Bibliographische Detailangaben
|
Personen und Körperschaften:
|
Kent, D V (VerfasserIn); Kjarsgaard, B A (VerfasserIn); Gee, J S (VerfasserIn); Muttoni, G (VerfasserIn); Heaman, L M (VerfasserIn) |
| Format: |
Elektronische Zeitschrift
|
| Sprache: |
English
|
| veröffentlicht: |
Wiley-Blackwell, 2015 |
| Gesamtaufnahme: |
GEM: Geo-mapping for Energy and Minerals
, Geochemistry, Geophysics, Geosystems (G3)
|
| Schlagwörter: |
Polar Wandering;
Uranium Lead Dates;
Uranium Lead Dating;
Kimberlites;
Paleomagnetic Poles;
Paleomagnetism;
Paleomagnetic Interpretations;
Superior Province;
Ontario;
Manitoba;
Northwest Territories;
Nunavut;
Northern Offshore Region;
Arctic;
Zeitschrift;
|
| Quelle: |
GEOSCAN
|
| Zusammenfassung: |
Different versions of a composite apparent polar wander (APW) path of varia...
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.
|
