| Titre | Post-accretionary fault deformation of the Intermontane region, southern Yukon and northern British Columbia, Canadian Cordillera |
| |
| Auteur | Kellett, D A ;
Ryan, J J; Zagorevski, A; Colpron, M; Joyce, N |
| Source | Cordilleran Tectonic Workshop, 2018; 2018 p. 40  Accès
ouvert |
| Liens | Online - En ligne (PDF,
complete volume - volume complet, PDF, 4.80 MB)
|
| Image |  |
| Année | 2018 |
| Séries alt. | Ressources naturelles Canada, Contribution externe 20190220 |
| Réunion | Cordilleran Tectonic Workshop; Whitehorse, YT; CA; mars 2-4, 2018 |
| Document | livre |
| Lang. | anglais |
| Media | en ligne; numérique |
| Formats | pdf |
| Province | Yukon; Colombie-Britannique |
| SNRC | 104J; 104K; 104L; 104M; 104N; 104O; 105B; 105C; 105D; 105E; 105F; 105G; 105L; 115A; 115G; 115H; 115I; 115J |
| Région | Whitehorse; Atlin Lake; Dawson |
| Lat/Long OENS | -139.5000 -130.0000 65.0000 58.5000 |
| Sujets | antécédents tectoniques; formation de failles; déformation; historique de l'enfouissement; antecedents thermiques; volcanisme; géologie du substratum rocheux; géologie du socle; caractéristiques
structurales; failles; mouvements des plaques; analyse cinématiques; analyses thermiques; temperature; datation radiométrique; datation au uranium-plomb; datations au zircon; datations par traces de fission; datation argon-argon; datation au
potassium-argon; muscovite; établissement de modèles; modèles; illite; calcite; Paléogène; Ceinture d'Intermontane ; Cordillère canadienne; Faille de King Salmon ; Groupe de Laberge ; tectonique; géologie structurale; géochronologie; Sciences et
technologie; Nature et environnement; Phanérozoïque; Cénozoïque; Tertiaire; Mésozoïque; Crétacé; Jurassique |
| Programme | GEM2 : La géocartographie de l'énergie et des minéraux Évolution tectonique du Yukon, haut mésozoïque au tertiaire de l'ouest de la
Cordillère |
| Diffusé | 2018 03 01 |
| Résumé | (disponible en anglais seulement)
Jurassic and later post-accretionary structures in the northern Canadian Cordillera generally lack absolute timing constraints and their kinematics are only
broadly understood. This is largely due to the challenges in directly dating motion on brittle faults, as well as the recessive nature of brittle faults which often form linear topographic lows in the landscape. Low temperature multi-thermochronology
can provide constraints on timing and kinematics of brittle faults. Apatite and zircon U-Th/He and fission track dating methods are used to develop footwall and hanging wall temperature-time models for Jurassic to Paleogene faults in the Intermontane
region of southern Yukon and northern British Columbia.
Preliminary results, which also incorporate complementary detrital zircon U-Pb and detrital muscovite Ar/Ar age data, illustrate the potential of these methods for reconstructing the
post-accretionary structural history of the Intermontane region. For example, multi-geo- and thermochronological results across the King Salmon fault in northern British Columbia demonstrate contrasting burial/heating and cooling histories for
footwall and hanging wall Laberge Group units of the Whitehorse trough. Detrital zircon U-Pb data constrain comparable Pliensbachian to Toarcian depositional ages for Laberge Group samples from both structural positions and zircon double dating
results (U-Pb and U-Th/He ages from individual crystals) confirm their volcanic source. Muscovite in footwall Laberge Group rocks preserve undisturbed Early Jurassic detrital ages, while zircon U-Th/He yields reset Early Cretaceous ages. Thus
footwall Laberge Group and older basement rocks were buried and heated to between 400-180 °C during Late Jurassic (Oxfordian) to Early Cretaceous (Albian) while hanging wall Laberge Group rocks remained above ~180 °C. Both footwall and hanging wall
Laberge Group rocks exhibit cooling through ~40 °C at ca. 40 Ma suggesting a common late exhumation history. These temperature-time models will be compared where possible against age constraints obtained by direct dating of fault materials: K-Ar
dating of fault gouge illite and U-Pb dating of calcite slickenfibres. |
| GEOSCAN ID | 321385 |
|
|