Marine Molluscs as Indicators of Environmental Change in Glaciated North America and Greenland During the Last 18 000 Years
Dated mollusc collections are classified in assemblages to map paleo-faunistic zones. Hiatella arctica and Mya truncata account for almost half the records and comprise a restricted arctic assemblage. Arctic assemblages comprise 70% and arctic-dominated assemblages 80% of the database. Fifteen speci...
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1996
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fterudit:oai:erudit.org:033087ar 2023-05-15T14:37:38+02:00 Marine Molluscs as Indicators of Environmental Change in Glaciated North America and Greenland During the Last 18 000 Years Dyke, Arthur S. Dale, Janis E. McNeely, Roger N. 1996 http://id.erudit.org/iderudit/033087ar https://doi.org/10.7202/033087ar en eng Les Presses de l'Université de Montréal Érudit Géographie physique et Quaternaire vol. 50 no. 2 (1996) http://id.erudit.org/iderudit/033087ar doi:10.7202/033087ar Tous droits réservés © Les Presses de l'Université de Montréal, 1996 text 1996 fterudit https://doi.org/10.7202/033087ar 2022-09-24T23:13:48Z Dated mollusc collections are classified in assemblages to map paleo-faunistic zones. Hiatella arctica and Mya truncata account for almost half the records and comprise a restricted arctic assemblage. Arctic assemblages comprise 70% and arctic-dominated assemblages 80% of the database. Fifteen species dominate but 170 taxa are recorded. At last glacial maximum, the arctic zone extended from the Arctic Ocean to the Grand Banks. The boreal zone in the western Atlantic was compressed. The subarctic zone, which today dominates eastern Canada, was small. The boreal zone was extensive in the eastern Pacific where subarctic and arctic zones were compressed. Zones shifted northward during deglaciation and the arctic zone diversified when Bering Strait submerged 10.5-10.3 ka BP. Western Arctic molluscs during Younger Dryas time indicate shallow waters warmer than present. Major North Atlantic currents were established 9.5-9.0 ka BP. The subarctic zone extended to the head of Baffin Bay and a boreal zone became established in West Greenland 9-8 ka BP, with intensive changes about 8.5 ka BP. We relate the latter to the reduction of Mackenzie River discharge and in sea ice export to the North Atlantic as Laurentide ice withdrew from Mackenzie headwaters. The extended subarctic zone in Baffin Bay persisted until 3 ka BP and then retreated about 1000 km on the Canadian side. Boreal-subarctic molluscs in the Gulf of St. Lawrence before 9.5 ka BP derived from the glacial refugium. High boreal-subarctic molluscs farther north probably migrated from Europe. We postulate that the Labrador Current acts as a one-way valve for mollusc migrations at glacial-interglacial scales. Les mollusques datés provenant de plus de 3000 collections ont été classés en paléo-zones fauniques. Hiatella arctica et Mya truncata comptent pour près de la moitié des relevés et comprennent un assemblage restreint à l'Arctique. Les assemblages arctiques ou à dominance arctique comptent respectivement pour 70% et 80% de l'ensemble des données. Sur les 170 ... Text Arctic Arctic Ocean Arctique* Baffin Bay Baffin Bay Baffin Bering Strait Greenland Mackenzie river North Atlantic Sea ice Subarctic Érudit.org (Université Montréal) Arctic Arctic Ocean Baffin Bay Bering Strait Canada Greenland Mackenzie River Pacific Géographie physique et Quaternaire 50 2 125 184 |
institution |
Open Polar |
collection |
Érudit.org (Université Montréal) |
op_collection_id |
fterudit |
language |
English |
description |
