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TitreNew geochronological constraints on Jurassic deformation of the western edge of North America, southeastern Canadian Cordillera
AuteurMurphy, D C; van der Heyden, P; Parrish, R R; Klepacki, D W; McMillan, W; Struik, L C; Gabites, J
SourceJurassic magmatism and tectonics of the North American Cordillera; par Miller, D M (éd.); Busby, C (éd.); Geological Society of America, Special Paper 299, 1995 p. 159-171,
Séries alt.Commission géologique du Canada, Contributions aux publications extérieures 52091
ÉditeurGeological Society of America
Documentpublication en série
Mediapapier; en ligne; numérique
SNRC82L; 92P; 92I; 92O; 93A; 93B; 82M
Lat/Long OENS-122.0000 -118.0000 53.0000 49.0000
Sujetsdatations au uranium-plomb; datations au zircon; stratigraphie paléontologique; bassins sédimentaires; terrains; géochronométrie; déformation; marges continentales; Toarcien; plissement; Ceinture d'Omineca ; Terrane de Kootenay ; Complexe de Monashee ; géochronologie; géologie générale; géologie structurale; Mésozoïque
Illustrationslocation maps; geological sketch maps; schematic cross-sections; tables; Concordia diagrams
ProgrammeCRSNG Conseil de recherches en sciences naturelles et en génie du Canada
ProgrammeBritish Columbia Ministry of Energy, Mines and Petroleum Resources, Geological Survey Branch, Funding Program
Diffusé1995 01 01
Résumé(disponible en anglais seulement)
This report presents four U/Pb zircon dates from the Kootenay arc and Cariboo Mountains of southeastern British Columbia. When combined with existing biochronological data, two of these dates tightly constrain the age of shortening of the sedimentary basin between the North American continental margin and the Triassic-Jurassic Quesnellia volcanic arc to mid-Toarcian (late Early Jurassic, ca. 187 - 185 Ma). The other two dates affirm a Mesozoic age of the prominent phase of southwest-vergent folding in the Omineca crystalline belt and permit correlation of these structures with similar folds of the mid-Toarcian Quesnellia - North America terrane boundary. Previously published dates and geological relationships show that this latter southwest-vergent folding was finished by the end of the Aalenian (earliest Middle Jurassic, 174 Ma). Taken together, these data show that the earliest two "phases" of Jurassic deformation of the western edge of North America occurred in a ca. 10-million year interval spanning the Early to Middle Jurassic boundary. Although this deformation consists of two phases, given the short time interval, it is likely that they are part of the same continuous episode of shortening of the continental margin.