New insights into the morphology, fill, and remarkable longevity (>0.2 m.y.) of modern deep-water erosional scours along the northeast Atlantic margin

A series of large-scale erosional scours are described from four modern deep-water canyon and/or channel systems along the northeast Atlantic continental margin. Regional-scale geophysical data indicate that most scours occur in zones of rapid flow expansion, such as canyon and/or channel termini an...

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Published in:Geosphere
Main Authors: Macdonald, H.A., Wynn, R.B., Huvenne, V.A.I., Peakall, J., Masson, D.G., Weaver, P.P.E., McPhail, S.D.
Format: Article in Journal/Newspaper
Language:unknown
Published: 2011
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Online Access:http://nora.nerc.ac.uk/id/eprint/295597/
https://doi.org/10.1130/GES00611.1
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spelling ftnerc:oai:nora.nerc.ac.uk:295597 2023-05-15T17:41:21+02:00 New insights into the morphology, fill, and remarkable longevity (>0.2 m.y.) of modern deep-water erosional scours along the northeast Atlantic margin Macdonald, H.A. Wynn, R.B. Huvenne, V.A.I. Peakall, J. Masson, D.G. Weaver, P.P.E. McPhail, S.D. 2011-08 http://nora.nerc.ac.uk/id/eprint/295597/ https://doi.org/10.1130/GES00611.1 unknown Macdonald, H.A.; Wynn, R.B.; Huvenne, V.A.I. orcid:0000-0001-7135-6360 Peakall, J.; Masson, D.G.; Weaver, P.P.E.; McPhail, S.D. 2011 New insights into the morphology, fill, and remarkable longevity (>0.2 m.y.) of modern deep-water erosional scours along the northeast Atlantic margin. Geosphere, 7 (4). 845-867. https://doi.org/10.1130/GES00611.1 <https://doi.org/10.1130/GES00611.1> Publication - Article PeerReviewed 2011 ftnerc https://doi.org/10.1130/GES00611.1 2023-02-04T19:35:53Z A series of large-scale erosional scours are described from four modern deep-water canyon and/or channel systems along the northeast Atlantic continental margin. Regional-scale geophysical data indicate that most scours occur in zones of rapid flow expansion, such as canyon and/or channel termini and margins. High-resolution images of the scours cover ∼25 km² at 2 × 2 m pixel size, and were obtained at depths of 4200–4900 m using Autosub6000, an autonomous underwater vehicle equipped with an EM2000 multibeam bathymetry system. Sedimentological and microfossil-based chronological data of scour fills and interscour areas were obtained via accurately located piston cores that targeted specific sites within imaged areas. These core data reveal a number of key findings. (1) Deep-water scours can be very long lived (>0.2 m.y. ) and may undergo discrete phases of isolation, amalgamation, and infilling. (2) Deep-water scours can develop via a composite of cutting and filling events with periodicities of between tens of thousands and hundreds of thousands of years. (3) Immediately adjacent scours may have strikingly different sedimentological histories and do not necessarily evolve contemporaneously. (4) Scour infills are typically out of phase with sedimentation in intrascour areas, having thin sands internally and thick sands externally, or thick muds internally and thin muds externally. (5) Erosional hiatuses within scour fills may represent hundreds of thousands of years of time, and yet leave little visible record. Four distinct morphologies of scour are identified that range from 40 to 3170 m wide and 8 to 48 m deep: spoon shaped, heel shaped, crescent shaped, and oval shaped. Isolated scours are shown to coalesce laterally into broad regions of amalgamated scour that may be several kilometers across. The combined morphosedimentological data set is used to examine some of the putative formative mechanisms for scour genesis. Article in Journal/Newspaper Northeast Atlantic Natural Environment Research Council: NERC Open Research Archive Geosphere 7 4 845 867
institution Open Polar
collection Natural Environment Research Council: NERC Open Research Archive
op_collection_id ftnerc
language unknown
