The origin of mafic-ultramafic bodies within the northern Dashwoods Subzone, Newfoundland Appalachians
Mafic-ultramafic bodies of possible ophiolitic origin are widespread within the northern part of the Dashwoods Subzone of the Newfoundland Appalachians. The bodies fall into two types; the first consists of relatively undeformed, fresh, layered gabbroic bodies, which contrasts with the second that cons...
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Atlantic Geoscience Society
2006
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ftuninewbrunojs:oai:ojs.journals.lib.unb.ca:article/2152 2023-05-15T17:22:02+02:00 The origin of mafic-ultramafic bodies within the northern Dashwoods Subzone, Newfoundland Appalachians Lissenberg, C. Johan McNicoll, Vicki J. van Staal, Cess R. 2006-04-01 text/html application/pdf https://journals.lib.unb.ca/index.php/ag/article/view/2152 eng eng Atlantic Geoscience Society https://journals.lib.unb.ca/index.php/ag/article/view/2152/2532 https://journals.lib.unb.ca/index.php/ag/article/view/2152/2533 https://journals.lib.unb.ca/index.php/ag/article/view/2152 Copyright (c) 2015 Atlantic Geology Atlantic Geoscience; Vol. 42 No. 1 (2006) 2564-2987 info:eu-repo/semantics/article info:eu-repo/semantics/publishedVersion research-article 2006 ftuninewbrunojs 2022-07-11T11:41:57Z Mafic-ultramafic bodies of possible ophiolitic origin are widespread within the northern part of the Dashwoods Subzone of the Newfoundland Appalachians. The bodies fall into two types; the first consists of relatively undeformed, fresh, layered gabbroic bodies, which contrasts with the second that consists of metamorphosed ultramafic lithologies. Two of the largest gabbroic bodies yielded U-Pb zircon ages of 432.4±1.0 and 429.9±1.2 Ma. Their Silurian age refutes an ophiolitic origin, and, along with their hydrous nature and fresh character, indicates that they formed in the widespread Early Silurian igneous event that affected both the Dashwoods and Notre Dame subzones. Our new data further substantiate the bimodal character of the Silurian event. The ultramafic bodies are inferred to be of ophiolitic origin. Those that occur in the Dashwoods subzone are interpreted to be related to the Lushs Bight oceanic tract, whereas those in the Lloyds River Fault Zone are correlated with the Annieopsquotch ophiolite belt. RÉSUMÉ Des masses mafiques-ultramafiques d’origine possiblement ophiolitique sont répandues à l’intérieur de la partie septentrionale de la sous-zone de Dashwoods des Appalaches à Terre-Neuve. Les masses s’insèrent dans deux catégories: la première est constituée de masses gabbroïques stratifiées, récentes, relativement peu déformées, qui tranchent avec la seconde, constituée de lithologies ultramafiques métamorphisées. Deux des masses gabbroïques les plus vastes ont affiché des âges de 432,4 ±1,0 et de 429,9 ±1,2 Ma par datation U-Pb sur zircon. Leur âge silurien réfute une origine ophiolitique et, de pair avec leur nature aqueuse et leur caractère récent, signale qu’elles se sont formées au cours du processus igné étendu du Silurien précoce ayant affecté les sous-zones de Dashwoods et de Notre Dame. Nos nouvelles données attestent davantage le caractère bimodal de l’événement silurien. On suppose que les masses ultramafiques sont d’origine ophiolitique. Les masses présentes dans la sous-zone de Dashwoods sont ... Article in Journal/Newspaper Newfoundland Terre-Neuve University of New Brunswick: Centre for Digital Scholarship Journals Atlantic Geology 42 1 |
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University of New Brunswick: Centre for Digital Scholarship Journals |
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ftuninewbrunojs |
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English |
description |
