| Title | Archean and Paleoproterozoic fault history of the Big Lake shear zone, MacQuoid-Gibson lakes area, Nunavut |
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| Licence | Please note the adoption of the Open Government Licence - Canada
supersedes any previous licences. |
| Author | Ryan, J J; Hanmer, S; Sandeman, H A; Tella, S |
| Source | Geological Survey of Canada, Current Research (Online) no. 2000-C6, 2000, 11 pages, https://doi.org/10.4095/211153  Open Access |
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| Year | 2000 |
| Publisher | Natural Resources Canada |
| Document | serial |
| Lang. | English |
| Media | on-line; digital; CD-ROM |
| Related | This publication is contained in Current Research 2000
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| File format | pdf |
| Province | Nunavut |
| NTS | 55M/09; 55M/16; 55N/11; 55N/12; 55N/13; 55N/14 |
| Area | Big Lake; MacQuoid Lake; Gibson Lake; Squiggly Lake; Chesterfield Inlet; Cross Bay |
| Lat/Long WENS | -94.5000 -93.0000 64.0000 63.5000 |
| Subjects | structural geology; igneous and metamorphic petrology; Archean; faults; shear zones; structural features; structural interpretations; metamorphic facies; mylonites; lithology; metamorphic rocks; dykes;
igneous rocks; gneisses; amphibolite facies; granulite facies; anorthosites; deformation; total field magnetics; Big lake shear zone; Precambrian; Proterozoic |
| Illustrations | sketch maps; stereograms; photographs |
| Program | Western Churchill NATMAP Project |
| Released | 2000 01 01 |
| Abstract | The Big lake shear zone in the MacQuoid Gibson lakes area comprises diverse mylonitic rocks with a complex tectonothermal history. The shear zone has an exposed strike length of 50 km, with abrupt
termination to the west. Central and eastern segments of the shear zone consist of dextral, amphibolite-facies, porphyroclastic mylonite and annealed straight gneiss. The western segment, however, is cored by variably retrogressed granulite-facies
mafic and anorthositic ultramylonite, within amphibolite-facies wall rocks, and has a more complex kinematic history. The granulite-facies rocks are spatially associated with the anorthosite sheets, which are interpreted here as the dominant heat
source of the localized high-grade event. The ultramylonite units are crosscut by undeformed ca. 2.19 Ga MacQuoid dykes, constraining the high-grade, high-strain event to be older. Regional aeromagnetic data illustrate that the western segment is
truncated by two faults of (?)Proterozoic age.
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| GEOSCAN ID | 211153 |
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