Age of a K-feldspar megacrystic granite from the Burgeo intrusive suite, and timing of tungsten mineralization at Grey River, southern Newfoundland
A K-feldspar megacrystic biotite granite phase of the Burgeo intrusive suite, southern Newfoundland, has been dated by the Rb–Sr whole-rock method. The isochron age of 412 ± 5 Ma (initial 87 Sr/ 86 Sr ratio = 0.7086 ± 0.0004) is consistent with the younger of two U–Pb zircon ages obtained from other...
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crcansciencepubl:10.1139/e90-092 2023-12-17T10:44:24+01:00 Age of a K-feldspar megacrystic granite from the Burgeo intrusive suite, and timing of tungsten mineralization at Grey River, southern Newfoundland Higgins, N. C. Halliday, A. N. Mitchell, J. G. 1990 http://dx.doi.org/10.1139/e90-092 http://www.nrcresearchpress.com/doi/pdf/10.1139/e90-092 en eng Canadian Science Publishing http://www.nrcresearchpress.com/page/about/CorporateTextAndDataMining Canadian Journal of Earth Sciences volume 27, issue 7, page 893-902 ISSN 0008-4077 1480-3313 General Earth and Planetary Sciences journal-article 1990 crcansciencepubl https://doi.org/10.1139/e90-092 2023-11-19T13:39:26Z A K-feldspar megacrystic biotite granite phase of the Burgeo intrusive suite, southern Newfoundland, has been dated by the Rb–Sr whole-rock method. The isochron age of 412 ± 5 Ma (initial 87 Sr/ 86 Sr ratio = 0.7086 ± 0.0004) is consistent with the younger of two U–Pb zircon ages obtained from other phases of the Burgeo intrusive suite. The southern margin of the granite is intensively deformed in a shear zone that also affects amphibolitic gneisses of the Grey River enclave. Data from deformed granite samples plot below the 412 Ma isochron and may have resulted from reaction and partial reequilibration of the samples with a hydrothermal fluid of low initial 87 Sr/ 86 Sr ratio during metasomatic reactions accompanying shear zone deformation. However, alternative hypotheses such as crustal contamination or derivation from two separate and isotopically distinct magmas cannot be discounted. Mica ages between 390 and 370 Ma associated with tungsten mineralization at Grey River confirm that the mineralization was unrelated to the Burgeo intrusive suite. They support previous conclusions, based on geological and geochemical data, that the mineralization was related to posttectonic leucogranite intrusions. Article in Journal/Newspaper Newfoundland Canadian Science Publishing (via Crossref) Canadian Journal of Earth Sciences 27 7 893 902 |
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Canadian Science Publishing (via Crossref) |
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English |
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General Earth and Planetary Sciences |
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General Earth and Planetary Sciences Higgins, N. C. Halliday, A. N. Mitchell, J. G. Age of a K-feldspar megacrystic granite from the Burgeo intrusive suite, and timing of tungsten mineralization at Grey River, southern Newfoundland |
topic_facet |
General Earth and Planetary Sciences |
description |
A K-feldspar megacrystic biotite granite phase of the Burgeo intrusive suite, southern Newfoundland, has been dated by the Rb–Sr whole-rock method. The isochron age of 412 ± 5 Ma (initial 87 Sr/ 86 Sr ratio = 0.7086 ± 0.0004) is consistent with the younger of two U–Pb zircon ages obtained from other phases of the Burgeo intrusive suite. The southern margin of the granite is intensively deformed in a shear zone that also affects amphibolitic gneisses of the Grey River enclave. Data from deformed granite samples plot below the 412 Ma isochron and may have resulted from reaction and partial reequilibration of the samples with a hydrothermal fluid of low initial 87 Sr/ 86 Sr ratio during metasomatic reactions accompanying shear zone deformation. However, alternative hypotheses such as crustal contamination or derivation from two separate and isotopically distinct magmas cannot be discounted. Mica ages between 390 and 370 Ma associated with tungsten mineralization at Grey River confirm that the mineralization was unrelated to the Burgeo intrusive suite. They support previous conclusions, based on geological and geochemical data, that the mineralization was related to posttectonic leucogranite intrusions. |
format |
Article in Journal/Newspaper |
author |
Higgins, N. C. Halliday, A. N. Mitchell, J. G. |
author_facet |
Higgins, N. C. Halliday, A. N. Mitchell, J. G. |
author_sort |
Higgins, N. C. |
title |
Age of a K-feldspar megacrystic granite from the Burgeo intrusive suite, and timing of tungsten mineralization at Grey River, southern Newfoundland |
title_short |
Age of a K-feldspar megacrystic granite from the Burgeo intrusive suite, and timing of tungsten mineralization at Grey River, southern Newfoundland |
title_full |
Age of a K-feldspar megacrystic granite from the Burgeo intrusive suite, and timing of tungsten mineralization at Grey River, southern Newfoundland |
title_fullStr |
Age of a K-feldspar megacrystic granite from the Burgeo intrusive suite, and timing of tungsten mineralization at Grey River, southern Newfoundland |
title_full_unstemmed |
Age of a K-feldspar megacrystic granite from the Burgeo intrusive suite, and timing of tungsten mineralization at Grey River, southern Newfoundland |
title_sort |
age of a k-feldspar megacrystic granite from the burgeo intrusive suite, and timing of tungsten mineralization at grey river, southern newfoundland |
publisher |
Canadian Science Publishing |
publishDate |
1990 |
url |
http://dx.doi.org/10.1139/e90-092 http://www.nrcresearchpress.com/doi/pdf/10.1139/e90-092 |
genre |
Newfoundland |
genre_facet |
Newfoundland |
op_source |
Canadian Journal of Earth Sciences volume 27, issue 7, page 893-902 ISSN 0008-4077 1480-3313 |
op_rights |
http://www.nrcresearchpress.com/page/about/CorporateTextAndDataMining |
op_doi |
https://doi.org/10.1139/e90-092 |
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Canadian Journal of Earth Sciences |
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27 |
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7 |
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893 |
op_container_end_page |
902 |
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1785562218919624704 |