| Titre | Tracking the Late Jurassic apparent (or true) polar shift in U-Pb-dated kimberlites from cratonic North America (Superior Province of Canada) |
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| Auteur | Kent, D V; Kjarsgaard, B A ; Gee, J S; Muttoni, G; Heaman, L M |
| Source | Geochemistry, Geophysics, Geosystems (G3) vol. 16, issue 4, 2015 p. 983-994, https://doi.org/10.1002/2015GC005734  Accès ouvert |
| Image |  |
| Année | 2015 |
| Séries alt. | Secteur des sciences de la Terre, Contribution externe 20150057 |
| Éditeur | Wiley-Blackwell |
| Document | publication en série |
| Lang. | anglais |
| DOI | https://doi.org/10.1002/2015GC005734 |
| Media | papier; en ligne; numérique |
| Formats | pdf |
| Province | Ontario; Manitoba; Territoires du Nord-Ouest; Nunavut; Région extracotière du nord |
| SNRC | 41; 42; 43; 53; 54; 55; 56; 57; 58; 59; 63; 64; 65; 66; 67; 68; 69; 76; 77; 78; 79; 86; 87; 88; 89; 96; 97; 98; 99; 106; 107; 116; 117 |
| Région | Arctic |
| Lat/Long OENS | -152.0000 -88.0000 85.0000 35.0000 |
| Sujets | dérive du pôle; datations au uranium-plomb; datation au uranium-plomb; kimberlites; pôles paléomagnétiques; paléomagnétisme; interprétations paléomagnétiques; Province de Superior ; géochronologie;
Mésozoïque; Jurassique |
| Illustrations | cartes de localisation; graphiques |
| Programme | GEM : La géocartographie de l'énergie et des minéraux Diamands |
| Diffusé | 2015 04 02 |
| Résumé | (disponible en anglais seulement)
Different versions of a composite apparent polar wander (APW) path of variably selected global poles assembled and averaged in North American coordinates using
plate reconstructions show either a smooth progression or a large (~30°) gap in mean paleopoles in the Late Jurassic, between about 160 and 145 Ma. In an effort to further examine this issue, we sampled accessible outcrops/subcrops of kimberlites
associated with high-precision U-Pb perovskite ages in the Timiskaming area of Ontario, Canada. The 154.9?±?1.1 Ma Peddie kimberlite yields a stable normal polarity magnetization that is coaxial within less than 5° of the reverse polarity
magnetization of the 157.5?±?1.2 Ma Triple B kimberlite. The combined ~156 Ma Triple B and Peddie pole (75.5°N, 189.5°E, A95?=?2.8°) lies about midway between igneous poles from North America nearest in age (169 Ma Moat volcanics and the 146 Ma
Ithaca kimberlites), showing that the polar motion was at a relatively steady yet rapid (~1.5°/Myr) pace. A similar large rapid polar swing has been recognized in the Middle to Late Jurassic APW path for Adria-Africa and Iran-Eurasia, suggesting a
major mass redistribution. One possibility is that slab breakoff and subduction reversal along the western margin of the Americas triggered an episode of true polar wander. |
| Sommaire | (Résumé en langage clair et simple, non publié)
Détermination de l'âge et de données intégrée paléomagnétiques sont utilisés pour examiner les processus terre-échelle au cours teh période il
ya 160 à 145 Ma. |
| GEOSCAN ID | 296438 |
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