description A series of large-scale erosional scours are described from four modern deep-water canyon and/or channel systems along the northeast Atlantic continental margin. Regional-scale geophysical data indicate that most scours occur in zones of rapid flow expansion, such as canyon and/or channel termini and margins. High-resolution images of the scours cover ∼25 km² at 2 × 2 m pixel size, and were obtained at depths of 4200–4900 m using Autosub6000, an autonomous underwater vehicle equipped with an EM2000 multibeam bathymetry system. Sedimentological and microfossil-based chronological data of scour fills and interscour areas were obtained via accurately located piston cores that targeted specific sites within imaged areas. These core data reveal a number of key findings. (1) Deep-water scours can be very long lived (>0.2 m.y. ) and may undergo discrete phases of isolation, amalgamation, and infilling. (2) Deep-water scours can develop via a composite of cutting and filling events with periodicities of between tens of thousands and hundreds of thousands of years. (3) Immediately adjacent scours may have strikingly different sedimentological histories and do not necessarily evolve contemporaneously. (4) Scour infills are typically out of phase with sedimentation in intrascour areas, having thin sands internally and thick sands externally, or thick muds internally and thin muds externally. (5) Erosional hiatuses within scour fills may represent hundreds of thousands of years of time, and yet leave little visible record. Four distinct morphologies of scour are identified that range from 40 to 3170 m wide and 8 to 48 m deep: spoon shaped, heel shaped, crescent shaped, and oval shaped. Isolated scours are shown to coalesce laterally into broad regions of amalgamated scour that may be several kilometers across. The combined morphosedimentological data set is used to examine some of the putative formative mechanisms for scour genesis.
format Article in Journal/Newspaper
author Macdonald, H.A.
Wynn, R.B.
Huvenne, V.A.I.
Peakall, J.
Masson, D.G.
Weaver, P.P.E.
McPhail, S.D.
spellingShingle Macdonald, H.A.
Wynn, R.B.
Huvenne, V.A.I.
Peakall, J.
Masson, D.G.
Weaver, P.P.E.
McPhail, S.D.
New insights into the morphology, fill, and remarkable longevity (>0.2 m.y.) of modern deep-water erosional scours along the northeast Atlantic margin
author_facet Macdonald, H.A.
Wynn, R.B.
Huvenne, V.A.I.
Peakall, J.
Masson, D.G.
Weaver, P.P.E.
McPhail, S.D.
author_sort Macdonald, H.A.
title New insights into the morphology, fill, and remarkable longevity (>0.2 m.y.) of modern deep-water erosional scours along the northeast Atlantic margin
title_short New insights into the morphology, fill, and remarkable longevity (>0.2 m.y.) of modern deep-water erosional scours along the northeast Atlantic margin
title_full New insights into the morphology, fill, and remarkable longevity (>0.2 m.y.) of modern deep-water erosional scours along the northeast Atlantic margin
title_fullStr New insights into the morphology, fill, and remarkable longevity (>0.2 m.y.) of modern deep-water erosional scours along the northeast Atlantic margin
title_full_unstemmed New insights into the morphology, fill, and remarkable longevity (>0.2 m.y.) of modern deep-water erosional scours along the northeast Atlantic margin
title_sort new insights into the morphology, fill, and remarkable longevity (>0.2 m.y.) of modern deep-water erosional scours along the northeast atlantic margin
publishDate 2011
url http://nora.nerc.ac.uk/id/eprint/295597/
https://doi.org/10.1130/GES00611.1
genre Northeast Atlantic
genre_facet Northeast Atlantic
op_relation Macdonald, H.A.; Wynn, R.B.; Huvenne, V.A.I. orcid:0000-0001-7135-6360
Peakall, J.; Masson, D.G.; Weaver, P.P.E.; McPhail, S.D. 2011 New insights into the morphology, fill, and remarkable longevity (>0.2 m.y.) of modern deep-water erosional scours along the northeast Atlantic margin. Geosphere, 7 (4). 845-867. https://doi.org/10.1130/GES00611.1 <https://doi.org/10.1130/GES00611.1>
op_doi https://doi.org/10.1130/GES00611.1
container_title Geosphere
container_volume 7
container_issue 4
container_start_page 845
op_container_end_page 867
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