Paleoproterozoic-Neoproterozoic North America Australia link: New evidence from paleomagnetism

Comparison of a new ∼1700 1600 Ma segment of the Proterozoic apparent polar wander path (APWP) for Australia with the time-equivalent segment of the North American APWP that has been rotated clockwise by 117° about the Euler pole, long 100°E, lat 38°N, superposes the North American APWP onto the Australian APWP and shows the segments to be similar. The same rotation makes the Pacific margins of the North American and Australian cratons adjacent, as predicted by the Southwest U.S. East Antarctic (SWEAT) hypothesis, but North America is located farther north relative to Australia than originally suggested. However, the reconstruction is consistent with the identification of western sediment sources for the Belt-Purcell basin in western North America, with matching of basement provinces, and with correlation of major lineaments of the two continents. The rotation gives only very broad agreement between the younger Proterozoic pole sets. This is probably partly due to the sparseness of poles on the Australian APWP whereby prominent features that are found on the North American APWP, such as the Grenville loop, are eliminated on the Australian path by smoothing. Nevertheless, some discrepancies between the younger Proterozoic poles cannot be accounted for without revision of the APWPs.