Magmatisme fissural triasico-liasique dans l'ouest du Massif armoricain (France): pétrologie, géochimie, âge, et modalités de la mise en place
The dolerite dykes at the western end of Britanny (France), which is located on the North Atlantic margin, were emplaced in a NW–SE field of faults at the Trias–Lias time limit, between 210 and 195 Ma. These rocks are quartz tholeiites enriched in TiO 2 , with a trace element composition close to th...
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crcansciencepubl:10.1139/e95-147 2024-09-15T18:22:49+00:00 Magmatisme fissural triasico-liasique dans l'ouest du Massif armoricain (France): pétrologie, géochimie, âge, et modalités de la mise en place Caroff, Martial Bellon, Hervé Chauris, Louis Carron, Jean-Paul Chevrier, Stéphane Gardinier, Alain Cotten, Joseph Moan, Yann Le Neidhart, Yseult 1995 http://dx.doi.org/10.1139/e95-147 http://www.nrcresearchpress.com/doi/pdf/10.1139/e95-147 en eng Canadian Science Publishing http://www.nrcresearchpress.com/page/about/CorporateTextAndDataMining Canadian Journal of Earth Sciences volume 32, issue 11, page 1921-1936 ISSN 0008-4077 1480-3313 journal-article 1995 crcansciencepubl https://doi.org/10.1139/e95-147 2024-07-25T04:10:08Z The dolerite dykes at the western end of Britanny (France), which is located on the North Atlantic margin, were emplaced in a NW–SE field of faults at the Trias–Lias time limit, between 210 and 195 Ma. These rocks are quartz tholeiites enriched in TiO 2 , with a trace element composition close to that of the Deccan basalts. The initial concentrations of Ba, K, and Rb, though slightly modified by the alteration, and of Nb seem to have been affected by crustal contamination during the magma transfer. These dykes are comparable, in age and composition, to the tholeiitic dykes exposed in the Iberian Peninsula, in the Moroccan Atlas and in the Northern Appalachians; they however have a different orientation. Furthermore, these various domains differ in their postintrusion history: the rifting leading to the opening of the Central Atlantic occurred soon after the intrusions of the dykes, whereas the opening of the North Atlantic began several tens of millions of years later, following the direction of the Armorican array of dykes. The study of the mode of emplacement of the intrusions shows evidence of two sets of dykes: "simple dikes", 5 to 10 m thick, resulting from a single magmatic injection and "multiple dykes", about 30 m thick, composed of five magmatic units that are individually 5 to 10 m wide. The western Armorican dyke field is the result of the intrusion of successive sets of dolerite having a uniform thickness and composition, suggesting a cyclic magmatic supply from homogeneous source. [Journal Translation] Article in Journal/Newspaper North Atlantic Canadian Science Publishing Canadian Journal of Earth Sciences 32 11 1921 1936 |
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Open Polar |
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Canadian Science Publishing |
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crcansciencepubl |
language |
English |
description |
The dolerite dykes at the western end of Britanny (France), which is located on the North Atlantic margin, were emplaced in a NW–SE field of faults at the Trias–Lias time limit, between 210 and 195 Ma. These rocks are quartz tholeiites enriched in TiO 2 , with a trace element composition close to that of the Deccan basalts. The initial concentrations of Ba, K, and Rb, though slightly modified by the alteration, and of Nb seem to have been affected by crustal contamination during the magma transfer. These dykes are comparable, in age and composition, to the tholeiitic dykes exposed in the Iberian Peninsula, in the Moroccan Atlas and in the Northern Appalachians; they however have a different orientation. Furthermore, these various domains differ in their postintrusion history: the rifting leading to the opening of the Central Atlantic occurred soon after the intrusions of the dykes, whereas the opening of the North Atlantic began several tens of millions of years later, following the direction of the Armorican array of dykes. The study of the mode of emplacement of the intrusions shows evidence of two sets of dykes: "simple dikes", 5 to 10 m thick, resulting from a single magmatic injection and "multiple dykes", about 30 m thick, composed of five magmatic units that are individually 5 to 10 m wide. The western Armorican dyke field is the result of the intrusion of successive sets of dolerite having a uniform thickness and composition, suggesting a cyclic magmatic supply from homogeneous source. [Journal Translation] |
format |
Article in Journal/Newspaper |
author |
Caroff, Martial Bellon, Hervé Chauris, Louis Carron, Jean-Paul Chevrier, Stéphane Gardinier, Alain Cotten, Joseph Moan, Yann Le Neidhart, Yseult |
spellingShingle |
Caroff, Martial Bellon, Hervé Chauris, Louis Carron, Jean-Paul Chevrier, Stéphane Gardinier, Alain Cotten, Joseph Moan, Yann Le Neidhart, Yseult Magmatisme fissural triasico-liasique dans l'ouest du Massif armoricain (France): pétrologie, géochimie, âge, et modalités de la mise en place |
author_facet |
Caroff, Martial Bellon, Hervé Chauris, Louis Carron, Jean-Paul Chevrier, Stéphane Gardinier, Alain Cotten, Joseph Moan, Yann Le Neidhart, Yseult |
author_sort |
Caroff, Martial |
title |
Magmatisme fissural triasico-liasique dans l'ouest du Massif armoricain (France): pétrologie, géochimie, âge, et modalités de la mise en place |
title_short |
Magmatisme fissural triasico-liasique dans l'ouest du Massif armoricain (France): pétrologie, géochimie, âge, et modalités de la mise en place |
title_full |
Magmatisme fissural triasico-liasique dans l'ouest du Massif armoricain (France): pétrologie, géochimie, âge, et modalités de la mise en place |
title_fullStr |
Magmatisme fissural triasico-liasique dans l'ouest du Massif armoricain (France): pétrologie, géochimie, âge, et modalités de la mise en place |
title_full_unstemmed |
Magmatisme fissural triasico-liasique dans l'ouest du Massif armoricain (France): pétrologie, géochimie, âge, et modalités de la mise en place |
title_sort |
magmatisme fissural triasico-liasique dans l'ouest du massif armoricain (france): pétrologie, géochimie, âge, et modalités de la mise en place |
publisher |
Canadian Science Publishing |
publishDate |
1995 |
url |
http://dx.doi.org/10.1139/e95-147 http://www.nrcresearchpress.com/doi/pdf/10.1139/e95-147 |
genre |
North Atlantic |
genre_facet |
North Atlantic |
op_source |
Canadian Journal of Earth Sciences volume 32, issue 11, page 1921-1936 ISSN 0008-4077 1480-3313 |
op_rights |
http://www.nrcresearchpress.com/page/about/CorporateTextAndDataMining |
op_doi |
https://doi.org/10.1139/e95-147 |
container_title |
Canadian Journal of Earth Sciences |
container_volume |
32 |
container_issue |
11 |
container_start_page |
1921 |
op_container_end_page |
1936 |
_version_ |
1810462826261643264 |