Lithogeochemical, isotopic, and U–Pb (zircon) age constraints on arc to rift magmatism, northwestern and central Avalon Terrane, Newfoundland, Canada: implications for local lithostratigraphy
The northwestern Avalon Terrane, Newfoundland, is underlain by Neoproterozoic rocks traditionally divided into older Love Cove Group, medial Connecting Point Group, and the unconformably overlying Musgravetown Group. New lithogeochemical, isotopic, and updated U–Pb (zircon) age data demand changes t...
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crcansciencepubl:10.1139/cjes-2019-0196 2024-09-15T18:20:02+00:00 Lithogeochemical, isotopic, and U–Pb (zircon) age constraints on arc to rift magmatism, northwestern and central Avalon Terrane, Newfoundland, Canada: implications for local lithostratigraphy Mills, Andrea J. Dunning, Greg R. Sandeman, Hamish A. 2021 http://dx.doi.org/10.1139/cjes-2019-0196 https://cdnsciencepub.com/doi/full-xml/10.1139/cjes-2019-0196 https://cdnsciencepub.com/doi/pdf/10.1139/cjes-2019-0196 en eng Canadian Science Publishing http://www.nrcresearchpress.com/page/about/CorporateTextAndDataMining Canadian Journal of Earth Sciences volume 58, issue 4, page 332-354 ISSN 0008-4077 1480-3313 journal-article 2021 crcansciencepubl https://doi.org/10.1139/cjes-2019-0196 2024-08-01T04:10:04Z The northwestern Avalon Terrane, Newfoundland, is underlain by Neoproterozoic rocks traditionally divided into older Love Cove Group, medial Connecting Point Group, and the unconformably overlying Musgravetown Group. New lithogeochemical, isotopic, and updated U–Pb (zircon) age data demand changes to stratigraphic nomenclature and maps and help constrain the tectonomagmatic evolution. U–Pb age constraints include 620 ± 2 Ma for the calc-alkaline Broad Island Group (former Love Cove Group); 605 ± 1.2 Ma for rhyolite from near Bull Arm (type area, Bull Arm Formation, lower Musgravetown Group); 589 ± 2.0 Ma for a schist from the Love Cove type locality; 568.7 ± 1.4 Ma for rhyolite of the Rocky Harbour Formation, upper Musgravetown Group; and 572 ± 2 Ma for Louil Hills granite. In light of these results, remnants of the main Avalonian arc are re-designated “Broad Island Group”, for the site of the dated 620 Ma tuff. The ca. 589 Ma schist from Love Cove is included in the Musgravetown Group and may be a tectonized equivalent of Bull Arm Formation. Our data outline a tectonomagmatic change from arc-dominated magmatism at ca. 620 Ma, to an extensional regime ca. 605–589 Ma, culminating in alkaline magmatism by ca. 572 Ma. εNd t values (t = 620–569 Ma) for felsic rocks range from 3.7 to 5.6 and yield T DM ages consistent with derivation from a juvenile Neoproterozoic (878–730 Ma) basement. Mafic rocks exhibit a time-progressive increase in εNd t , indicating more juvenile mantle sources through time. Further delimitation of map units of the area await integrated lithostratigraphy, precise modern U–Pb geochronology, and lithogeochemistry. Article in Journal/Newspaper Newfoundland Canadian Science Publishing Canadian Journal of Earth Sciences 58 4 332 354 |
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Canadian Science Publishing |
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English |
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The northwestern Avalon Terrane, Newfoundland, is underlain by Neoproterozoic rocks traditionally divided into older Love Cove Group, medial Connecting Point Group, and the unconformably overlying Musgravetown Group. New lithogeochemical, isotopic, and updated U–Pb (zircon) age data demand changes to stratigraphic nomenclature and maps and help constrain the tectonomagmatic evolution. U–Pb age constraints include 620 ± 2 Ma for the calc-alkaline Broad Island Group (former Love Cove Group); 605 ± 1.2 Ma for rhyolite from near