Lower Ordovician (Arenig–Llanvirn) graptolites from the Notre Dame Subzone, central Newfoundland
Many lower Paleozoic rocks in the Notre Dame Subzone of central Newfoundland are of unknown or imprecise age. Several new Lower Ordovician graptolite occurrences are here reported and earlier records revised. New graptolite localities in the Balsam Bud Cove Formation at Snooks Arm on the Baie Verte...
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Canadian Science Publishing
1992
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Online Access: | http://dx.doi.org/10.1139/e92-135 http://www.nrcresearchpress.com/doi/pdf/10.1139/e92-135 |
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crcansciencepubl:10.1139/e92-135 2024-09-15T17:57:09+00:00 Lower Ordovician (Arenig–Llanvirn) graptolites from the Notre Dame Subzone, central Newfoundland Williams, S. Henry 1992 http://dx.doi.org/10.1139/e92-135 http://www.nrcresearchpress.com/doi/pdf/10.1139/e92-135 en eng Canadian Science Publishing http://www.nrcresearchpress.com/page/about/CorporateTextAndDataMining Canadian Journal of Earth Sciences volume 29, issue 8, page 1717-1733 ISSN 0008-4077 1480-3313 journal-article 1992 crcansciencepubl https://doi.org/10.1139/e92-135 2024-08-01T04:10:03Z Many lower Paleozoic rocks in the Notre Dame Subzone of central Newfoundland are of unknown or imprecise age. Several new Lower Ordovician graptolite occurrences are here reported and earlier records revised. New graptolite localities in the Balsam Bud Cove Formation at Snooks Arm on the Baie Verte Peninsula, previously recorded as "early Ordovician (Arenig)" have yielded an assemblage identical to that found in the middle part of Bed 11 of the Cow Head Group, western Newfoundland, indicating a probable lower Didymograptus bifidus Zone age. At Corner Pond, southeast of Corner Brook, an abundant, diverse fauna from the Corner Pond formation indicates a marginally older age for the black shales than those at Snooks Arm (Pendeograptus fruticosus Zone, equivalent to lower Bed 11). Black shales associated with felsic volcanics and limestone breccia belonging to the Cutwell Group at Lushes Bight, on Long Island, western Notre Dame Bay, which were previously assigned to the widespread black shales of the Lawrence Harbour Formation and equivalents in the Exploits Subzone, contain a rich lower Llanvirn (Paraglossograptus tentaculatus Zone) graptolite assemblage. This agrees with ages established using other macrofossils and conodonts from the associated limestones. In contrast, a lower shale unit from older strata at Southern Head on the eastern end of the island yields a late Arenig Isograptus victoriae maximus Zone assemblage. These newly discovered graptolite faunas provide precise ages for the upper and lower parts of the volcano-sedimentary sequence on Long Island. Interestingly, all four graptolite assemblages discussed here are of open-ocean affinity, permitting accurate correlation with localities not only in western Newfoundland but also elsewhere in the world. Article in Journal/Newspaper Baie Verte Newfoundland Canadian Science Publishing Canadian Journal of Earth Sciences 29 8 1717 1733 |
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Open Polar |
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Canadian Science Publishing |
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crcansciencepubl |
language |
English |
description |
Many lower Paleozoic rocks in the Notre Dame Subzone of central Newfoundland are of unknown or imprecise age. Several new Lower Ordovician graptolite occurrences are here reported and earlier records revised. New graptolite localities in the Balsam Bud Cove Formation at Snooks Arm on the Baie Verte Peninsula, previously recorded as "early Ordovician (Arenig)" have yielded an assemblage identical to that found in the middle part of Bed 11 of the Cow Head Group, western Newfoundland, indicating a probable lower Didymograptus bifidus Zone age. At Corner Pond, southeast of Corner Brook, an abundant, diverse fauna from the Corner Pond formation indicates a marginally older age for the black shales than those at Snooks Arm (Pendeograptus fruticosus Zone, equivalent to lower Bed 11). Black shales associated with felsic volcanics and limestone breccia belonging to the Cutwell Group at Lushes Bight, on Long Island, western Notre Dame Bay, which were previously assigned to the widespread black shales of the Lawrence Harbour Formation and equivalents in the Exploits Subzone, contain a rich lower Llanvirn (Paraglossograptus tentaculatus Zone) graptolite assemblage. This agrees with ages established using other macrofossils and conodonts from the associated limestones. In contrast, a lower shale unit from older strata at Southern Head on the eastern end of the island yields a late Arenig Isograptus victoriae maximus Zone assemblage. These newly discovered graptolite faunas provide precise ages for the upper and lower parts of the volcano-sedimentary sequence on Long Island. Interestingly, all four graptolite assemblages discussed here are of open-ocean affinity, permitting accurate correlation with localities not only in western Newfoundland but also elsewhere in the world. |
format |
Article in Journal/Newspaper |
author |
Williams, S. Henry |
spellingShingle |
Williams, S. Henry Lower Ordovician (Arenig–Llanvirn) graptolites from the Notre Dame Subzone, central Newfoundland |
author_facet |
Williams, S. Henry |
author_sort |
Williams, S. Henry |
title |
Lower Ordovician (Arenig–Llanvirn) graptolites from the Notre Dame Subzone, central Newfoundland |
title_short |
Lower Ordovician (Arenig–Llanvirn) graptolites from the Notre Dame Subzone, central Newfoundland |
title_full |
Lower Ordovician (Arenig–Llanvirn) graptolites from the Notre Dame Subzone, central Newfoundland |
title_fullStr |
Lower Ordovician (Arenig–Llanvirn) graptolites from the Notre Dame Subzone, central Newfoundland |
title_full_unstemmed |
Lower Ordovician (Arenig–Llanvirn) graptolites from the Notre Dame Subzone, central Newfoundland |
title_sort |
lower ordovician (arenig–llanvirn) graptolites from the notre dame subzone, central newfoundland |
publisher |
Canadian Science Publishing |
publishDate |
1992 |
url |
http://dx.doi.org/10.1139/e92-135 http://www.nrcresearchpress.com/doi/pdf/10.1139/e92-135 |
genre |
Baie Verte Newfoundland |
genre_facet |
Baie Verte Newfoundland |
op_source |
Canadian Journal of Earth Sciences volume 29, issue 8, page 1717-1733 ISSN 0008-4077 1480-3313 |
op_rights |
http://www.nrcresearchpress.com/page/about/CorporateTextAndDataMining |
op_doi |
https://doi.org/10.1139/e92-135 |
container_title |
Canadian Journal of Earth Sciences |
container_volume |
29 |
container_issue |
8 |
container_start_page |
1717 |
op_container_end_page |
1733 |
_version_ |
1810433325306740736 |