The exotic crustal province termed Mojavia indicates that there was something attached to the western margin of North America during the Precambrian. Further evidence is provided by missing sedimentary sources of Proterozoic and Paleozoic sedimentary basins, as well as multiple rifting stages in the Precambrian and Paleozoic formations. The supercontinent of Rodinia was proposed to exist during the Precambrian, leading to many different models for the configuration. SWEAT (Southwestern US and East Antarctica) and AUSWUS (Australia and western US) are the most popular and have the most supporting evidence. Other models proposed include Tasmania-Nevada, South China-western US, and Siberia-western US. This website evaluated the data from Mojavia and the Proterozoic-Paleozoic formations supporting these models. The SWEAT model connects Mojavia with the Miller Range in Antarctica, and the Pahrump group with the Patuxent formation in Antarctica. AUSWUS connects Mojavia with the Broken Hill block in Australia and the Belt basin with the Gawler craton of Australia. The AUSWUS model has been argued to be the better fit, from statistical methods (Burrett and Berry, 2001; Karlstrom et al., 2001). The other models proposed do not have enough evidence to support their configurations. While the other models do have supporting evidence for one aspect of the geology that results from their configurations, they are not able to fit all the resulting geological aspects well. The paleomagnetic data supporting any of the models is extremely sparce and can be unreliable (Meert and Powell, 2001). The difficulty in using Nd crustal model ages to determine the best fit model is obviously that too many terranes can be fit together. No two terrains can be conclusively fit together, or there would be no dispute over which model was correct. Because the configuration of Rodinia is very important for studies of the Precambrian (beginning of life, snowball earth, etc.) this topic will hopefully someday be resolved. More studies in Antarctica and Australia have been proposed by each model. Clearly more data is need before this debate can be resolved. One thing is clear, the best model needs to be able to both fit Mojavia with an Archaen source and the Paleozoic sedimentary basins with the appropriate sediment source as well as the other geology resulting from the configurations.
***coming soon: survey form to vote on which model you support!