Mafic-ultramafic bodies of possible ophiolitic origin are widespread within the northern part of the Dashwoods Subzone of the Newfoundland Appalachians. The bodies fall into two types; the first consists of relatively undeformed, fresh, layered gabbroic bodies, which contrasts with the second that consists of metamorphosed ultramafic lithologies. Two of the largest gabbroic bodies yielded U-Pb zircon ages of 432.4±1.0 and 429.9±1.2 Ma. Their Silurian age refutes an ophiolitic origin, and, along with their hydrous nature and fresh character, indicates that they formed in the widespread Early Silurian igneous event that affected both the Dashwoods and Notre Dame subzones. Our new data further substantiate the bimodal character of the Silurian event. The ultramafic bodies are inferred to be of ophiolitic origin. Those that occur in the Dashwoods subzone are interpreted to be related to the Lushs Bight oceanic tract, whereas those in the Lloyds River Fault Zone are correlated with the Annieopsquotch ophiolite belt. RÉSUMÉ Des masses mafiques-ultramafiques d’origine possiblement ophiolitique sont répandues à l’intérieur de la partie septentrionale de la sous-zone de Dashwoods des Appalaches à Terre-Neuve. Les masses s’insèrent dans deux catégories: la première est constituée de masses gabbroïques stratifiées, récentes, relativement peu déformées, qui tranchent avec la seconde, constituée de lithologies ultramafiques métamorphisées. Deux des masses gabbroïques les plus vastes ont affiché des âges de 432,4 ±1,0 et de 429,9 ±1,2 Ma par datation U-Pb sur zircon. Leur âge silurien réfute une origine ophiolitique et, de pair avec leur nature aqueuse et leur caractère récent, signale qu’elles se sont formées au cours du processus igné étendu du Silurien précoce ayant affecté les sous-zones de Dashwoods et de Notre Dame. Nos nouvelles données attestent davantage le caractère bimodal de l’événement silurien. On suppose que les masses ultramafiques sont d’origine ophiolitique. Les masses présentes dans la sous-zone de Dashwoods sont ... |
format |
Article in Journal/Newspaper |
author |
Lissenberg, C. Johan McNicoll, Vicki J. van Staal, Cess R. |
spellingShingle |
Lissenberg, C. Johan McNicoll, Vicki J. van Staal, Cess R. The origin of mafic-ultramafic bodies within the northern Dashwoods Subzone, Newfoundland Appalachians |
author_facet |
Lissenberg, C. Johan McNicoll, Vicki J. van Staal, Cess R. |
author_sort |
Lissenberg, C. Johan |
title |
The origin of mafic-ultramafic bodies within the northern Dashwoods Subzone, Newfoundland Appalachians |
title_short |
The origin of mafic-ultramafic bodies within the northern Dashwoods Subzone, Newfoundland Appalachians |
title_full |
The origin of mafic-ultramafic bodies within the northern Dashwoods Subzone, Newfoundland Appalachians |
title_fullStr |
The origin of mafic-ultramafic bodies within the northern Dashwoods Subzone, Newfoundland Appalachians |
title_full_unstemmed |
The origin of mafic-ultramafic bodies within the northern Dashwoods Subzone, Newfoundland Appalachians |
title_sort |
origin of mafic-ultramafic bodies within the northern dashwoods subzone, newfoundland appalachians |
publisher |
Atlantic Geoscience Society |
publishDate |
2006 |
url |
https://journals.lib.unb.ca/index.php/ag/article/view/2152 |
genre |
Newfoundland Terre-Neuve |
genre_facet |
Newfoundland Terre-Neuve |
op_source |
Atlantic Geoscience; Vol. 42 No. 1 (2006) 2564-2987 |
op_relation |
https://journals.lib.unb.ca/index.php/ag/article/view/2152/2532 https://journals.lib.unb.ca/index.php/ag/article/view/2152/2533 https://journals.lib.unb.ca/index.php/ag/article/view/2152 |
op_rights |
Copyright (c) 2015 Atlantic Geology |
container_title |
Atlantic Geology |
container_volume |
42 |
container_issue |
1 |
_version_ |
1766108282196328448 |