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TitleU-Pb zircon age and regional setting of the Lapeyrère gabbronorite, Portneuf-Mauricie region, south-central Grenville Province, Quebec; Radiogenic age and isotopic studies: Report 14
AuthorNadeau, L; van Breemen, O
SourceGeological Survey of Canada, Current Research (Online) no. 2001-F6, 2001, 13 pages, (Open Access)
LinksGSC Geochronology Laboratory home page
PublisherNatural Resources Canada
Mediapaper; on-line; digital; CD-ROM
RelatedThis publication is contained in Stern, R A; (2001). Radiogenic age and isotopic studies: Report 14, Geological Survey of Canada, Current Research (Online) no. 2001-F
RelatedThis publication is contained in Geological Survey of Canada; Geological Survey of Canada; (2001). Current Research 2001, winter release, Geological Survey of Canada, Current Research no. 2001
File formatpdf
NTS31I/09; 31I/10; 31I/15; 31I/16; 31P/01; 31P/02; 31P/07; 31P/08; 31P/09; 31P/10; 31P/15; 31P/16
AreaLaTuque; Shawinigan; Montauban; Portneuf; Mauricie
Lat/Long WENS-73.0000 -72.0000 47.8333 46.5000
Subjectsgeochronology; radiometric dates; analytical methods; radiometric dating; zircon; Archean; uranium lead dates; gabbros; mafic intrusive rocks; anorthosites; Lapeyrère gabbronorite; gabbronorites; Proterozoic; Precambrian
Illustrationssketch maps; photomicrographs; graphs; tables
Released2001 07 01
AbstractHigh-grade tectonite bodies of the Portneuf Mauricie region were intruded by a number of small and scattered, late Grenvillian, mid-crustal gabbroic intrusions. These consist chiefly of fresh and massive gabbro and gabbronorite with well preserved igneous mineral textures, to locally recrystallized and foliated gneissic equivalents. The Lapeyrère gabbronorite is the largest of these intrusions. Uranium-lead dating of igneous zircon crystals gives a crystallization age at 1069 ± 2 Ma, close to ages previously reported for the Shawinigan gabbronorite, and two small gabbroic intrusions in Canton Taché, along the southern margin of the Lac-Saint-Jean anorthosite complex. Although modest in size, these distant intrusions signal a regionally extensive gabbroic intrusive event in the 1080 1067 Ma interval, at the onset of widespread granitoid plutonism in the south-central Grenville Province. The almost complete absence of anorthosite and the limited volume of gabbroic rocks, appear, however, to set apart this 1080 1067 Ma gabbroic pulse from those leading to classic anorthosite-mangerite-charnockite-granite (AMCG) association.