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TitleChapter 7: Geology and tectonic evolution of the Slave Province - A post Lithoprobe Perspective
 
AuthorHelmstaedt, H; Pehrsson, S J
SourceTectonic Styles in Canada: The Lithoprobe Perspective ; by Percival, J A (ed.); Cook, F A (ed.); Clowes, R M (ed.); Geological Association of Canada, Special Paper no. 49, 2012 p. 379-466
LinksOnline - En ligne
Image
Year2012
Alt SeriesEarth Sciences Sector, Contribution Series 20100218
PublisherGeological Association of Canada
Documentserial
Lang.English
Mediapaper; on-line; digital
File formatpdf
ProvinceNorthern offshore region; Nunavut
NTS65; 75; 85; 66; 76; 86
AreaGreat Slave Province
Lat/Long WENS-120.0000 -96.0000 68.0000 60.0000
Subjectsgeophysics; general geology; geochronology; structural geology; accretion; isotopic studies; seismic data; Contwoyto terrane; Central Slave superterrane
Illustrationslocation maps; geological time charts; magnetic maps; geological sketch maps; stratigraphic columns; seismic reflection profiles; diagrams; plots
ProgramTargeted Geoscience Initiative (TGI-3), 2005-2010 Flin Flon TGI-3
AbstractA review of the surface geological record, subsurface geophysical data, and information from kimberlitic lower crustal and upper mantle samples suggests that the Slave Province has an Archean history consistent with a modified version of an accretionary model, originally proposed in the late 1980s, viewing the province as a tectonic collage of an Early Archean microcontinental nucleus and several Neoarchean juvenile terranes. The composite nucleus, referred to as Central Slave superterrane (CSST), is a fragment of a larger protocraton that evolved between ca. 4.0 and 2.85 Ga and rifted apart at the end of the Mesoarchean. Isotopic data indicate that Early Archean crust of the CSST was coupled with a depleted diamond-bearing lithospheric root prior to late Mesoarchean rifting and neoarchean terrane accretion. Remnants of Early Archean subcontinental lithospheric mantle (SCLM) survived metasomatism and tectonic erosion related to the rifting and terrane accretion, as well as a complex history of post-accretion late Neoarchean tectonism, metamorphism, and plutonism. They are best preserved below a north-northwest-trending corridor of the central Slave Province,
where the eastern part of the CSST is tectonically buried beneath the adjacent Contwoyto terrane. Eastwarddirected tectonic underplating of the Slave Province by Paleoproterozoic lithosphere, which is not obvious from the surface geology but was inferred from LITHOPROBE seismic and magnetotelluric evidence, was corroborated by Paleoproterozoic ages of eclogite xenoliths with subduction signatures and E-type diamonds from the Jericho and Diavik kimberlites. The Slave Province resembles other diamondiferous Archean cratons
in having yielded Early Archean P-type and Paleoproterozoic E-type diamonds, but it is the only known Archean craton for which Paleoproterozoic upper mantle samples can be linked with some certainty to Paleoproterozoic subduction along the craton margin.
GEOSCAN ID286326

 
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