The Yellowknife greenstone belt and underlying Central Slave Cover Group, Slave craton, Canada: constraints and questions arising from a U–Pb dating study
Legacy U–Pb isotopic data are reported for the Mesoarchean Central Slave Cover Group and Neoarchean Yellowknife greenstone belt, Slave craton, Northwest Territories, Canada. In two locations north of the City of Yellowknife, exposures of cover group rocks occur beneath mafic volcanic and subvolcanic...
Published in: | Canadian Journal of Earth Sciences |
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2024
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Online Access: | http://dx.doi.org/10.1139/cjes-2024-0028 https://cdnsciencepub.com/doi/full-xml/10.1139/cjes-2024-0028 https://cdnsciencepub.com/doi/pdf/10.1139/cjes-2024-0028 |
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crcansciencepubl:10.1139/cjes-2024-0028 2024-09-30T14:40:27+00:00 The Yellowknife greenstone belt and underlying Central Slave Cover Group, Slave craton, Canada: constraints and questions arising from a U–Pb dating study Ketchum, John W.F. Bleeker, Wouter Falck, Hendrik Jackson, Valerie A. 2024 http://dx.doi.org/10.1139/cjes-2024-0028 https://cdnsciencepub.com/doi/full-xml/10.1139/cjes-2024-0028 https://cdnsciencepub.com/doi/pdf/10.1139/cjes-2024-0028 en eng Canadian Science Publishing http://www.nrcresearchpress.com/page/about/CorporateTextAndDataMining Canadian Journal of Earth Sciences ISSN 0008-4077 1480-3313 journal-article 2024 crcansciencepubl https://doi.org/10.1139/cjes-2024-0028 2024-09-19T04:09:48Z Legacy U–Pb isotopic data are reported for the Mesoarchean Central Slave Cover Group and Neoarchean Yellowknife greenstone belt, Slave craton, Northwest Territories, Canada. In two locations north of the City of Yellowknife, exposures of cover group rocks occur beneath mafic volcanic and subvolcanic units traditionally assigned to the basal Chan Formation of the Kam Group. Both cover group occurrences contain felsic volcanic tuff units that yield eruption ages of 2853 + 2/−1.5 Ma and 2826 ± 1.5 Ma. The younger tuff is underlain by felsic volcaniclastic schist with a dominant, basement-aged detrital zircon population that was deposited after 2840 ± 6 Ma. Near the south end of the exposed greenstone belt, a felsic tuff within the Octopus Formation provides an age of 2699 ± 3 Ma, confirming that this formation is not part of the Central Slave Cover Group. A pillowed basalt flow within the Chan Formation is cut by a composite gabbro dyke dated as 2738 +3.5/−3 Ma. However, a more general ca. 2730–2740 Ma age interpretation for this dyke may be appropriate due to the potential for complex lead loss behaviour in the dated baddeleyite fractions. Younger U–Pb zircon and monazite ages reported herein (2710–2706 Ma) contribute to our understanding of felsic magmatic and gold-mineralizing events that influenced later development of the Yellowknife greenstone belt. Although the depositional history of the autochthonous Central Slave Cover Group is becoming better known, questions remain regarding the age and tectonomagmatic affinity of adjacent mafic volcanic rocks traditionally assigned to the Kam Group and correlative assemblages. Are some of these rocks actually part of the Central Slave Cover Group? Article in Journal/Newspaper Northwest Territories Yellowknife Canadian Science Publishing Canada Northwest Territories Yellowknife Canadian Journal of Earth Sciences |
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Canadian Science Publishing |
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crcansciencepubl |
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English |
description |
Legacy U–Pb isotopic data are reported for the Mesoarchean Central Slave Cover Group and Neoarchean Yellowknife greenstone belt, Slave craton, Northwest Territories, Canada. In two locations north of the City of Yellowknife, exposures of cover group rocks occur beneath mafic volcanic and subvolcanic units traditionally assigned to the basal Chan Formation of the Kam Group. Both cover group occurrences contain felsic volcanic tuff units that yield eruption ages of 2853 + 2/−1.5 Ma and 2826 ± 1.5 Ma. The younger tuff is underlain by felsic volcaniclastic schist with a dominant, basement-aged detrital zircon population that was deposited after 2840 ± 6 Ma. Near the south end of the exposed greenstone belt, a felsic tuff within the Octopus Formation provides an age of 2699 ± 3 Ma, confirming that this formation is not part of the Central Slave Cover Group. A pillowed basalt flow within the Chan Formation is cut by a composite gabbro dyke dated as 2738 +3.5/−3 Ma. However, a more general ca. 2730–2740 Ma age interpretation for this dyke may be appropriate due to the potential for complex lead loss behaviour in the dated baddeleyite fractions. Younger U–Pb zircon and monazite ages reported herein (2710–2706 Ma) contribute to our understanding of felsic magmatic and gold-mineralizing events that influenced later development of the Yellowknife greenstone belt. Although the depositional history of the autochthonous Central Slave Cover Group is becoming better known, questions remain regarding the age and tectonomagmatic affinity of adjacent mafic volcanic rocks traditionally assigned to the Kam Group and correlative assemblages. Are some of these rocks actually part of the Central Slave Cover Group? |
format |
Article in Journal/Newspaper |
author |
Ketchum, John W.F. Bleeker, Wouter Falck, Hendrik Jackson, Valerie A. |
spellingShingle |
Ketchum, John W.F. Bleeker, Wouter Falck, Hendrik Jackson, Valerie A. The Yellowknife greenstone belt and underlying Central Slave Cover Group, Slave craton, Canada: constraints and questions arising from a U–Pb dating study |
author_facet |
Ketchum, John W.F. Bleeker, Wouter Falck, Hendrik Jackson, Valerie A. |
author_sort |
Ketchum, John W.F. |
title |
The Yellowknife greenstone belt and underlying Central Slave Cover Group, Slave craton, Canada: constraints and questions arising from a U–Pb dating study |
title_short |
The Yellowknife greenstone belt and underlying Central Slave Cover Group, Slave craton, Canada: constraints and questions arising from a U–Pb dating study |
title_full |
The Yellowknife greenstone belt and underlying Central Slave Cover Group, Slave craton, Canada: constraints and questions arising from a U–Pb dating study |
title_fullStr |
The Yellowknife greenstone belt and underlying Central Slave Cover Group, Slave craton, Canada: constraints and questions arising from a U–Pb dating study |
title_full_unstemmed |
The Yellowknife greenstone belt and underlying Central Slave Cover Group, Slave craton, Canada: constraints and questions arising from a U–Pb dating study |
title_sort |
yellowknife greenstone belt and underlying central slave cover group, slave craton, canada: constraints and questions arising from a u–pb dating study |
publisher |
Canadian Science Publishing |
publishDate |
2024 |
url |
http://dx.doi.org/10.1139/cjes-2024-0028 https://cdnsciencepub.com/doi/full-xml/10.1139/cjes-2024-0028 https://cdnsciencepub.com/doi/pdf/10.1139/cjes-2024-0028 |
geographic |
Canada Northwest Territories Yellowknife |
geographic_facet |
Canada Northwest Territories Yellowknife |
genre |
Northwest Territories Yellowknife |
genre_facet |
Northwest Territories Yellowknife |
op_source |
Canadian Journal of Earth Sciences ISSN 0008-4077 1480-3313 |
op_rights |
http://www.nrcresearchpress.com/page/about/CorporateTextAndDataMining |
op_doi |
https://doi.org/10.1139/cjes-2024-0028 |
container_title |
Canadian Journal of Earth Sciences |
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1811642928014032896 |