Bull Arm (type area, Bull Arm Formation, lower Musgravetown Group); 589 ± 2.0 Ma for a schist from the Love Cove type locality; 568.7 ± 1.4 Ma for rhyolite of the Rocky Harbour Formation, upper Musgravetown Group; and 572 ± 2 Ma for Louil Hills granite. In light of these results, remnants of the main Avalonian arc are re-designated “Broad Island Group”, for the site of the dated 620 Ma tuff. The ca. 589 Ma schist from Love Cove is included in the Musgravetown Group and may be a tectonized equivalent of Bull Arm Formation. Our data outline a tectonomagmatic change from arc-dominated magmatism at ca. 620 Ma, to an extensional regime ca. 605–589 Ma, culminating in alkaline magmatism by ca. 572 Ma. εNd t values (t = 620–569 Ma) for felsic rocks range from 3.7 to 5.6 and yield T DM ages consistent with derivation from a juvenile Neoproterozoic (878–730 Ma) basement. Mafic rocks exhibit a time-progressive increase in εNd t , indicating more juvenile mantle sources through time. Further delimitation of map units of the area await integrated lithostratigraphy, precise modern U–Pb geochronology, and lithogeochemistry. |
format |
Article in Journal/Newspaper |
author |
Mills, Andrea J. Dunning, Greg R. Sandeman, Hamish A. |
spellingShingle |
Mills, Andrea J. Dunning, Greg R. Sandeman, Hamish A. Lithogeochemical, isotopic, and U–Pb (zircon) age constraints on arc to rift magmatism, northwestern and central Avalon Terrane, Newfoundland, Canada: implications for local lithostratigraphy |
author_facet |
Mills, Andrea J. Dunning, Greg R. Sandeman, Hamish A. |
author_sort |
Mills, Andrea J. |
title |
Lithogeochemical, isotopic, and U–Pb (zircon) age constraints on arc to rift magmatism, northwestern and central Avalon Terrane, Newfoundland, Canada: implications for local lithostratigraphy |
title_short |
Lithogeochemical, isotopic, and U–Pb (zircon) age constraints on arc to rift magmatism, northwestern and central Avalon Terrane, Newfoundland, Canada: implications for local lithostratigraphy |
title_full |
Lithogeochemical, isotopic, and U–Pb (zircon) age constraints on arc to rift magmatism, northwestern and central Avalon Terrane, Newfoundland, Canada: implications for local lithostratigraphy |
title_fullStr |
Lithogeochemical, isotopic, and U–Pb (zircon) age constraints on arc to rift magmatism, northwestern and central Avalon Terrane, Newfoundland, Canada: implications for local lithostratigraphy |
title_full_unstemmed |
Lithogeochemical, isotopic, and U–Pb (zircon) age constraints on arc to rift magmatism, northwestern and central Avalon Terrane, Newfoundland, Canada: implications for local lithostratigraphy |
title_sort |
lithogeochemical, isotopic, and u–pb (zircon) age constraints on arc to rift magmatism, northwestern and central avalon terrane, newfoundland, canada: implications for local lithostratigraphy |
publisher |
Canadian Science Publishing |
publishDate |
2021 |
url |
http://dx.doi.org/10.1139/cjes-2019-0196 https://cdnsciencepub.com/doi/full-xml/10.1139/cjes-2019-0196 https://cdnsciencepub.com/doi/pdf/10.1139/cjes-2019-0196 |
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Newfoundland |
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Newfoundland |
op_source |
Canadian Journal of Earth Sciences volume 58, issue 4, page 332-354 ISSN 0008-4077 1480-3313 |
op_rights |
http://www.nrcresearchpress.com/page/about/CorporateTextAndDataMining |
op_doi |
https://doi.org/10.1139/cjes-2019-0196 |
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Canadian Journal of Earth Sciences |
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58 |
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4 |
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332 |
op_container_end_page |
354 |
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1810458408259682304 |