| Title | Recent advances in our understanding of the Brock Inlier, Northwest Territories |
| |
| Author | Rainbird, R H ;
Craven, J A; Rayner, N; Turner, E C; Ielpi, A; Bouchard, M;
Javaux, E; Jackson, V A; Fischer, B J; Greenman, J W; Gibson, T |
| Source | Margins through time: GAC-MAC 2016; Geological Association of Canada-Mineralogical Association of Canada, Joint Annual Meeting, Programs with Abstracts vol. 39, 2016 p. 75  Open Access |
| Links | Online - En ligne (complete volume - volume
complet, PDF, 1.3 MB)
|
| Year | 2016 |
| Alt Series | Natural Resources Canada, Contribution Series 20190419 |
| Publisher | Geological Association of Canada |
| Meeting | GAC-MAC 2016; Whitehorse, YK; CA; June 1-3, 2016 |
| Document | serial |
| Lang. | English |
| Media | on-line; digital |
| File format | pdf |
| Province | Northwest Territories |
| Area | Darnley Bay |
| Subjects | stratigraphy; paleontology; geochronology; Science and Technology; Nature and Environment; Brock Inlier |
| Program | GEM2: Geo-mapping for Energy and Minerals Mackenzie Corridor, Shield to Selwyn |
| Released | 2016 06 01 |
| Abstract | Our studies of Brock Inlier comprise an activity within the GSC's GEM2 Mackenzie Shield to Selwyn geo-transect: studying the evolution of sedimentary rocks of the northern mainland NWT to improve
exploration success. The Brock Inlier, an uplifted region of mostly early Neoproterozoic sedimentary rocks surrounded by lower Paleozoic and Cretaceous sedimentary rocks, is located just east of Darnley Bay, Northwest Territories. It overlies the
eastern edge of the Darnley Bay anomaly, the largest gravity and magnetic anomaly measured in North America. Preliminary responses from 17 magneto-telluric survey stations along an E-W profile over the anomaly indicate that the overall thickness of
the sedimentary succession above it is considerably greater along the western portion of the profile and suggest a conductive feature in the vicinity of the known anomaly. Our stratigraphic work has documented the first complete detailed record of
the early Neoproterozoic Shaler Supergroup and Cambrian-Ordovician Mt Clark, Mt. Cap and Franklin Mountain formations; sandstone, shale and carbonate rocks exposed along the Hornaday River. Samples of these rocks have been collected for
paleontological, geochronological and geochemical analysis. Preliminary analysis of shales from the Shaler Supergroup reveals a microfossil assemblage characteristic of other late Mesoproterozoic-early Neoproterozoic successions including:
unambiguous eukaryotes (process-bearing acritarchs) Trachyhystrichosphaera aimika (~1.1 - 0.75 Ga) and Dictyosphaera sp. (~1.6 - 0.8 Ga; first reported occurrence in Canada). Stable C-O isotope values from the Mikkelsen Islands Formation offer
stratigraphic variations that are consistent with possibly correlative carbonate-bearing successions in the northern Cordillera, > 500 km to the southwest. Samples of fluvial quartz arenite collected from the base and top of the Nelson Head Formation
have almost identical detrital zircon U-Pb concordia age profiles with overwhelmingly Mesoproterozoic age sources, interpreted to have been mainly from the Grenville Province of eastern Laurentia. Helicopter-supported regional geological
reconnaissance and selected ground traverses in key areas of NTS 97A (Erly Lake) and 97D (Brock River) are allowing us to build new and improved geological maps. This work is being aided by processing and analysis of newly acquired, high resolution
remotely sensed and video imagery. |
| GEOSCAN ID | 321694 |
|
|