A Silurian U–Pb age for the Cape St. Mary's sills, Avalon Peninsula, Newfoundland, Canada: implications for Silurian orogenesis in the Avalon Zone
Mafic sills from Cape St. Mary's on the Avalon Peninsula of Newfoundland give an U–Pb baddeleyite age of 441 ± 2 Ma. This age corresponds with the earliest ages recorded for the climactic Silurian orogenic event that dominantly affected rocks of the Central Mobile Belt in Newfoundland. The age...
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crcansciencepubl:10.1139/e93-138 2024-04-07T07:54:08+00:00 A Silurian U–Pb age for the Cape St. Mary's sills, Avalon Peninsula, Newfoundland, Canada: implications for Silurian orogenesis in the Avalon Zone Greenough, John D. Kamo, Sandra L. Krogh, Thomas E. 1993 http://dx.doi.org/10.1139/e93-138 http://www.nrcresearchpress.com/doi/pdf/10.1139/e93-138 fr fre Canadian Science Publishing http://www.nrcresearchpress.com/page/about/CorporateTextAndDataMining Canadian Journal of Earth Sciences volume 30, issue 8, page 1607-1612 ISSN 0008-4077 1480-3313 General Earth and Planetary Sciences journal-article 1993 crcansciencepubl https://doi.org/10.1139/e93-138 2024-03-08T00:37:47Z Mafic sills from Cape St. Mary's on the Avalon Peninsula of Newfoundland give an U–Pb baddeleyite age of 441 ± 2 Ma. This age corresponds with the earliest ages recorded for the climactic Silurian orogenic event that dominantly affected rocks of the Central Mobile Belt in Newfoundland. The age is consistent with but in no way necessitates that the Avalon and Gander zones were juxtaposed during the Silurian. Because sills tend to form in poorly lithified and undeformed sedimentary rocks, it is unlikely that Cambrian sediments hosting the sills were affected by Ordovician orogenic events that strongly affected central Newfoundland. Negative Nb and Ti anomalies on mid-ocean-ridge basalt normalized diagrams show that the sill geochemistry is consistent with formation in a transpressional tectonic environment. Mafic magmas clearly associated with the Silurian event share these chemical and tectonic affinities. Thus both the age and geochemical data are consistent with but do not require a link between the Gander and Avalon zones during the Silurian. If the two zones were joined prior to the Silurian then the Avalon must have been distal to both the Ordovician and Silurian orogenic activity. Further, considerable post-Silurian movement would have had to occur along the bounding Hermitage–Dover fault to account for contrasts in the intensity of metamorphism, plutonism, and deformation between the Gander and Avalon zones. Article in Journal/Newspaper Newfoundland Canadian Science Publishing Canada Dover ENVELOPE(-55.753,-55.753,-83.777,-83.777) Canadian Journal of Earth Sciences 30 8 1607 1612 |
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Canadian Science Publishing |
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crcansciencepubl |
language |
French |
topic |
General Earth and Planetary Sciences |
spellingShingle |
General Earth and Planetary Sciences Greenough, John D. Kamo, Sandra L. Krogh, Thomas E. A Silurian U–Pb age for the Cape St. Mary's sills, Avalon Peninsula, Newfoundland, Canada: implications for Silurian orogenesis in the Avalon Zone |
topic_facet |
General Earth and Planetary Sciences |
description |
Mafic sills from Cape St. Mary's on the Avalon Peninsula of Newfoundland give an U–Pb baddeleyite age of 441 ± 2 Ma. This age corresponds with the earliest ages recorded for the climactic Silurian orogenic event that dominantly affected rocks of the Central Mobile Belt in Newfoundland. The age is consistent with but in no way necessitates that the Avalon and Gander zones were juxtaposed during the Silurian. Because sills tend to form in poorly lithified and undeformed sedimentary rocks, it is unlikely that Cambrian sediments hosting the sills were affected by Ordovician orogenic events that strongly affected central Newfoundland. Negative Nb and Ti anomalies on mid-ocean-ridge basalt normalized diagrams show that the sill geochemistry is consistent with formation in a transpressional tectonic environment. Mafic magmas clearly associated with the Silurian event share these chemical and tectonic affinities. Thus both the age and geochemical data are consistent with but do not require a link between the Gander and Avalon zones during the Silurian. If the two zones were joined prior to the Silurian then the Avalon must have been distal to both the Ordovician and Silurian orogenic activity. Further, considerable post-Silurian movement would have had to occur along the bounding Hermitage–Dover fault to account for contrasts in the intensity of metamorphism, plutonism, and deformation between the Gander and Avalon zones. |
format |
Article in Journal/Newspaper |
author |
Greenough, John D. Kamo, Sandra L. Krogh, Thomas E. |
author_facet |
Greenough, John D. Kamo, Sandra L. Krogh, Thomas E. |
author_sort |
Greenough, John D. |
title |
A Silurian U–Pb age for the Cape St. Mary's sills, Avalon Peninsula, Newfoundland, Canada: implications for Silurian orogenesis in the Avalon Zone |
title_short |
A Silurian U–Pb age for the Cape St. Mary's sills, Avalon Peninsula, Newfoundland, Canada: implications for Silurian orogenesis in the Avalon Zone |
title_full |
A Silurian U–Pb age for the Cape St. Mary's sills, Avalon Peninsula, Newfoundland, Canada: implications for Silurian orogenesis in the Avalon Zone |
title_fullStr |
A Silurian U–Pb age for the Cape St. Mary's sills, Avalon Peninsula, Newfoundland, Canada: implications for Silurian orogenesis in the Avalon Zone |
title_full_unstemmed |
A Silurian U–Pb age for the Cape St. Mary's sills, Avalon Peninsula, Newfoundland, Canada: implications for Silurian orogenesis in the Avalon Zone |
title_sort |
silurian u–pb age for the cape st. mary's sills, avalon peninsula, newfoundland, canada: implications for silurian orogenesis in the avalon zone |
publisher |
Canadian Science Publishing |
publishDate |
1993 |
url |
http://dx.doi.org/10.1139/e93-138 http://www.nrcresearchpress.com/doi/pdf/10.1139/e93-138 |
long_lat |
ENVELOPE(-55.753,-55.753,-83.777,-83.777) |
geographic |
Canada Dover |
geographic_facet |
Canada Dover |
genre |
Newfoundland |
genre_facet |
Newfoundland |
op_source |
Canadian Journal of Earth Sciences volume 30, issue 8, page 1607-1612 ISSN 0008-4077 1480-3313 |
op_rights |
http://www.nrcresearchpress.com/page/about/CorporateTextAndDataMining |
op_doi |
https://doi.org/10.1139/e93-138 |
container_title |
Canadian Journal of Earth Sciences |
container_volume |
30 |
container_issue |
8 |
container_start_page |
1607 |
op_container_end_page |
1612 |
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1795670470606979072 |