| Titre | 'Date to rate': mining the sedimentary record to study tectonic rates and timescales |
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| Auteur | Kellett, D A |
| Source | European Geophysical Union General Assembly 2019; Geophysical Research Abstracts vol. 21, EGU2019-10315, 2019 p. 1  Accès ouvert |
| Liens | Online - En ligne
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| Image |  |
| Année | 2019 |
| Séries alt. | Ressources naturelles Canada, Contribution externe 20190400 |
| Éditeur | European Geophysical Union |
| Réunion | European Geophysical Union General Assembly 2019; Vienna; AT; avril 7-12, 2019 |
| Document | publication en série |
| 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; Florence Range |
| Lat/Long OENS | -139.5000 -130.0000 65.0000 58.5000 |
| Sujets | Jurassique inférieur; bassins sédimentaires; évolution tectonique; orogenèse; accretion; érosion; terrains; métamorphisme; antecedents de sedimentation; historique de l'enfouissement; datation
radiométrique; datation au uranium-plomb; datations au zircon; minéraux détritiques; clastes; éclogîtes; muscovite; antecedents thermiques; Cordillère canadienne; Ceinture d'Intermontane ; Méthodologie; tectonique; sédimentologie; géochronologie;
Sciences et technologie; Nature et environnement; Phanérozoïque; Mésozoïque; 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 | 2019 04 01 |
| Résumé | (disponible en anglais seulement)
The geochronological community now has access to a wide range of methods, minerals and decay systems with which to study the tectonic evolution of orogens,
particularly dates and rates of metamorphism and deformation. While the preferred dating targets involve direct investigation of metamorphosed and deformed rocks using petrochronological approaches, much of the rock record of orogenesis has generally
eroded away, even in active orogens. Their erosional remnants preserved in syn-tectonic sedimentary basins thus provide a highly complementary record of the tectonic evolution of orogenesis. Sedimentary basins are commonly mined for their detrital
mineral age populations (e.g. zircon U-Pb), and coupled isotopic analyses (e.g. Hf) allow for increasingly detailed source characterization. However, this is just the tip of the iceberg for information that can be extracted from syn-tectonic basins.
In this case study, a range of approaches including detrital clast petrochronology, detrital multi-mineral thermochronology, and geo- and thermochronological double dating are applied to rocks from a syn-tectonic basin to interrogate the complex
history of accretion in an accretionary orogen setting.
The Intermontane suite of continental, island arc and oceanic terranes accreted to the western margin of North America in Early Jurassic, initiating the Canadian Cordillera. The Whitehorse
trough syn-tectonic basin preserves the erosional record of accretion of these terranes, including igneous, sedimentary and metamorphic sources. Petrochronology of mm-sized eclogite clasts reveals that peak high temperature metamorphism, rapid
cooling and exhumation, and deposited into the basin all occurred during Early Jurassic. Detrital muscovite ages indicate exhumation of other metamorphic source rocks during E. Jurassic. U-Pb - U-Th/He double dating of detrital zircon confirms
collapse of nascent volcanic rocks into the basin during the same period. Low temperature thermochronometers record post-E. Jurassic burial and shortening of the Whitehorse trough during ongoing collision. This comprehensive and diverse set of date
to rate data allows for new hypotheses on the tectonic setting of accretion in the Canadian Cordillera during the Early Jurassic. |
| GEOSCAN ID | 321675 |
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