEOSCAN ID | 306498 |
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