Ground‐penetrating radar study of Pleistocene ice scours on a glaciolacustrine sequence boundary
Ice scouring of lake and sea‐floor substrates by the keels of drifting ice masses is a common geological process in modern northern lakes and continental shelves, and was widespread during the Pleistocene. Nonetheless, the importance of scouring as a geological process is not yet matched by many sed...
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crwiley:10.1111/j.1502-3885.2008.00024.x 2024-06-02T08:04:14+00:00 Ground‐penetrating radar study of Pleistocene ice scours on a glaciolacustrine sequence boundary EYLES, NICK MEULENDYK, THOMAS 2008 http://dx.doi.org/10.1111/j.1502-3885.2008.00024.x https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1111%2Fj.1502-3885.2008.00024.x https://onlinelibrary.wiley.com/doi/pdf/10.1111/j.1502-3885.2008.00024.x en eng Wiley http://onlinelibrary.wiley.com/termsAndConditions#vor Boreas volume 37, issue 2, page 226-233 ISSN 0300-9483 1502-3885 journal-article 2008 crwiley https://doi.org/10.1111/j.1502-3885.2008.00024.x 2024-05-03T10:43:36Z Ice scouring of lake and sea‐floor substrates by the keels of drifting ice masses is a common geological process in modern northern lakes and continental shelves, and was widespread during the Pleistocene. Nonetheless, the importance of scouring as a geological process is not yet matched by many sedimentological studies of scour structures exposed in outcrop. This article presents an integrated study combining outcrop sedimentology and subsurface ground‐penetrating radar (GPR) data from a relict late Pleistocene ice‐scoured glacial lake floor now preserved below beach sediments in Ontario, Canada. Scours occur along a regressive sequence boundary where deep‐water muddy facies are abruptly overlain by shallow‐water sands resulting from an abrupt drop in water levels. This has allowed the keels of drifting ice masses to scour into muds. Three‐dimensional data gained from the GPR survey show that scours are as much as 2.5 m deep and 7 m wide; they have berms of displaced sediment and are oriented parallel to the former shoreline. Scoured shoreface sediments that fill scours show abundant liquefaction structures, indicating substrate dewatering during repeated scouring events similar to that recently reported in the modern Beaufort Sea in Canada's far north. Marked changes in water depths are typical of glacially influenced lakes and seas, creating opportunities for drifting ice to scour into offshore muddy cohesive facies and be preserved. The data presented here may aid identification in ancient successions elsewhere. Article in Journal/Newspaper Beaufort Sea Wiley Online Library Canada Glacial Lake ENVELOPE(-129.463,-129.463,58.259,58.259) Boreas 37 2 226 233 |
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Open Polar |
collection |
Wiley Online Library |
op_collection_id |
crwiley |
language |
English |
description |
Ice scouring of lake and sea‐floor substrates by the keels of drifting ice masses is a common geological process in modern northern lakes and continental shelves, and was widespread during the Pleistocene. Nonetheless, the importance of scouring as a geological process is not yet matched by many sedimentological studies of scour structures exposed in outcrop. This article presents an integrated study combining outcrop sedimentology and subsurface ground‐penetrating radar (GPR) data from a relict late Pleistocene ice‐scoured glacial lake floor now preserved below beach sediments in Ontario, Canada. Scours occur along a regressive sequence boundary where deep‐water muddy facies are abruptly overlain by shallow‐water sands resulting from an abrupt drop in water levels. This has allowed the keels of drifting ice masses to scour into muds. Three‐dimensional data gained from the GPR survey show that scours are as much as 2.5 m deep and 7 m wide; they have berms of displaced sediment and are oriented parallel to the former shoreline. Scoured shoreface sediments that fill scours show abundant liquefaction structures, indicating substrate dewatering during repeated scouring events similar to that recently reported in the modern Beaufort Sea in Canada's far north. Marked changes in water depths are typical of glacially influenced lakes and seas, creating opportunities for drifting ice to scour into offshore muddy cohesive facies and be preserved. The data presented here may aid identification in ancient successions elsewhere. |
format |
Article in Journal/Newspaper |
author |
EYLES, NICK MEULENDYK, THOMAS |
spellingShingle |
EYLES, NICK MEULENDYK, THOMAS Ground‐penetrating radar study of Pleistocene ice scours on a glaciolacustrine sequence boundary |
author_facet |
EYLES, NICK MEULENDYK, THOMAS |
author_sort |
EYLES, NICK |
title |
Ground‐penetrating radar study of Pleistocene ice scours on a glaciolacustrine sequence boundary |
title_short |
Ground‐penetrating radar study of Pleistocene ice scours on a glaciolacustrine sequence boundary |
title_full |
Ground‐penetrating radar study of Pleistocene ice scours on a glaciolacustrine sequence boundary |
title_fullStr |
Ground‐penetrating radar study of Pleistocene ice scours on a glaciolacustrine sequence boundary |
title_full_unstemmed |
Ground‐penetrating radar study of Pleistocene ice scours on a glaciolacustrine sequence boundary |
title_sort |
ground‐penetrating radar study of pleistocene ice scours on a glaciolacustrine sequence boundary |
publisher |
Wiley |
publishDate |
2008 |
url |
http://dx.doi.org/10.1111/j.1502-3885.2008.00024.x https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1111%2Fj.1502-3885.2008.00024.x https://onlinelibrary.wiley.com/doi/pdf/10.1111/j.1502-3885.2008.00024.x |
long_lat |
ENVELOPE(-129.463,-129.463,58.259,58.259) |
geographic |
Canada Glacial Lake |
geographic_facet |
Canada Glacial Lake |
genre |
Beaufort Sea |
genre_facet |
Beaufort Sea |
op_source |
Boreas volume 37, issue 2, page 226-233 ISSN 0300-9483 1502-3885 |
op_rights |
http://onlinelibrary.wiley.com/termsAndConditions#vor |
op_doi |
https://doi.org/10.1111/j.1502-3885.2008.00024.x |
container_title |
Boreas |
container_volume |
37 |
container_issue |
2 |
container_start_page |
226 |
op_container_end_page |
233 |
_version_ |
1800748860675457024 |