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TitreNeoproterozoic deformation in eastern Mackenzie Mountains and Mackenzie Plain, Northwest Territories
AuteurFallas, K M; MacLean, B C; MacNaughton, R B
Source 2017 p. 25-26
LiensOnline - En ligne (1.7 MB)
Année2017
Séries alt.Ressources naturelles Canada, Contribution externe 20170253
ÉditeurCommission géologique des Territoires du Nord-Ouest
RéunionYellowknife Geoscience Forum; Yellowknife; CA; Novembre 14-16, 2017
Documentpublication en série
Lang.anglais
Mediapapier; en ligne; numérique
Formatspdf
ProvinceTerritoires du Nord-Ouest
Sujetssedimentation; interpretations sismiques; levés de reflexion sismiques; levés sismiques, sol; plissement; géologie du substratum rocheux; discordances; modèles stratigraphiques; Supergroupe de Mackenzie Mountains ; Groupe de Coates Lake ; stratigraphie; géologie régional
ProgrammeGéo-transect Shield à Selwyn, sous-projet Mackenzie-Selwyn du corridor de Mackenzie, GEM2 : La géocartographie de l'énergie et des minéraux
Résumé(disponible en anglais seulement)
Bedrock mapping and reflection seismic interpretation, conducted as part of the Geological Survey of Canada¿s Mackenzie Project of the GEM program, has documented a regional folding event affecting Tonian strata of the Mackenzie Mountains Supergroup (MMSG), Coates Lake Group, and their lateral equivalents (Hematite Creek Group and Shaler Supergroup). The area definitely affected by folding includes the eastern Mackenzie Mountains and central Mackenzie Plain, approximately 300 km x 500 km, but folding may extend beyond this region. This folding event does not involve Cryogenian to Cambrian strata unconformably overlying the MMSG. In western and central Mackenzie Mountains, stratigraphic constraints suggest the folding occurred between deposition of the Coates Lake Group and deposition of the overlying Rapitan Group, between 732 and 717 Ma based on current dating of these units. The broad, regional folds have wavelengths from 30 to 100 km, and amplitudes of 2-3 km, and are cross-cut by a low-angle unconformity at the contact with younger units. Current models for the Neoproterozoic evolution of northwestern Canada emphasize Tonian deposition in an epicratonic basin, followed by Cryogenian to Ediacaran extension, or possibly transtension and extension. Recognition that this general extensional history was disrupted by a regional-scale contractional event significantly modifies our understanding of the tectonic history and stratigraphic evolution of the region.
Résumé(Résumé en langage clair et simple, non publié)
Ce résumé décrit un événement de déformation survenu au Néoprotérozoïque (il y a de 1000 à 450 millions d'années) qui a modifié le substratum rocheux des monts Mackenzie, de la plaine du Mackenzie et des monts Franklin dans les Territoires du Nord-Ouest.
GEOSCAN ID306155