Timing and consequences of Bering Strait opening: new insights from 40Ar/39 1 Ar dating 2 of the Barmur Group (Tjörnes beds), northern Iceland
The Barmur Group (informally Tjörnes beds) sedimentary succession of northern Iceland is key to reconstructing the opening of the Bering Strait oceanic gateway because these rocks record migration of bivalve molluscs from the Pacific to the Atlantic via the Arctic. However, the timing of the migrati...
Published in: | Paleoceanography and Paleoclimatology |
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Language: | English |
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American Geophysical Union
2023
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Online Access: | https://eprints.gla.ac.uk/295234/ https://eprints.gla.ac.uk/295234/1/295234.pdf |
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ftuglasgow:oai:eprints.gla.ac.uk:295234 2023-06-11T04:09:01+02:00 Timing and consequences of Bering Strait opening: new insights from 40Ar/39 1 Ar dating 2 of the Barmur Group (Tjörnes beds), northern Iceland Hall, Jonathan R. Allison, Matthew S. Papadopoulos, Max T. Barfod, Dan N. Jones, Stephen M. 2023-04 text https://eprints.gla.ac.uk/295234/ https://eprints.gla.ac.uk/295234/1/295234.pdf en eng American Geophysical Union https://eprints.gla.ac.uk/295234/1/295234.pdf Hall, J. R., Allison, M. S., Papadopoulos, M. T., Barfod, D. N. <http://eprints.gla.ac.uk/view/author/4012.html> and Jones, S. M. (2023) Timing and consequences of Bering Strait opening: new insights from 40Ar/39 1 Ar dating 2 of the Barmur Group (Tjörnes beds), northern Iceland. Paleoceanography and Paleoclimatology <https://eprints.gla.ac.uk/view/journal_volume/Paleoceanography_and_Paleoclimatology.html>, 38, e2022PA004. (doi:10.1029/2022PA004539 <https://doi.org/10.1029/2022PA004539>) cc_by_4 Articles PeerReviewed 2023 ftuglasgow https://doi.org/10.1029/2022PA004539 2023-04-27T22:09:26Z The Barmur Group (informally Tjörnes beds) sedimentary succession of northern Iceland is key to reconstructing the opening of the Bering Strait oceanic gateway because these rocks record migration of bivalve molluscs from the Pacific to the Atlantic via the Arctic. However, the timing of the migration event is poorly constrained owing to a lack of reliable absolute ages. To address this problem, we present the first Ar-Ar radiometric dates from four basaltic lavas that underlie, are intercalated with, and overlie the Barmur Group, and integrate them with existing paleomagnetic records. We show that the Barmur Group has a latest Miocene to early Pliocene age range (c. 6.0–4.4 Ma; C3r–C3n.2n), older than all previous age models. Thus, the Barmur Group does not record the mid-Piacenzian Warm Period, contra some previous suggestions. Abundant Pacific bivalve molluscs appeared in the Barmur Group during subchrons C3n.4n–C3n.3r at 5.235–4.896 Ma, over 1.3 million years earlier than previously suggested. Appearance of Pacific bivalves in the northern Atlantic occurred shortly after the 5.6–5.4 Ma age previously inferred for first appearance of Arctic bivalves in the Pacific. Thus, our data suggest that first opening of the Bering Strait gateway by the latest Miocene (c. 5.5 Ma) was soon followed by bidirectional trans-Arctic faunal exchange, and argue against a hypothesized two-stage faunal exchange process spanning c. 2 million years. Our results also confirm that first opening of the Bering Strait gateway was not directly associated with the growth of large northern hemisphere icesheets, which occurred several million years later. Article in Journal/Newspaper Arctic Bering Strait Iceland University of Glasgow: Enlighten - Publications Arctic Bering Strait Pacific Tjörnes ENVELOPE(-17.087,-17.087,66.152,66.152) Barmur ENVELOPE(-7.013,-7.013,62.097,62.097) Paleoceanography and Paleoclimatology 38 4 |
institution |
Open Polar |
collection |
University of Glasgow: Enlighten - Publications |
op_collection_id |
ftuglasgow |
language |
English |
description |
