Mesozoic-Cenozoic paleomagnetism of the Intermontane and Yukon-Tanana terranes, Canadian Cordillera
Lithoprobe Slave  Northern Cordillera Lithospheric Evolution (SNORCLE) transect support enabled 24 paleomagnetic collections (536 sites, 6547 specimens) to be made in the northern Cordillera. Paleopoles from 16 studies are integrated with other published paleopoles to present a tectonic synthesis for the Intermontane Belt (IMB) and YukonTanana (YT) terranes since 215 Ma. It shows that the YT terrane has been parautochthonous with the North American craton at least since the Early Jurassic. Since 54 Ma the IMB terranes have rotated steadily clockwise at 0.29° ± 0.11°/Ma on top of the YT terrane and craton or by 16° ± 6° clockwise. Between 102 ± 14 and 54 Ma, the IMB terranes rotated another 35° ± 14° clockwise, probably during Paleocene collision with the craton, and were translated 8.3° ± 7.0° (2σ) (915 ± 775 km) northward, probably during the Late Cretaceous on the Kula plate. The 915 km estimate is much less than most paleomagnetic estimates for "Baja BC" but agrees with the geological evidence. These...