High-resolution isotope stratigraphy of the Lower Ordovician St. George Group of western Newfoundland, Canada: implications for global correlation
The Lower Ordovician St. George Group of western Newfoundland consists mainly of shallow-marine-platform carbonates (∼500 m thick). It is formed, from bottom to top, of the Watts Bight, Boat Harbour, Catoche, and Aguathuna formations. The top boundary of the group is marked by the regional St. Georg...
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crcansciencepubl:10.1139/e09-032 2024-04-28T08:28:46+00:00 High-resolution isotope stratigraphy of the Lower Ordovician St. George Group of western Newfoundland, Canada: implications for global correlation Azmy, Karem Lavoie, Denis Dix, George 2009 http://dx.doi.org/10.1139/e09-032 http://www.nrcresearchpress.com/doi/full-xml/10.1139/E09-032 http://www.nrcresearchpress.com/doi/pdf/10.1139/E09-032 en eng Canadian Science Publishing http://www.nrcresearchpress.com/page/about/CorporateTextAndDataMining Canadian Journal of Earth Sciences volume 46, issue 6, page 403-423 ISSN 0008-4077 1480-3313 General Earth and Planetary Sciences journal-article 2009 crcansciencepubl https://doi.org/10.1139/e09-032 2024-04-09T06:56:29Z The Lower Ordovician St. George Group of western Newfoundland consists mainly of shallow-marine-platform carbonates (∼500 m thick). It is formed, from bottom to top, of the Watts Bight, Boat Harbour, Catoche, and Aguathuna formations. The top boundary of the group is marked by the regional St. George Unconformity. Outcrops and a few cores from western Newfoundland were sampled at high resolution and the extracted micritic materials were investigated for their petrographic and geochemical criteria to evaluate their degree of preservation. The δ 13 C and δ 18 O values of well-preserved micrite microsamples range from –4.2‰ to 0‰ (VPDB) and from –11.3‰ to –2.9‰ (VPDB), respectively. The δ 13 C carb profile of the St. George Group carbonates reveals several negative shifts, which vary between ∼2‰ and 3‰ and are generally associated with unconformities–disconformities or thin shale interbeds, thus reflecting the effect of or link with significant sea-level changes. The St. George Unconformity is associated with a negative δ 13 C carb shift (∼2‰) on the profile and correlated with major lowstand (around the end of Arenig) on the local sea-level reconstruction and also on those from the Baltic region and central Australia, thus suggesting that the St. George Group Unconformity might have likely had an eustatic component that contributed to the development–enhancement of the paleomargin. Other similar δ 13 C carb shifts have been recorded on the St. George profile, but it is hard to evaluate their global extension due to the low resolution of the documented global Lower Ordovician (Tremadoc – middle Arenig) δ 13 C carb profile. Article in Journal/Newspaper Newfoundland Canadian Science Publishing Canadian Journal of Earth Sciences 46 6 403 423 |
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General Earth and Planetary Sciences |
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General Earth and Planetary Sciences Azmy, Karem Lavoie, Denis High-resolution isotope stratigraphy of the Lower Ordovician St. George Group of western Newfoundland, Canada: implications for global correlation |
topic_facet |
General Earth and Planetary Sciences |
description |
The Lower Ordovician St. George Group of western Newfoundland consists mainly of shallow-marine-platform carbonates (∼500 m thick). It is formed, from bottom to top, of the Watts Bight, Boat Harbour, Catoche, and Aguathuna formations. The top boundary of the group is marked by the regional St. George Unconformity. Outcrops and a few cores from western Newfoundland were sampled at high resolution and the extracted micritic materials were investigated for their petrographic and geochemical criteria to evaluate their degree of preservation. The δ 13 C and δ 18 O values of well-preserved micrite microsamples range from –4.2‰ to 0‰ (VPDB) and from –11.3‰ to –2.9‰ (VPDB), respectively. The δ 13 C carb profile of the St. George Group carbonates reveals several negative shifts, which vary between ∼2‰ and 3‰ and are generally associated with unconformities–disconformities or thin shale interbeds, thus reflecting the effect of or link with significant sea-level changes. The St. George Unconformity is associated with a negative δ 13 C carb shift (∼2‰) on the profile and correlated with major lowstand (around the end of Arenig) on the local sea-level reconstruction and also on those from the Baltic region and central Australia, thus suggesting that the St. George Group Unconformity might have likely had an eustatic component that contributed to the development–enhancement of the paleomargin. Other similar δ 13 C carb shifts have been recorded on the St. George profile, but it is hard to evaluate their global extension due to the low resolution of the documented global Lower Ordovician (Tremadoc – middle Arenig) δ 13 C carb profile. |
author2 |
Dix, George |
format |
Article in Journal/Newspaper |
author |
Azmy, Karem Lavoie, Denis |
author_facet |
Azmy, Karem Lavoie, Denis |
author_sort |
Azmy, Karem |
title |
High-resolution isotope stratigraphy of the Lower Ordovician St. George Group of western Newfoundland, Canada: implications for global correlation |
title_short |
High-resolution isotope stratigraphy of the Lower Ordovician St. George Group of western Newfoundland, Canada: implications for global correlation |
title_full |
High-resolution isotope stratigraphy of the Lower Ordovician St. George Group of western Newfoundland, Canada: implications for global correlation |
title_fullStr |
High-resolution isotope stratigraphy of the Lower Ordovician St. George Group of western Newfoundland, Canada: implications for global correlation |
title_full_unstemmed |
High-resolution isotope stratigraphy of the Lower Ordovician St. George Group of western Newfoundland, Canada: implications for global correlation |
title_sort |
high-resolution isotope stratigraphy of the lower ordovician st. george group of western newfoundland, canada: implications for global correlation |
publisher |
Canadian Science Publishing |
publishDate |
2009 |
url |
http://dx.doi.org/10.1139/e09-032 http://www.nrcresearchpress.com/doi/full-xml/10.1139/E09-032 http://www.nrcresearchpress.com/doi/pdf/10.1139/E09-032 |
genre |
Newfoundland |
genre_facet |
Newfoundland |
op_source |
Canadian Journal of Earth Sciences volume 46, issue 6, page 403-423 ISSN 0008-4077 1480-3313 |
op_rights |
http://www.nrcresearchpress.com/page/about/CorporateTextAndDataMining |
op_doi |
https://doi.org/10.1139/e09-032 |
container_title |
Canadian Journal of Earth Sciences |
container_volume |
46 |
container_issue |
6 |
container_start_page |
403 |
op_container_end_page |
423 |
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1797587191808917504 |