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TitleGeology of the Striding-Athabasca mylonite zone, northern Saskatchewan and southeastern District of Mackenzie, Northwest Territories
LicencePlease note the adoption of the Open Government Licence - Canada supersedes any previous licences.
AuthorHanmer, S
SourceGeological Survey of Canada, Bulletin 501, 1997, 92 pages, Open Access logo Open Access
PublisherNatural Resources Canada
Mediapaper; on-line; digital
File formatpdf
ProvinceSaskatchewan; Northwest Territories
NTS65D/04; 65D/05; 65D/06; 65D/11; 65D/12; 65D/13; 65D/14; 65D/15; 65E/02; 65E/03; 65E/07; 74O/07; 74O/08; 74P/05; 74P/06; 74P/11; 74P/12
AreaStony Rapids; Selwyn Lake; Wholdaia Lake; Snowbird Lake
Lat/Long WENS-107.0000 -105.0000 59.7500 59.2500
Lat/Long WENS-104.2500 -103.0000 61.5000 60.0000
Subjectstectonics; igneous and metamorphic petrology; structural geology; Archean; mylonites; granulites; metamorphic rocks; subduction; tectonic interpretations; tectonic elements; tectonic environments; tectonic evolution; tectonic models; plutonic rocks; mafic rocks; tonalites; igneous rocks; alteration; lithology; granites; shear zones; structural interpretations; structural analyses; faults; structural features; deformation; metamorphism; field relations; mylonitization; neodymium samarium dates; radiometric dates; Striding Mylonite Belt; Striding-Athabasca Mylonite Zone; East Athabasca Mylonite Triangle; East Athabasca Mylonite Zone; Snowbird Tectonic Zone; Precambrian
Illustrationssketch maps; photographs; analyses
Released1997 09 01; 2014 03 25
AbstractStriding-Athabasca mylonite zone, northern Saskatchewan and southeastern District of Mackenzie, N.W.T., occupies a 400 km long segment of the Snowbird tectonic zone. It is a linked system of Archean granulite facies mylonite belts (East Athabasca mylonite triangle and Striding mylonite belt), which trace a sinuous course along a train of lozenges of stiff Middle Archean crust.
Middle Archean mafic and tonalitic rocks may represent part of a plutonic arc emplaced into a sedimentary accretionary wedge above a subduction zone during the early construction of the western Churchill continent, and affected by contemporaneous granulite facies mylonitization. By the Late Archean, ca. 2.62-2.60 Ga, this segment of the Snowbird tectonic zone, located well within the interior of the western Churchill continent, was invaded by voluminous mafic and granitic plutons, and subjected to further granulite facies mylonitization. Striding-Athabasca mylonite zone was not the site of an Early Proterozoic suture or orogen.
The geometry of the Archean/Early Proterozoic boundary in the western Canadian Shield may represent a jagged continental margin, composed of a pair of re-entrants defined by rifted and transform segments, inherited from Early Proterozoic break-up. Rifting may have been controlled by the Archean structure of the interior of the western Churchill continent, i.e., the Striding-Athabasca mylonite zone, with its associated Middle Archean lozenges, and Late Archean mylonites of the Great Slave Lake shear zone. The geometry of this jagged margin appears to have strongly influenced the Early Proterozoic tectonic evolution of the edge of the western Canadian Shield.

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