Dated mollusc collections are classified in assemblages to map paleo-faunistic zones. Hiatella arctica and Mya truncata account for almost half the records and comprise a restricted arctic assemblage. Arctic assemblages comprise 70% and arctic-dominated assemblages 80% of the database. Fifteen species dominate but 170 taxa are recorded. At last glacial maximum, the arctic zone extended from the Arctic Ocean to the Grand Banks. The boreal zone in the western Atlantic was compressed. The subarctic zone, which today dominates eastern Canada, was small. The boreal zone was extensive in the eastern Pacific where subarctic and arctic zones were compressed. Zones shifted northward during deglaciation and the arctic zone diversified when Bering Strait submerged 10.5-10.3 ka BP. Western Arctic molluscs during Younger Dryas time indicate shallow waters warmer than present. Major North Atlantic currents were established 9.5-9.0 ka BP. The subarctic zone extended to the head of Baffin Bay and a boreal zone became established in West Greenland 9-8 ka BP, with intensive changes about 8.5 ka BP. We relate the latter to the reduction of Mackenzie River discharge and in sea ice export to the North Atlantic as Laurentide ice withdrew from Mackenzie headwaters. The extended subarctic zone in Baffin Bay persisted until 3 ka BP and then retreated about 1000 km on the Canadian side. Boreal-subarctic molluscs in the Gulf of St. Lawrence before 9.5 ka BP derived from the glacial refugium. High boreal-subarctic molluscs farther north probably migrated from Europe. We postulate that the Labrador Current acts as a one-way valve for mollusc migrations at glacial-interglacial scales. Les mollusques datés provenant de plus de 3000 collections ont été classés en paléo-zones fauniques. Hiatella arctica et Mya truncata comptent pour près de la moitié des relevés et comprennent un assemblage restreint à l'Arctique. Les assemblages arctiques ou à dominance arctique comptent respectivement pour 70% et 80% de l'ensemble des données. Sur les 170 ... |
format |
Text |
author |
Dyke, Arthur S. Dale, Janis E. McNeely, Roger N. |
spellingShingle |
Dyke, Arthur S. Dale, Janis E. McNeely, Roger N. Marine Molluscs as Indicators of Environmental Change in Glaciated North America and Greenland During the Last 18 000 Years |
author_facet |
Dyke, Arthur S. Dale, Janis E. McNeely, Roger N. |
author_sort |
Dyke, Arthur S. |
title |
Marine Molluscs as Indicators of Environmental Change in Glaciated North America and Greenland During the Last 18 000 Years |
title_short |
Marine Molluscs as Indicators of Environmental Change in Glaciated North America and Greenland During the Last 18 000 Years |
title_full |
Marine Molluscs as Indicators of Environmental Change in Glaciated North America and Greenland During the Last 18 000 Years |
title_fullStr |
Marine Molluscs as Indicators of Environmental Change in Glaciated North America and Greenland During the Last 18 000 Years |
title_full_unstemmed |
Marine Molluscs as Indicators of Environmental Change in Glaciated North America and Greenland During the Last 18 000 Years |
title_sort |
marine molluscs as indicators of environmental change in glaciated north america and greenland during the last 18 000 years |
publisher |
Les Presses de l'Université de Montréal |
publishDate |
1996 |
url |
http://id.erudit.org/iderudit/033087ar https://doi.org/10.7202/033087ar |
geographic |
Arctic Arctic Ocean Baffin Bay Bering Strait Canada Greenland Mackenzie River Pacific |
geographic_facet |
Arctic Arctic Ocean Baffin Bay Bering Strait Canada Greenland Mackenzie River Pacific |
genre |
Arctic Arctic Ocean Arctique* Baffin Bay Baffin Bay Baffin Bering Strait Greenland Mackenzie river North Atlantic Sea ice Subarctic |
genre_facet |
Arctic Arctic Ocean Arctique* Baffin Bay Baffin Bay Baffin Bering Strait Greenland Mackenzie river North Atlantic Sea ice Subarctic |
op_relation |
Géographie physique et Quaternaire vol. 50 no. 2 (1996) http://id.erudit.org/iderudit/033087ar doi:10.7202/033087ar |
op_rights |
Tous droits réservés © Les Presses de l'Université de Montréal, 1996 |
op_doi |
https://doi.org/10.7202/033087ar |
container_title |
Géographie physique et Quaternaire |
container_volume |
50 |
container_issue |
2 |
container_start_page |
125 |
op_container_end_page |
184 |
_version_ |
1766309856431570944 |