| Title | Flemish Cap: a unique part of the Canadian continental shelf |
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| Author | Piper, D J W |
| Source | Atlantic Geoscience Society, abstracts, 44th Colloquium and Annual General Meeting 2018; Atlantic Geology vol. 54, 2018 p. 113-114 |
| Image |  |
| Year | 2018 |
| Alt Series | Natural Resources Canada, Contribution Series 20170340 |
| Publisher | Atlantic Geoscience Society |
| Meeting | 44th Colloquium and Annual General Meeting 2018; Truro, NS; CA; February 2-3, 2018 |
| Document | serial |
| Lang. | English |
| Media | paper; on-line; digital |
| File format | pdf |
| Province | Eastern offshore region; Newfoundland and Labrador |
| Area | Flemish Cap |
| Lat/Long WENS | -47.0000 -43.0000 49.0000 46.0000 |
| Subjects | marine geology; surficial geology/geomorphology; geophysics; fossil fuels; continental margins; continental shelf; submarine features; basement geology; structural features; horsts; geological history;
glacial history; glaciation; sedimentation; geophysical interpretations; seismic interpretations; bathymetry; marine sediments; glacial deposits; tills; till wedges; ice margins; turbidity currents; landslides; slope failures; petroleum occurrence;
pore pressures; earthquakes; Avalonia; Ice caps; Phanerozoic; Cenozoic; Mesozoic; Paleozoic |
| Program | Offshore Geoscience |
| Released | 2018 02 01 |
| Abstract | 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. |
| Summary | (Plain Language Summary, not published)
Oral conference presentation summarizing the Quaternary geology of Flemish Cap |
| GEOSCAN ID | 306498 |
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