HR: 10:35h
AN: GP21D-02 INVITED     [PDF]
TI: Aeromagnetic and satellite magnetic data guide reconstructions of parts of Rodinia
AU: * Finn, C
EM: cfinn@usgs.gov
AF: U. S. Geological Survey, MS 964, Denver Federal Center, Denver, CO 80225 United States
AU: Pisarevsky, S
EM: spisarev@tsrc.uwa.edu.au
AF: University of Western Australia, Tectonics Special Res Ctr 35 Stirling Hwy, Crawley, WA 6009 Australia
AB: Numerous reconstructions of the ~1100-750 Ma supercontinent of Rodinia have been proposed, but there is little agreement on any firm points of comparison (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 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. Recently released satellite magnetic and continental-scale aeromagnetic compilations can be used for plate-tectonic scale reconstructions as well as for 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 consistent with the data, but cannot be fully tested due to the lack of critical magnetic data over piercing points in Antarctica. Because the AUSMEX reconstruction does not attempt to link pre-1100 Ma crystalline blocks and belts of western Laurentia and Australia, the aeromagnetic data are not useful for its evaluation.
DE: 0925 Magnetic and electrical methods
DE: 1517 Magnetic anomaly modeling
DE: 8110 Continental tectonics--general (0905)
DE: 9619 Precambrian
SC: Geomagnetism and Paleomagnetism [GP]
MN: 2003 Fall Meeting