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Title40Ar/39Ar hornblende and biotite cooling ages for metaplutonic rocks of the central Thelon Tectonic Zone, Nunavut
LicencePlease note the adoption of the Open Government Licence - Canada supersedes any previous licences.
AuthorCamacho, A; Berman, R GORCID logo; Sanborn-Barrie, MORCID logo
SourceGeological Survey of Canada, Open File 8625, 2020, 77 pages, Open Access logo Open Access
PublisherNatural Resources Canada
Documentopen file
Mediaon-line; digital
File formatreadme
File formatpdf (Adobe® Reader®); rtf; xlsx (Microsoft® Excel®)
NTS76H; 76I
AreaDuggan Lake; Overby Lake; Queen Maud Migratory Bird Sanctuary; Ellice River; Thelon Wildlife Sanctuary; Back River
Lat/Long WENS-106.0000 -104.0000 67.0000 65.0000
Subjectsregional geology; geochronology; tectonics; Science and Technology; radiometric dating; argon argon dating; mass spectrometer analysis; thermal history; tectonic evolution; metamorphism; models; hornblende; biotite; bedrock geology; basement geology; lithology; metamorphic rocks; granodiorites; monzonites; monzo-granites; diorites; monzodiorites; gabbros; tonalites; Archean; Canadian Shield; Thelon Tectonic Zone; Rae Craton; Queen Maud block; Slave Craton; Overby Lake Domain; Ellice River Domain; Duggan Lake Domain; Bathurst Fault; Yellowknife Supergroup; Precambrian; Proterozoic
Illustrationslocation maps; geoscientific sketch maps; bar graphs
ProgramGEM2: Geo-mapping for Energy and Minerals Rae Province, Chantrey-Thelon
Released2020 01 06
Summary(Plain Language Summary, not published)
Forty-three 40Ar/39Ar cooling ages of single crystals of hornblende and biotite were obtained from metaplutonic rock samples across the central Thelon tectonic zone (Ttz), adjacent eastern Slave craton, and western Rae craton. The oldest hornblende (2.49 Ga) and biotite (1.98 Ga) ages occur in the Slave craton; this biotite age coincides with the time of widespread Ttz plutonism, somewhat earlier than the 1.97 Ga time of the Slave-Rae collision previously proposed. Widespread ca. 1.89-1.87 Ga hornblende ages across much of the central Ttz and western Rae craton reflect cooling through ~550°C at this time. The southern regions of the Western and Central plutonic belts record younger hornblende ages (ca. 1.83-1.80 Ga) indicating this region remained at a deeper crustal level and cooled through ~550°C some 40-65 million years later. These cooling age contrasts reflect diachronous exhumation which appears to be influenced by NW-trending structures parallel to the Bathurst fault.

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