Early Paleozoic chronology: a review in light of new U – Pb zircon ages from Newfoundland and Britain
The time scale for the Cambrian through Early Devonian periods is revised using new U–Pb ages from volcanic and pyroclastic rocks in sequences that are stratigraphically well defined. A rhyolite flow from the latest Precambrian, dated at 551.4 ± 5.8 Ma, gives a maximum age for the base of the Cambri...
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Canadian Science Publishing
1995
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crcansciencepubl:10.1139/e95-032 2024-10-13T14:09:06+00:00 Early Paleozoic chronology: a review in light of new U – Pb zircon ages from Newfoundland and Britain Tucker, R. D. McKerrow, W.S. 1995 http://dx.doi.org/10.1139/e95-032 http://www.nrcresearchpress.com/doi/pdf/10.1139/e95-032 en eng Canadian Science Publishing http://www.nrcresearchpress.com/page/about/CorporateTextAndDataMining Canadian Journal of Earth Sciences volume 32, issue 4, page 368-379 ISSN 0008-4077 1480-3313 journal-article 1995 crcansciencepubl https://doi.org/10.1139/e95-032 2024-09-19T04:09:48Z The time scale for the Cambrian through Early Devonian periods is revised using new U–Pb ages from volcanic and pyroclastic rocks in sequences that are stratigraphically well defined. A rhyolite flow from the latest Precambrian, dated at 551.4 ± 5.8 Ma, gives a maximum age for the base of the Cambrian (Phycodes pedum Zone) at Fortune Bay, Newfoundland. The age ranges of several Ordovician and Silurian series are now established to within 2–3 Ma based on stratigraphically controlled samples from Britain. A basal Llandeilo ash has an age of 460.4 ± 2.2 Ma; a basal Caradoc lava has an age of 456.1 ± 1.8 ± Ma; and K-bentonites from the latest Llandovery and latest Ludlow have ages of 430.1 ± 2.4 and 420.2 ± 3.9 Ma, respectively. Using other data from the literature, we interpolate the base of the Cambrian to be near 545 Ma, the base of the Ordovician as ca. 495 Ma, and the base of the Silurian as ca. 443 Ma. While we have a good estimate for the base of the Middle Devonian (at ca. 391 Ma), the base of the Devonian is less precise, probably around 417 Ma. Article in Journal/Newspaper Newfoundland Canadian Science Publishing Canadian Journal of Earth Sciences 32 4 368 379 |
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Open Polar |
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Canadian Science Publishing |
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crcansciencepubl |
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English |
description |
The time scale for the Cambrian through Early Devonian periods is revised using new U–Pb ages from volcanic and pyroclastic rocks in sequences that are stratigraphically well defined. A rhyolite flow from the latest Precambrian, dated at 551.4 ± 5.8 Ma, gives a maximum age for the base of the Cambrian (Phycodes pedum Zone) at Fortune Bay, Newfoundland. The age ranges of several Ordovician and Silurian series are now established to within 2–3 Ma based on stratigraphically controlled samples from Britain. A basal Llandeilo ash has an age of 460.4 ± 2.2 Ma; a basal Caradoc lava has an age of 456.1 ± 1.8 ± Ma; and K-bentonites from the latest Llandovery and latest Ludlow have ages of 430.1 ± 2.4 and 420.2 ± 3.9 Ma, respectively. Using other data from the literature, we interpolate the base of the Cambrian to be near 545 Ma, the base of the Ordovician as ca. 495 Ma, and the base of the Silurian as ca. 443 Ma. While we have a good estimate for the base of the Middle Devonian (at ca. 391 Ma), the base of the Devonian is less precise, probably around 417 Ma. |
format |
Article in Journal/Newspaper |
author |
Tucker, R. D. McKerrow, W.S. |
spellingShingle |
Tucker, R. D. McKerrow, W.S. Early Paleozoic chronology: a review in light of new U – Pb zircon ages from Newfoundland and Britain |
author_facet |
Tucker, R. D. McKerrow, W.S. |
author_sort |
Tucker, R. D. |
title |
Early Paleozoic chronology: a review in light of new U – Pb zircon ages from Newfoundland and Britain |
title_short |
Early Paleozoic chronology: a review in light of new U – Pb zircon ages from Newfoundland and Britain |
title_full |
Early Paleozoic chronology: a review in light of new U – Pb zircon ages from Newfoundland and Britain |
title_fullStr |
Early Paleozoic chronology: a review in light of new U – Pb zircon ages from Newfoundland and Britain |
title_full_unstemmed |
Early Paleozoic chronology: a review in light of new U – Pb zircon ages from Newfoundland and Britain |
title_sort |
early paleozoic chronology: a review in light of new u – pb zircon ages from newfoundland and britain |
publisher |
Canadian Science Publishing |
publishDate |
1995 |
url |
http://dx.doi.org/10.1139/e95-032 http://www.nrcresearchpress.com/doi/pdf/10.1139/e95-032 |
genre |
Newfoundland |
genre_facet |
Newfoundland |
op_source |
Canadian Journal of Earth Sciences volume 32, issue 4, page 368-379 ISSN 0008-4077 1480-3313 |
op_rights |
http://www.nrcresearchpress.com/page/about/CorporateTextAndDataMining |
op_doi |
https://doi.org/10.1139/e95-032 |
container_title |
Canadian Journal of Earth Sciences |
container_volume |
32 |
container_issue |
4 |
container_start_page |
368 |
op_container_end_page |
379 |
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1812815960703238144 |