| Titre | Post-accretionary fault deformation of the Intermontane region, Yukon and northern British Columbia, Canada |
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| Auteur | Kellett, D A ;
Banjan, M; Coutand, I; Ryan, J J; Zagorevski, A; Colpron, M;
Joyce, N |
| Source | Thermo 2018: 16th International Conference on Thermochronology, conference abstracts; 2018 p. 105  Accès ouvert |
| Liens | Online - En ligne (PDF, complete volume -
volume complet, PDF, 9.72 MB)
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| Image |  |
| Année | 2018 |
| Séries alt. | Ressources naturelles Canada, Contribution externe 20190219 |
| Réunion | Thermo 2018 - 16th International Conference on Thermochronology; Quedlinburg; DE; Septembre 16-21, 2018 |
| Document | livre |
| Lang. | anglais |
| 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 09 01 |
| Résumé | (disponible en anglais seulement)
Jurassic to Paleogene 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 their recessive nature, which can make the primary fault surfaces difficult to access. Low temperature multi-thermochronology and direct
dating methods for fault-generated materials are well-suited to provide constraints on timing and kinematics of brittle faults, but have rarely been applied together.
Here we apply apatite and zircon (U-Th)/He and fission track dating 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 comparable depositional age. Detrital zircon U-Pb ages constrain depositional ages for Laberge Group samples
from both structural positions. Zircon double dating results (U-Pb and (U-Th)/He ages from individual crystals) confirm a volcanic source for the zircon. Muscovite in footwall Laberge Group rocks preserve undisturbed Early Jurassic detrital ages.
Thus footwall Laberge Group and older basement rocks were buried and heated to 400-170 °C during Late Jurassic (Oxfordian) to Early Cretaceous (Albian) while hanging wall Laberge Group rocks remained cooler than ~170 °C. Both footwall and hanging
wall Laberge Group rocks exhibit cooling through ~40 °C at ca. 40 Ma suggesting a common Tertiary exhumation history. Temperature-time models resulting from this yet-evolving dataset 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 | 321209 |
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