Granitoid plutons in peri-Gondwanaan terranes of Cape Breton Island, Nova Scotia, Canada: new U-Pb (zircon) age constraints
Granitoid plutons are a major component of pre-Carboniferous rocks in Cape Breton Island and knowledge of the time and tectonic setting of their emplacement is crucial for understanding the geological history of the island, guiding exploration for granite-related economic mineralization, and making...
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fterudit:oai:erudit.org:1055413ar 2023-05-15T15:46:41+02:00 Granitoid plutons in peri-Gondwanaan terranes of Cape Breton Island, Nova Scotia, Canada: new U-Pb (zircon) age constraints Barr, Sandra M. van Rooyen, Deanne White, Chris E. 2018 http://id.erudit.org/iderudit/1055413ar https://doi.org/10.4138/atlgeol.2018.002 en eng Atlantic Geoscience Society Érudit Atlantic Geology : Journal of the Atlantic Geoscience Society vol. 54 (2018) http://id.erudit.org/iderudit/1055413ar doi:10.4138/atlgeol.2018.002 All Rights Reserved ©, 2018Atlantic Geology U-Pb dating zircon granitoid plutons text 2018 fterudit https://doi.org/10.4138/atlgeol.2018.002 2020-05-30T23:10:36Z Granitoid plutons are a major component of pre-Carboniferous rocks in Cape Breton Island and knowledge of the time and tectonic setting of their emplacement is crucial for understanding the geological history of the island, guiding exploration for granite-related economic mineralization, and making along-orogen correlations. The distribution of these plutons and their petrological characteristics have been used in the past for recognizing both Laurentian and peri-Gondwanan components in Cape Breton Island, and for subdividing the peri-Gondwanan components into Ganderian and Avalonian terranes. However, ages of many plutons were assumed on the basis of field relations and petrological features compared to those of the relatively few reliably dated plutons. Seventeen new U–Pb (zircon) ages from igneous units reported here provide enhanced understanding of the distribution of pluton ages. Arc-related plutons in the Aspy terrane with ages of ca. 490 to 475 Ma likely record the Penobscottian tectonomagmatic event recognized in the Exploits subzone of central Newfoundland and New Brunswick but not previously recognized in Cape Breton Island. Arc-related Devonian plutonic activity in the same terrane is more widespread, continuous, and protracted (445 Ma to 395 Ma) than previously known. Late Devonian magmatism in the Ganderian Aspy terrane is similar in age to that in the Avalonian Mira terrane (380 to 360 Ma) but the tectonic settings are different. In contrast, magmatic activity in the Bras d’Or terrane is almost exclusively arc-related in the Late Ediacaran (580 to 540 Ma) and rift-related in the Late Cambrian (520 to 490 Ma). The new data support the terrane distinctions previously documented. Text Breton Island Newfoundland Érudit.org (Université Montréal) Breton Island ENVELOPE(141.383,141.383,-66.800,-66.800) Canada Mira ENVELOPE(10.500,10.500,-70.417,-70.417) Atlantic Geology 021 080 |
institution |
Open Polar |
collection |
Érudit.org (Université Montréal) |
op_collection_id |
fterudit |
language |
English |
topic |
U-Pb dating zircon granitoid plutons |
spellingShingle |
U-Pb dating zircon granitoid plutons Barr, Sandra M. van Rooyen, Deanne White, Chris E. Granitoid plutons in peri-Gondwanaan terranes of Cape Breton Island, Nova Scotia, Canada: new U-Pb (zircon) age constraints |
topic_facet |
U-Pb dating zircon granitoid plutons |
description |
Granitoid plutons are a major component of pre-Carboniferous rocks in Cape Breton Island and knowledge of the time and tectonic setting of their emplacement is crucial for understanding the geological history of the island, guiding exploration for granite-related economic mineralization, and making along-orogen correlations. The distribution of these plutons and their petrological characteristics have been used in the past for recognizing both Laurentian and peri-Gondwanan components in Cape Breton Island, and for subdividing the peri-Gondwanan components into Ganderian and Avalonian terranes. However, ages of many plutons were assumed on the basis of field relations and petrological features compared to those of the relatively few reliably dated plutons. Seventeen new U–Pb (zircon) ages from igneous units reported here provide enhanced understanding of the distribution of pluton ages. Arc-related plutons in the Aspy terrane with ages of ca. 490 to 475 Ma likely record the Penobscottian tectonomagmatic event recognized in the Exploits subzone of central Newfoundland and New Brunswick but not previously recognized in Cape Breton Island. Arc-related Devonian plutonic activity in the same terrane is more widespread, continuous, and protracted (445 Ma to 395 Ma) than previously known. Late Devonian magmatism in the Ganderian Aspy terrane is similar in age to that in the Avalonian Mira terrane (380 to 360 Ma) but the tectonic settings are different. In contrast, magmatic activity in the Bras d’Or terrane is almost exclusively arc-related in the Late Ediacaran (580 to 540 Ma) and rift-related in the Late Cambrian (520 to 490 Ma). The new data support the terrane distinctions previously documented. |
format |
Text |
author |
Barr, Sandra M. van Rooyen, Deanne White, Chris E. |
author_facet |
Barr, Sandra M. van Rooyen, Deanne White, Chris E. |
author_sort |
Barr, Sandra M. |
title |
Granitoid plutons in peri-Gondwanaan terranes of Cape Breton Island, Nova Scotia, Canada: new U-Pb (zircon) age constraints |
title_short |
Granitoid plutons in peri-Gondwanaan terranes of Cape Breton Island, Nova Scotia, Canada: new U-Pb (zircon) age constraints |
title_full |
Granitoid plutons in peri-Gondwanaan terranes of Cape Breton Island, Nova Scotia, Canada: new U-Pb (zircon) age constraints |
title_fullStr |
Granitoid plutons in peri-Gondwanaan terranes of Cape Breton Island, Nova Scotia, Canada: new U-Pb (zircon) age constraints |
title_full_unstemmed |
Granitoid plutons in peri-Gondwanaan terranes of Cape Breton Island, Nova Scotia, Canada: new U-Pb (zircon) age constraints |
title_sort |
granitoid plutons in peri-gondwanaan terranes of cape breton island, nova scotia, canada: new u-pb (zircon) age constraints |
publisher |
Atlantic Geoscience Society |
publishDate |
2018 |
url |
http://id.erudit.org/iderudit/1055413ar https://doi.org/10.4138/atlgeol.2018.002 |
long_lat |
ENVELOPE(141.383,141.383,-66.800,-66.800) ENVELOPE(10.500,10.500,-70.417,-70.417) |
geographic |
Breton Island Canada Mira |
geographic_facet |
Breton Island Canada Mira |
genre |
Breton Island Newfoundland |
genre_facet |
Breton Island Newfoundland |
op_relation |
Atlantic Geology : Journal of the Atlantic Geoscience Society vol. 54 (2018) http://id.erudit.org/iderudit/1055413ar doi:10.4138/atlgeol.2018.002 |
op_rights |
All Rights Reserved ©, 2018Atlantic Geology |
op_doi |
https://doi.org/10.4138/atlgeol.2018.002 |
container_title |
Atlantic Geology |
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021 |
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080 |
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1766381380011294720 |