The Barmur Group (informally Tjörnes beds) sedimentary succession of northern Iceland is key to reconstructing the opening of the Bering Strait oceanic gateway because these rocks record migration of bivalve molluscs from the Pacific to the Atlantic via the Arctic. However, the timing of the migration event is poorly constrained owing to a lack of reliable absolute ages. To address this problem, we present the first Ar-Ar radiometric dates from four basaltic lavas that underlie, are intercalated with, and overlie the Barmur Group, and integrate them with existing paleomagnetic records. We show that the Barmur Group has a latest Miocene to early Pliocene age range (c. 6.0–4.4 Ma; C3r–C3n.2n), older than all previous age models. Thus, the Barmur Group does not record the mid-Piacenzian Warm Period, contra some previous suggestions. Abundant Pacific bivalve molluscs appeared in the Barmur Group during subchrons C3n.4n–C3n.3r at 5.235–4.896 Ma, over 1.3 million years earlier than previously suggested. Appearance of Pacific bivalves in the northern Atlantic occurred shortly after the 5.6–5.4 Ma age previously inferred for first appearance of Arctic bivalves in the Pacific. Thus, our data suggest that first opening of the Bering Strait gateway by the latest Miocene (c. 5.5 Ma) was soon followed by bidirectional trans-Arctic faunal exchange, and argue against a hypothesized two-stage faunal exchange process spanning c. 2 million years. Our results also confirm that first opening of the Bering Strait gateway was not directly associated with the growth of large northern hemisphere icesheets, which occurred several million years later. |
format |
Article in Journal/Newspaper |
author |
Hall, Jonathan R. Allison, Matthew S. Papadopoulos, Max T. Barfod, Dan N. Jones, Stephen M. |
spellingShingle |
Hall, Jonathan R. Allison, Matthew S. Papadopoulos, Max T. Barfod, Dan N. Jones, Stephen M. Timing and consequences of Bering Strait opening: new insights from 40Ar/39 1 Ar dating 2 of the Barmur Group (Tjörnes beds), northern Iceland |
author_facet |
Hall, Jonathan R. Allison, Matthew S. Papadopoulos, Max T. Barfod, Dan N. Jones, Stephen M. |
author_sort |
Hall, Jonathan R. |
title |
Timing and consequences of Bering Strait opening: new insights from 40Ar/39 1 Ar dating 2 of the Barmur Group (Tjörnes beds), northern Iceland |
title_short |
Timing and consequences of Bering Strait opening: new insights from 40Ar/39 1 Ar dating 2 of the Barmur Group (Tjörnes beds), northern Iceland |
title_full |
Timing and consequences of Bering Strait opening: new insights from 40Ar/39 1 Ar dating 2 of the Barmur Group (Tjörnes beds), northern Iceland |
title_fullStr |
Timing and consequences of Bering Strait opening: new insights from 40Ar/39 1 Ar dating 2 of the Barmur Group (Tjörnes beds), northern Iceland |
title_full_unstemmed |
Timing and consequences of Bering Strait opening: new insights from 40Ar/39 1 Ar dating 2 of the Barmur Group (Tjörnes beds), northern Iceland |
title_sort |
timing and consequences of bering strait opening: new insights from 40ar/39 1 ar dating 2 of the barmur group (tjörnes beds), northern iceland |
publisher |
American Geophysical Union |
publishDate |
2023 |
url |
https://eprints.gla.ac.uk/295234/ https://eprints.gla.ac.uk/295234/1/295234.pdf |
long_lat |
ENVELOPE(-17.087,-17.087,66.152,66.152) ENVELOPE(-7.013,-7.013,62.097,62.097) |
geographic |
Arctic Bering Strait Pacific Tjörnes Barmur |
geographic_facet |
Arctic Bering Strait Pacific Tjörnes Barmur |
genre |
Arctic Bering Strait Iceland |
genre_facet |
Arctic Bering Strait Iceland |
op_relation |
https://eprints.gla.ac.uk/295234/1/295234.pdf Hall, J. R., Allison, M. S., Papadopoulos, M. T., Barfod, D. N. <http://eprints.gla.ac.uk/view/author/4012.html> and Jones, S. M. (2023) Timing and consequences of Bering Strait opening: new insights from 40Ar/39 1 Ar dating 2 of the Barmur Group (Tjörnes beds), northern Iceland. Paleoceanography and Paleoclimatology <https://eprints.gla.ac.uk/view/journal_volume/Paleoceanography_and_Paleoclimatology.html>, 38, e2022PA004. (doi:10.1029/2022PA004539 <https://doi.org/10.1029/2022PA004539>) |
op_rights |
cc_by_4 |
op_doi |
https://doi.org/10.1029/2022PA004539 |
container_title |
Paleoceanography and Paleoclimatology |
container_volume |
38 |
container_issue |
4 |
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1768382715139194880 |