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TitleNeoproterozoic deformation in eastern Mackenzie Mountains and Mackenzie Plain, Northwest Territories
AuthorFallas, K M; MacLean, B C; MacNaughton, R B
Source 2017 p. 25-26
LinksOnline - En ligne (1.7 MB)
Alt SeriesNatural Resources Canada, Contribution Series 20170253
PublisherNorthwest Territories Geological Survey
MeetingYellowknife Geoscience Forum; Yellowknife; CA; November 14-16, 2017
Mediapaper; on-line; digital
File formatpdf
ProvinceNorthwest Territories
AreaMackenzie Mountains; Mackenzie Plains
Subjectsstratigraphy; regional geology; deposition; seismic interpretations; seismic reflection surveys; seismic surveys, ground; folding; bedrock geology; unconformities; stratigraphic models; Mackenzie Mountains Supergroup; Coates Lake Group
ProgramMackenzie Corridor, Shield-to-Selwyn geo-transect, Mackenzie-Selwyn sub-activity, GEM2: Geo-mapping for Energy and Minerals
AbstractBedrock 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.
Summary(Plain Language Summary, not published)
This abstract describes a Neoproterozoic (1000-540 million years ago) deformation event affecting bedrock in the Mackenzie Mountains, Mackenzie Plain, and Franklin Mountains of the Northwest Territories.