Early Holocene sea level in the Canadian Beaufort Sea constrained by radiocarbon dates from a deep borehole in the Mackenzie Trough, Arctic Canada
Deglacial and Holocene relative sea level ( RSL ) in the Canadian Beaufort Sea was influenced by the timing and extent of glacial ice in the Mackenzie River corridor and adjacent coastal plains. Considerable evidence indicates extensive ice cover in this region of northwestern Canada during the Late...
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crwiley:10.1111/bor.12335 2024-06-02T08:02:47+00:00 Early Holocene sea level in the Canadian Beaufort Sea constrained by radiocarbon dates from a deep borehole in the Mackenzie Trough, Arctic Canada O'Regan, Matt Coxall, Helen Hill, Philip Hilton, Robert Muschitiello, Francesco Swärd, Henrik Vetenskapsrådet Natural Environment Research Council British Society for Geomorphology 2018 http://dx.doi.org/10.1111/bor.12335 https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1111%2Fbor.12335 https://onlinelibrary.wiley.com/doi/pdf/10.1111/bor.12335 en eng Wiley http://onlinelibrary.wiley.com/termsAndConditions#vor Boreas volume 47, issue 4, page 1102-1117 ISSN 0300-9483 1502-3885 journal-article 2018 crwiley https://doi.org/10.1111/bor.12335 2024-05-03T10:48:26Z Deglacial and Holocene relative sea level ( RSL ) in the Canadian Beaufort Sea was influenced by the timing and extent of glacial ice in the Mackenzie River corridor and adjacent coastal plains. Considerable evidence indicates extensive ice cover in this region of northwestern Canada during the Late Wisconsinan. However, no absolute ages exist to constrain maximum RSL lowering before the late Holocene (4.2–0 ka). In 1984, the Geological Survey of Canada drilled an 81.5‐m‐deep borehole in the western Mackenzie Trough at 45 m water depth ( MTW 01). The lower 52.5 m of the borehole was interpreted as a deltaic progradational sequence deposited during a period of rising sea level. The upper 29 m was described as foraminifer‐bearing marine sediments deposited after transgression of the site, when RSL rose above ~−74 m. Here, we present radiocarbon measurements from MTW 01, acquired from benthic foraminifera, mollusc fragments and particulate organic carbon in the >63 μm fraction ( POC >63 μm ) in an attempt to constrain the chronology of sediments within this borehole and date the timing of transgression. The deepest carbonate macrofossil was acquired from 8 m above the transgressive surface (equivalent to 21 m b.s.l.), where mollusc fragments returned a date of 9400 +180–260 cal. a BP (2σ). This provides the oldest constraint on Holocene sea‐level lowering in the region, and implies that transgression at this site occurred prior to the early Holocene. Ages obtained from the lower 52.5 m of the borehole are limited to POC >63 μm samples. These indicate that progradational sediments were deposited rapidly after 24 820 +390–380 cal. a BP (2σ). Due to the incorporation of older reworked organic matter, the actual age of progradation is likely to be younger, occurring after Late Wisconsinan glacial ice retreated from the coast. Article in Journal/Newspaper Arctic Beaufort Sea Foraminifera* Mackenzie river Wiley Online Library Arctic Canada Mackenzie River MacKenzie Trough ENVELOPE(-138.025,-138.025,69.528,69.528) Boreas 47 4 1102 1117 |
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Open Polar |
collection |
Wiley Online Library |
op_collection_id |
crwiley |
language |
English |
description |
