The Acadian Orogeny: Recent Studies in New England, Maritime Canada, and the Autochthonous Foreland
Acadian deformations in the southwestern Quebec Appalachians
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Published:January 01, 1993
Regional deformation encountered in Ordovician rocks of the Ascot Complex and the Magog Group of the Dunnage zone is synchronous with the development of the La Guadeloupe fault. Structural analysis indicates that along most of the length of this fault, Silurian and Devonian rocks of the Saint-Francis Group were thrust over the Dunnage zone and its post-Ordovician cover sequence. Structural fabrics of these units are thus related to the Acadian Orogeny, and pre-Acadian deformations are of much less importance.
Major Acadian faults in the northeastern part of the Québec Appalachians are dextral strike-slip faults, whereas they are largely thrust faults in its southwestern parts. The northern part of the Beauce area lies within the transition zone between these two fault regimes. Transected folds on both sides of the La Guadeloupe fault suggest a dextral oblique-slip tectonic transport. Northwest of the Magog Group, Upper Silurian rocks of the Cranbourne Formation unconformably overlie the Baie Verte-Brompton Line. The Cranbourne Formation is folded and cut by the same regional cleavage as the rocks below the unconformity. This demonstrates that the Acadian Orogeny is the major regional phase of deformation of all these units.
- Acadian Phase
- Appalachians
- Canada
- cleavage
- deformation
- Devonian
- Dunnage Zone
- Eastern Canada
- evolution
- fabric
- faults
- folds
- kinematics
- lateral faults
- North America
- Paleozoic
- Quebec
- right-lateral faults
- Sherbrooke County Quebec
- strike-slip faults
- thrust faults
- unconformities
- southwestern Quebec
- Magog Group
- Ascot Complex
- Saint Francis Group
- La Guadeloupe Fault