LONG-LIVED RODINIA, RADICALLY REVISED

Recent paleomagnetic data have stretched traditional Rodinia models to the point of imminent rupture. As examples, a direct Rodinian connection between western Laurentia and Australia can only be accommodated by the AUSMEX reconstruction with collision after 1200 Ma and breakup prior to 755 Ma, but such events are not well represented in the North American Cordillera. Incorporation of geomagnetic polarity from precisely dated igneous rocks in Laurentia and Kalahari refutes all published direct juxtapositions of those two cratons at 1110 Ma. High-latitude position of Congo-SF at 1080–1010 Ma appear to conflict with low-latitude positions of other cratons, suggesting that Congo-SF should be excluded from Rodinia altogether. Amazon may have collided with southern Laurentia at 1200 Ma, but it is recently depicted as "rolling" along the Grenville margin to a final resting place near Labrador at ca.1000 Ma, a rather improbable kinematic evolution. In summary, the recent paleomagnetic data would seem to require that Rodinia was rather small, short-lived, and internally mobile: possible, of course, but hardly worthy of the title, "supercontinent."

If Rodinia was instead long-lived and internally stable, then a unique reconstruction of its constituent cratons can be determined by erecting a master paleomagnetic apparent polar wander path for the entire supercontinental interval. I have assembled such a path that only violates one set of paleomagnetic results from poorly dated dykes in Brazil, which are currently under U-Pb reinvestigation. My proposed Rodinia includes some traditional connections, including Greenland-Baltica and Australia-India-South China similar to those presented in the published literature. The radical Rodinia revisions include: western Laurentia connected to elements of "West" Gondwanaland such as West Africa, Plata, and Amazon; northern Laurentia connected to Congo-SF, Australia connected to Baltica but not directly with Laurentia, Kalahari next to Mawsonland, and Siberia on the outer edge of the supercontinent beyond India. There are many intriguing possible intercratonic correlations that can be drawn in the framework of an entirely different global context, and I hope that the revised Rodinia inspires more attention on previously neglected cratons such as West Africa and Plata.