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TitreArchean zircons in Cretaceous strata of the western Canadian Cordillera: The "Baja B.C." hypothesis fails a "crucial test"
AuteurMahoney, J B; Mustard, P S; Haggart, J W; Friedman, R M; Fanning, C M; McNicoll, V J
SourceGeology vol. 27, no. 3, 1999 p. 195-198,<0195:AZICSO>2.3.CO;2
LiensAbstract - Résumé
Séries alt.Commission géologique du Canada, Contributions aux publications extérieures 1998079
ÉditeurGeological Society of America
Documentpublication en série
Mediapapier; en ligne; numérique
ProvinceColombie-Britannique; Région extracotière
SNRC92; 93; 94; 95; 102; 103; 104; 105; 106; 107; 114; 115; 116; 117
Lat/Long OENS-146.0000 -108.0000 70.0000 20.0000
Sujetsmarges continentales; paléomagnétisme; terrains; craton; zircon; Archéen; accretion; tectonique de plaques; roches plutoniques; bassins intramontagneux; tectonique; géologie structurale
Illustrationslocation maps; stratigraphic columns
ProgrammeCRSNG Conseil de recherches en sciences naturelles et en génie du Canada
Résumé(disponible en anglais seulement)
The magnitude of late Mesozoic terrane translation along the western North American continental margin is controversial. Paleomagnetic data suggest more than 3000 km of dextral displacement of the Insular superterrane and associated assemblages between ca. 74 and 50 Ma. Conversely, geologic evidence is more compatible with less than 500 km of offset during this time. Precambrian cratonic rocks older than 2.5 Ga are restricted to northern latitudes (above 40°N) in North America, and the presence or absence of Archean zircons within easterly derived Cretaceous strata has been proposed as a "crucial test" of the major translation hypothesis. There is no plausible source of Archean and Early Proterozoic zircons found in the Queen Charlotte, Nanaimo, and Methow basins other than the Canadian Shield or closely associated Proterozoic strata. The coexistence of Archean-Early Proterozoic, Middle Proterozoic (1.5-1.6 Ga) and Mississippian detrital zircon in these basins indicates deposition in northern latitudes, incompatible with the Baja B.C. hypothesis.