AEROMAGNETIC DATA GUIDE RECONSTRUCTIONS OF PARTS OF RODINIA

Numerous reconstructions of the Proterozoic supercontinent of Rodinia have been proposed, but there is little agreement on any firm piercing points between any two continental blocks between ages 1700 and 500 Ma. Reconstructions are also hampered by lack of reliable paleomagnetic poles for the late Proterozoic. Aeromagnetic data provide an additional method for the Precambrian tectonic reconstructions in that they tie together isolated interpretations of geologic information through continuous data coverage, provide plate-scale views of geology and tectonics and extend interpretations of units buried beneath cover. Recent release of continental-scale aeromagnetic compilations allows us to use them for plate-tectonic scale reconstructions as well as defining Precambrian crystalline basement terranes. Our approach is to identify key piercing points in existing plate reconstruction models for western Laurentia, eastern Australia, East Antarctica and northern Siberia, and where possible, determine the sources of magnetic anomalies in the region. We compare anomaly amplitude, wavelength and trend across continental boundaries. Of the tested reconstructions, the AUSWUS fit and the NE Siberia – SW Laurentia connection are not consistent with the aeromagnetic data. The SWEAT fit is still possible because of the lack of critical magnetic data over piercing points in Antarctica. AUSMEX is also feasible because that reconstruction does not attempt to link pre-Grenville-age blocks and belts of western Laurentia and Australia.