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TitleU-Pb geochronology of the Neoarchean Swayze sector of the southern Abitibi greenstone belt
Authorvan Breemen, O; Heather, K B; Ayer, J A
SourceGeological Survey of Canada, Current Research (Online) no. 2006-F1, 2006, 32 pages; 1 CD-ROM,
PublisherNatural Resources Canada
Mediaon-line; CD-ROM; digital
File formatpdf (Adobe Acrobat Reader)
NTS41O/07; 41O/08; 41O/09; 41O/10; 41O/15; 41O/16; 41P/05; 41P/12; 41P/13; 42A/04; 42A/05; 42B/01; 42B/02; 42B/08
AreaCochrane; Sultan; Gogama; Ramsay; Biscotasing
Lat/Long WENS-83.0000 -81.5000 48.3833 47.2500
Subjectsgeochronology; stratigraphy; structural geology; regional geology; Archean; greenstone belts; radiometric dating; uranium lead dating; lead lead dates; zircon dates; titanite; geological history; tectonic history; tectonic elements; volcanism; intrusions; plutons; batholiths; stocks; dykes; sills; deformation; erosion; depositional history; provenance; source rocks; stratigraphic correlations; bedrock geology; lithology; igneous rocks; volcanic rocks; plutonic rocks; sedimentary rocks; metamorphic rocks; iron formations; greywackes; detritus; sandstones; conglomerates; clastics; granitic rocks; greenschists; amphibolites; rhyolites; komatiites; granites; monzonites; granodiorites; tonalites; trondhjemites; diorites; basalts; pillow lavas; pyroclastics; volcaniclastics; porphyries; tuffs; breccias; structural features; faults; faults, thrust; folds; synforms; antiforms; shear zones; Swayze Greenstone Belt; Abitibi Greenstone Belt; Superior Province; Kapuskasing Structural Zone; Porcupine-Destor Deformation Zone; Kenogamissi Granitoid Complex; Nat River Granitoid Complex; Ramsay-Algoma Granitoid Complex; Ridout Deformation Zone; Timiskaming assemblage; Porcupine assemblage; Upper Black River assemblage; Lower Black River assemblage; Tisdale assemblage; Kidd-Munro assemblage; Soughton-Roquemaure assemblage; Deloro assemblage; Pacaud assemblage; Larder Lake-Cadillac Deformation Zone; Wakami shear zone; Hanharan Antiform; Brett Lake Synform; Woman River Antiform; Ridout Synform; Ridout Group; North Arm Formation; Opeepeesway Formation; Swayze Group; Denyes Formation; Brett Lake Formation; Newton Formation; Trailbreaker Group; Heenan Formation; October Lake Formation; Marion Group; Woman River Formation; Strata Lake Formation; Bush River Formation; Chester Group; Yeo Formation; Arbutus Formation; Biscotasing Group; titanite dates; banded iron formations; supracrustal rocks; thermal ionization mass spectrometry analysis; Precambrian
Illustrationssketch maps; schematic sections; tables; Concordia diagrams; Box-and-whisker diagrams
ProgramTargeted Geoscience Initiative (TGI-3), 2005-2010
Released2006 12 01
AbstractPrecise U-Pb zircon geochronology of the Swayze greenstone belt reveals a 45 Ma history of volcanism with 19 ages ranging from 2739 Ma to 2695 Ma. Seven U-Pb ages demonstrate the coeval nature of regionally extensive 2.73 Ga iron-formation, which serves as a key stratigraphic marker correlative across major deformation zones. Age correlations are consistent with an upward-younging stratigraphic
succession without major tectonic breaks or disruption, which can be correlated with equivalent stratigraphy across the southern Abitibi greenstone belt. The youngest volcanic rocks are interlayered with greywackes for which detrital zircons from two samples establish maximum ages of deposition of 2683 ± 6 Maand 2695 ± 1 Ma. As the detrital zircon ages are mostly younger than 2704 Ma, the provenance
of these sediments is inferred to be exclusively volcanic rocks of the immediately lower pile. Detrital zircons from the youngest sedimentary rocks, sandstone of the unconformable and fault-bounded Ridout Group, provide a maximum depositional age limit of 2688 ± 2 Ma. Older detrital zircon ages, in the 2742 to 2735 Marange, are consistent with deeper erosional excavation of source rocks and more active tectonics at the time of deposition. The oldest plutonic rocks of 2.74 Ga are coeval with the oldest volcanic rocks recorded and no geochronological evidence for pre-existing basement has been found. Plutonism continued after cessation of extensive volcanism, including 2686 Ma to 2680 Ma syntectonic (D2) granitoids and post-tectonic granitoids as young at 2.66 Ga. Titanite ages of 2615 ± 3Ma to 2540 ± 4Ma are interpreted in terms of crystal growth from late-stage fluids.