Deglacial and Holocene relative sea level ( RSL ) in the Canadian Beaufort Sea was influenced by the timing and extent of glacial ice in the Mackenzie River corridor and adjacent coastal plains. Considerable evidence indicates extensive ice cover in this region of northwestern Canada during the Late Wisconsinan. However, no absolute ages exist to constrain maximum RSL lowering before the late Holocene (4.2–0 ka). In 1984, the Geological Survey of Canada drilled an 81.5‐m‐deep borehole in the western Mackenzie Trough at 45 m water depth ( MTW 01). The lower 52.5 m of the borehole was interpreted as a deltaic progradational sequence deposited during a period of rising sea level. The upper 29 m was described as foraminifer‐bearing marine sediments deposited after transgression of the site, when RSL rose above ~−74 m. Here, we present radiocarbon measurements from MTW 01, acquired from benthic foraminifera, mollusc fragments and particulate organic carbon in the >63 μm fraction ( POC >63 μm ) in an attempt to constrain the chronology of sediments within this borehole and date the timing of transgression. The deepest carbonate macrofossil was acquired from 8 m above the transgressive surface (equivalent to 21 m b.s.l.), where mollusc fragments returned a date of 9400 +180–260 cal. a BP (2σ). This provides the oldest constraint on Holocene sea‐level lowering in the region, and implies that transgression at this site occurred prior to the early Holocene. Ages obtained from the lower 52.5 m of the borehole are limited to POC >63 μm samples. These indicate that progradational sediments were deposited rapidly after 24 820 +390–380 cal. a BP (2σ). Due to the incorporation of older reworked organic matter, the actual age of progradation is likely to be younger, occurring after Late Wisconsinan glacial ice retreated from the coast. |
author2 |
Vetenskapsrådet Natural Environment Research Council British Society for Geomorphology |
format |
Article in Journal/Newspaper |
author |
O'Regan, Matt Coxall, Helen Hill, Philip Hilton, Robert Muschitiello, Francesco Swärd, Henrik |
spellingShingle |
O'Regan, Matt Coxall, Helen Hill, Philip Hilton, Robert Muschitiello, Francesco Swärd, Henrik Early Holocene sea level in the Canadian Beaufort Sea constrained by radiocarbon dates from a deep borehole in the Mackenzie Trough, Arctic Canada |
author_facet |
O'Regan, Matt Coxall, Helen Hill, Philip Hilton, Robert Muschitiello, Francesco Swärd, Henrik |
author_sort |
O'Regan, Matt |
title |
Early Holocene sea level in the Canadian Beaufort Sea constrained by radiocarbon dates from a deep borehole in the Mackenzie Trough, Arctic Canada |
title_short |
Early Holocene sea level in the Canadian Beaufort Sea constrained by radiocarbon dates from a deep borehole in the Mackenzie Trough, Arctic Canada |
title_full |
Early Holocene sea level in the Canadian Beaufort Sea constrained by radiocarbon dates from a deep borehole in the Mackenzie Trough, Arctic Canada |
title_fullStr |
Early Holocene sea level in the Canadian Beaufort Sea constrained by radiocarbon dates from a deep borehole in the Mackenzie Trough, Arctic Canada |
title_full_unstemmed |
Early Holocene sea level in the Canadian Beaufort Sea constrained by radiocarbon dates from a deep borehole in the Mackenzie Trough, Arctic Canada |
title_sort |
early holocene sea level in the canadian beaufort sea constrained by radiocarbon dates from a deep borehole in the mackenzie trough, arctic canada |
publisher |
Wiley |
publishDate |
2018 |
url |
http://dx.doi.org/10.1111/bor.12335 https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1111%2Fbor.12335 https://onlinelibrary.wiley.com/doi/pdf/10.1111/bor.12335 |
long_lat |
ENVELOPE(-138.025,-138.025,69.528,69.528) |
geographic |
Arctic Canada Mackenzie River MacKenzie Trough |
geographic_facet |
Arctic Canada Mackenzie River MacKenzie Trough |
genre |
Arctic Beaufort Sea Foraminifera* Mackenzie river |
genre_facet |
Arctic Beaufort Sea Foraminifera* Mackenzie river |
op_source |
Boreas volume 47, issue 4, page 1102-1117 ISSN 0300-9483 1502-3885 |
op_rights |
http://onlinelibrary.wiley.com/termsAndConditions#vor |
op_doi |
https://doi.org/10.1111/bor.12335 |
container_title |
Boreas |
container_volume |
47 |
container_issue |
4 |
container_start_page |
1102 |
op_container_end_page |
1117 |
_version_ |
1800747252338130944 |