Tectonostratigraphic syntheses of Proterozoic rocks worldwide have allowed plausible reconstructions for Rodinia, the early Neoproterozoic supercontinent, and its predecessor Nuna, assembled by 1.8 Ga. Many different reconstructions have been postulated, however, that have yet to be tested with high-quality paleomagnetic data. Tectonostratigraphic similarities between Archean-Proterozoic terrains in Laurentia (cratonic North America) and Australia form the bases for most modern conceptions of Rodinia; if valid, these comparisons would also pertain to Nuna configurations. One recent high-quality paleomagnetic study has cast doubt upon the most popular earlier juxtapositions of Proterozoic Laurentia and Australia, known as SWEAT and AUSWUS; that study identified a third possible reconstruction, dubbed AUSMEX. The PI seeks to test these hypothesized juxtapositions further, by collecting new paleomagnetic and geochronological data from well preserved 1.8-1.6 Ga volcanic- sedimentary successions in central Canada and northern Australia. These results will generate refined apparent-polar-wander paths for the two cratons during that interval and thus permit quantitative tests for Nuna and Rodinia reconstructions. Broader scientific impacts of the proposed research follow the recognition that accurate continental reconstructions form paleogeographic foundations for all aspects of Earth surface processes, and they provide boundary conditions for models of mantle geodynamics. Broader impacts also include research training for graduate and undergraduate students, including a female graduate student aspiring toward a career in academia.
