Abstract

Three main geological units are distinguished in the Mount McGerrigle area of north-central Gaspé, each different in lithology, structural style, and age: a Cambro-Ordovician, complexly deformed assemblage of eugeosynclinal rocks is discordantly intruded by a composite pluton, and is unconformably overlain by mildly deformed Silurian–Devonian platform deposits. Three phases of deformation (F1, F2, F3) have affected the Quebec and Schickshock Groups of Cambro-Ordovidian age. The F1, deformation was accompanied by lowgrade regional metamorphism resulting in a penetrative planar fabric. The F2 deformation deformed pre-existing structures and produced the prevalent northeasterly trending and shallowly plunging folds. The third phase was least penetrative, resulting in broad and upright east-northeasterly striking F3 folds that modify the orientation of F2 structures. The forcefully injected Mount McGerrigle pluton, a late intrusion of the Acadian orogeny, truncates and deforms the F1 and F2 fabric elements of the Cambro-Ordovician rock. Multiphase deformation thus preceded the Acadian orogeny in the area. Silurian–Devonian rocks, on the other hand, have been affected only by the F3 deformation during the Acadian orogeny.

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.