| Title | Recent advances in the geology and structure of the Confederation Lake region, northwestern Ontario |
| Download | Download (whole publication) |
| Author | Rogers, N; van staal, C R; McNicoll, V |
| Source | Canadian Shield/Bouclier canadien; by Geological Survey of Canada; Geological Survey of Canada, Current Research no. 1999-C, 1999 p. 187-195, https://doi.org/10.4095/210184 |
| Year | 1999 |
| Publisher | Natural Resources Canada |
| Document | serial |
| Lang. | English |
| Media | paper |
| Related | This publication is contained in Geological Survey of
Canada; Geological Survey of Canada; (1999). Canadian Shield, Geological Survey of Canada, Current Research no. 1999-C |
| Province | Ontario |
| NTS | 52N/02 |
| Area | Confederation Lake; Bear Lake; Narrow Lake; Perrigo Lake; Woman Lake |
| Lat/Long WENS | -93.0000 -92.5000 51.2500 51.0000 |
| Subjects | structural geology; geochronology; igneous and metamorphic petrology; deformation; metamorphism; shear zones; structural features; uranium lead dates; radiometric dates; lithology; volcanic rocks;
basalts; gabbros; diabases; dykes; sills; igneous rocks; zircon dates; plutonic rocks; granodiorites; quartz diorites; lineations; rhyolites; sandstones; sedimentary rocks; field relations; structural interpretations; Archean; Rowe Lake shear zone;
Uchi Subprovince; Uchi-Confederation greenstone belt; Balmer assemblage; Woman assemblage; Confederation assemblage; Precambrian |
| Illustrations | sketch maps; photographs; cross-sections |
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| Program | Western Superior NATMAP Project |
| Released | 1999 02 01 |
| Abstract | The Uchi-Confederation greenstone belt consists of three distinct lithotectonic assemblages (Balmer, Woman, and Confederation) spanning at least 240 million years (2975- 2735 Ma). At least two phases of
deformation have affected the entire stratigraphic sequence. None of the assemblage boundaries are marked by high-strain zones, and no evidence for accretionary structures has been identified. Where assemblage boundaries are tectonic, the shear zones
are narrow, sinistral, late syn- to post-D2 structures with relatively minor motion. Uranium-lead dates of 2832 Ma for gabbro dykes demonstrate that the Woman assemblage was fed through the Balmer assemblage (2975 Ma). Hence, the Balmer-Woman
assemblage boundary is a disconformity. The Woman-Confederation assemblage boundary partially occurs along the Rowe Lake shear zone. However, field evidence suggests that the original boundary is a disconformity marked by a sedimentary rock package.
These relationships suggest that the assemblage concept needs critical reassessment within the Uchi Subprovince. |
| GEOSCAN ID | 210184 |
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