Shingled Quaternary debris flow lenses on the north‐east Newfoundland Slope
ABSTRACT Debris flow deposits are the principal component of Quaternary continental slope sediments between the north‐east Newfoundland Shelf and central Orphan Basin. In seismic profiles, these deposits occur as shingled, elongate, acoustically transparent lenses with their long axes orientated dow...
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Online Access: | http://dx.doi.org/10.1111/j.1365-3091.1992.tb01034.x https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1111%2Fj.1365-3091.1992.tb01034.x https://onlinelibrary.wiley.com/doi/pdf/10.1111/j.1365-3091.1992.tb01034.x |
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crwiley:10.1111/j.1365-3091.1992.tb01034.x 2024-09-15T18:12:31+00:00 Shingled Quaternary debris flow lenses on the north‐east Newfoundland Slope AKSU, A. E. HISCOTT, R. N. 1992 http://dx.doi.org/10.1111/j.1365-3091.1992.tb01034.x https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1111%2Fj.1365-3091.1992.tb01034.x https://onlinelibrary.wiley.com/doi/pdf/10.1111/j.1365-3091.1992.tb01034.x en eng Wiley http://onlinelibrary.wiley.com/termsAndConditions#vor Sedimentology volume 39, issue 2, page 193-206 ISSN 0037-0746 1365-3091 journal-article 1992 crwiley https://doi.org/10.1111/j.1365-3091.1992.tb01034.x 2024-07-25T04:21:53Z ABSTRACT Debris flow deposits are the principal component of Quaternary continental slope sediments between the north‐east Newfoundland Shelf and central Orphan Basin. In seismic profiles, these deposits occur as shingled, elongate, acoustically transparent lenses with their long axes orientated downslope. Deposits of individual flows form positive mounds on the sea floor; subsequent flows were diverted by the pre‐existing topography into bathymetric lows between older debris flow deposits. These deposits show a large variation in the area of sea floor covered by individual flows (about 60–1000 km 2 ), average thickness of deposits (9–37 m) and volume of sediment displaced (1–27 km 3 ). The ratio of average thickness to a measure of deposit diameter, termed the aspect ratio, has a threefold variation from 0·0006 to 0·0021. Very low depositional slopes and low aspect ratios suggest relatively low viscosities, probably due to inmixing of water during downslope transport. Stratified sediments form three distinct horizons and are locally interbedded with the debris flow deposits. These are mainly hemipelagic deposits. The slope and rise to the west of the Orphan Basin are constructional in character. The apparent absence of upper slope erosional features and the abundance of debris flow deposits on the slope suggest that the supply of sediment to the continental slope occurred predominantly during times of maximum extent of Quaternary glacial ice. The ice sheet grounding line during several glacial maxima must have been situated at or near the present shelf break, supplying vast amounts of sediment directly to the upper slope. Oversteepening and subsequent slope failures fed material into deeper water. Article in Journal/Newspaper Ice Sheet Newfoundland Wiley Online Library Sedimentology 39 2 193 206 |
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Wiley Online Library |
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crwiley |
language |
English |
description |
ABSTRACT Debris flow deposits are the principal component of Quaternary continental slope sediments between the north‐east Newfoundland Shelf and central Orphan Basin. In seismic profiles, these deposits occur as shingled, elongate, acoustically transparent lenses with their long axes orientated downslope. Deposits of individual flows form positive mounds on the sea floor; subsequent flows were diverted by the pre‐existing topography into bathymetric lows between older debris flow deposits. These deposits show a large variation in the area of sea floor covered by individual flows (about 60–1000 km 2 ), average thickness of deposits (9–37 m) and volume of sediment displaced (1–27 km 3 ). The ratio of average thickness to a measure of deposit diameter, termed the aspect ratio, has a threefold variation from 0·0006 to 0·0021. Very low depositional slopes and low aspect ratios suggest relatively low viscosities, probably due to inmixing of water during downslope transport. Stratified sediments form three distinct horizons and are locally interbedded with the debris flow deposits. These are mainly hemipelagic deposits. The slope and rise to the west of the Orphan Basin are constructional in character. The apparent absence of upper slope erosional features and the abundance of debris flow deposits on the slope suggest that the supply of sediment to the continental slope occurred predominantly during times of maximum extent of Quaternary glacial ice. The ice sheet grounding line during several glacial maxima must have been situated at or near the present shelf break, supplying vast amounts of sediment directly to the upper slope. Oversteepening and subsequent slope failures fed material into deeper water. |
format |
Article in Journal/Newspaper |
author |
AKSU, A. E. HISCOTT, R. N. |
spellingShingle |
AKSU, A. E. HISCOTT, R. N. Shingled Quaternary debris flow lenses on the north‐east Newfoundland Slope |
author_facet |
AKSU, A. E. HISCOTT, R. N. |
author_sort |
AKSU, A. E. |
title |
Shingled Quaternary debris flow lenses on the north‐east Newfoundland Slope |
title_short |
Shingled Quaternary debris flow lenses on the north‐east Newfoundland Slope |
title_full |
Shingled Quaternary debris flow lenses on the north‐east Newfoundland Slope |
title_fullStr |
Shingled Quaternary debris flow lenses on the north‐east Newfoundland Slope |
title_full_unstemmed |
Shingled Quaternary debris flow lenses on the north‐east Newfoundland Slope |
title_sort |
shingled quaternary debris flow lenses on the north‐east newfoundland slope |
publisher |
Wiley |
publishDate |
1992 |
url |
http://dx.doi.org/10.1111/j.1365-3091.1992.tb01034.x https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1111%2Fj.1365-3091.1992.tb01034.x https://onlinelibrary.wiley.com/doi/pdf/10.1111/j.1365-3091.1992.tb01034.x |
genre |
Ice Sheet Newfoundland |
genre_facet |
Ice Sheet Newfoundland |
op_source |
Sedimentology volume 39, issue 2, page 193-206 ISSN 0037-0746 1365-3091 |
op_rights |
http://onlinelibrary.wiley.com/termsAndConditions#vor |
op_doi |
https://doi.org/10.1111/j.1365-3091.1992.tb01034.x |
container_title |
Sedimentology |
container_volume |
39 |
container_issue |
2 |
container_start_page |
193 |
op_container_end_page |
206 |
_version_ |
1810450096644423680 |