U – Pb zircon date from Avalonian Cape Breton Island and geochronologic calibration of the Early Ordovician
A U–Pb zircon date of 483 ± 1 Ma is recorded from an uppermost Tremadoc K-bentonite from the Chesley Drive Group on McLeod Brook, eastern Cape Breton Island. The associated fauna, with the trilobite Peltocare rotundifrons, is also known from the Reversing Falls section in Saint John, New Brunswick,...
Published in: | Canadian Journal of Earth Sciences |
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Language: | English |
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Canadian Science Publishing
1997
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Online Access: | http://dx.doi.org/10.1139/e17-059 http://www.nrcresearchpress.com/doi/pdf/10.1139/e17-059 |
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crcansciencepubl:10.1139/e17-059 2024-10-13T14:06:27+00:00 U – Pb zircon date from Avalonian Cape Breton Island and geochronologic calibration of the Early Ordovician Landing, Ed Bowring, Samuel A. Davidek, Kathleen L. Fortey, Richard A. 1997 http://dx.doi.org/10.1139/e17-059 http://www.nrcresearchpress.com/doi/pdf/10.1139/e17-059 en eng Canadian Science Publishing http://www.nrcresearchpress.com/page/about/CorporateTextAndDataMining Canadian Journal of Earth Sciences volume 34, issue 5, page 724-730 ISSN 0008-4077 1480-3313 journal-article 1997 crcansciencepubl https://doi.org/10.1139/e17-059 2024-09-19T04:09:47Z A U–Pb zircon date of 483 ± 1 Ma is recorded from an uppermost Tremadoc K-bentonite from the Chesley Drive Group on McLeod Brook, eastern Cape Breton Island. The associated fauna, with the trilobite Peltocare rotundifrons, is also known from the Reversing Falls section in Saint John, New Brunswick, and the traditional reference of the latter section to the Arenig is incorrect. A 483 ± 1 Ma age is significantly older than a U – Pb zircon age reported from the classical base of the Arenig Series in north Wales and about 10 Ma older than strata regarded herein as upper Arenig in central Newfoundland. If the global standard for the base of the Arenig is defined at the Tetragraptus approximatus Zone base, then the base of the type Arenig in Wales is younger than the latter horizon. The McLeod Brook occurrence is from an uppermost Tremadoc (Hunnebergian Stage) interval that has been removed below the unconformity in north Wales. The age of the Tremadoc –Arenig series boundary remains uncertain; however, a tentative estimate that it is significantly younger than 483 Ma is suggested by fossil evidence. Article in Journal/Newspaper Breton Island Newfoundland Canadian Science Publishing Breton Island ENVELOPE(141.383,141.383,-66.800,-66.800) McLeod ENVELOPE(-127.689,-127.689,55.254,55.254) Canadian Journal of Earth Sciences 34 5 724 730 |
institution |
Open Polar |
collection |
Canadian Science Publishing |
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crcansciencepubl |
language |
English |
description |
A U–Pb zircon date of 483 ± 1 Ma is recorded from an uppermost Tremadoc K-bentonite from the Chesley Drive Group on McLeod Brook, eastern Cape Breton Island. The associated fauna, with the trilobite Peltocare rotundifrons, is also known from the Reversing Falls section in Saint John, New Brunswick, and the traditional reference of the latter section to the Arenig is incorrect. A 483 ± 1 Ma age is significantly older than a U – Pb zircon age reported from the classical base of the Arenig Series in north Wales and about 10 Ma older than strata regarded herein as upper Arenig in central Newfoundland. If the global standard for the base of the Arenig is defined at the Tetragraptus approximatus Zone base, then the base of the type Arenig in Wales is younger than the latter horizon. The McLeod Brook occurrence is from an uppermost Tremadoc (Hunnebergian Stage) interval that has been removed below the unconformity in north Wales. The age of the Tremadoc –Arenig series boundary remains uncertain; however, a tentative estimate that it is significantly younger than 483 Ma is suggested by fossil evidence. |
format |
Article in Journal/Newspaper |
author |
Landing, Ed Bowring, Samuel A. Davidek, Kathleen L. Fortey, Richard A. |
spellingShingle |
Landing, Ed Bowring, Samuel A. Davidek, Kathleen L. Fortey, Richard A. U – Pb zircon date from Avalonian Cape Breton Island and geochronologic calibration of the Early Ordovician |
author_facet |
Landing, Ed Bowring, Samuel A. Davidek, Kathleen L. Fortey, Richard A. |
author_sort |
Landing, Ed |
title |
U – Pb zircon date from Avalonian Cape Breton Island and geochronologic calibration of the Early Ordovician |
title_short |
U – Pb zircon date from Avalonian Cape Breton Island and geochronologic calibration of the Early Ordovician |
title_full |
U – Pb zircon date from Avalonian Cape Breton Island and geochronologic calibration of the Early Ordovician |
title_fullStr |
U – Pb zircon date from Avalonian Cape Breton Island and geochronologic calibration of the Early Ordovician |
title_full_unstemmed |
U – Pb zircon date from Avalonian Cape Breton Island and geochronologic calibration of the Early Ordovician |
title_sort |
u – pb zircon date from avalonian cape breton island and geochronologic calibration of the early ordovician |
publisher |
Canadian Science Publishing |
publishDate |
1997 |
url |
http://dx.doi.org/10.1139/e17-059 http://www.nrcresearchpress.com/doi/pdf/10.1139/e17-059 |
long_lat |
ENVELOPE(141.383,141.383,-66.800,-66.800) ENVELOPE(-127.689,-127.689,55.254,55.254) |
geographic |
Breton Island McLeod |
geographic_facet |
Breton Island McLeod |
genre |
Breton Island Newfoundland |
genre_facet |
Breton Island Newfoundland |
op_source |
Canadian Journal of Earth Sciences volume 34, issue 5, page 724-730 ISSN 0008-4077 1480-3313 |
op_rights |
http://www.nrcresearchpress.com/page/about/CorporateTextAndDataMining |
op_doi |
https://doi.org/10.1139/e17-059 |
container_title |
Canadian Journal of Earth Sciences |
container_volume |
34 |
container_issue |
5 |
container_start_page |
724 |
op_container_end_page |
730 |
_version_ |
1812812607947538432 |