Precambrian in the external zones o f the Variscides: central and northern parts o f the Armorican Massif

Abstract : Precambrian in the external zones o f the Variscides Cadomian tectonic effects appear relatively minor and are seen to diminish in importance as one goes towards the south and east away from the Domnonean ‘Cordillera’ (ridge). The deformation style of these external parts of the Cadomian chain is characterized by a lack of cleavage and a development of synsedimentary breccias and superficial recumbent folds produced by local sliding over an unknown basement. Both the Brioverian and its Palaeozoic cover are actively affected by Hercynian deformation; in fact, most of the schistosity developed in the Brioverian of Central Brittany relates to Variscan orogenesis. The southern limit of the domain is marked by the northerp branch of the South Armorican Shear Zone, which is itself guided by the Canvaux granitic-gneiss belt. Intrusives along this axis have Ordovician and Silurian ages and appear as the first signs of crustal distension that, further south, characterizes the early stages in the evolution of the Ligerian active margin.
Type de document :
Autre publication
MA0134. Tiré-à-part. 1988, pp.414-434
Liste complète des métadonnées

Littérature citée [43 références]  Voir  Masquer  Télécharger

https://hal-insu.archives-ouvertes.fr/insu-01538316
Contributeur : Isabelle Dubigeon <>
Soumis le : mardi 13 juin 2017 - 13:44:04
Dernière modification le : mardi 5 juin 2018 - 10:14:24
Document(s) archivé(s) le : mardi 12 décembre 2017 - 16:22:34

Fichier

MA0134-Cogné.pdf
Fichiers éditeurs autorisés sur une archive ouverte

Identifiants

  • HAL Id : insu-01538316, version 1

Collections

Citation

Jean Cogné, Bernard Auvray, Lionel Dupret, Jean-Jacques Chauvel, Dominique Rabu. Precambrian in the external zones o f the Variscides: central and northern parts o f the Armorican Massif. MA0134. Tiré-à-part. 1988, pp.414-434. 〈insu-01538316〉

Partager

Métriques

Consultations de la notice

66

Téléchargements de fichiers

60