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In search of a paleomagnetic “smoking gun” for Precambrian plate tectonics. Conclusions: Dipole hypothesis likely OK but not certain Total terrane motion = TPW + individual motion Smoking gun: Match APW paths and geology. from Evans, 2003. TPW on Earth. Richards & Engebretson, 1992 Nature.
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In search of a paleomagnetic “smoking gun” for Precambrian plate tectonics Conclusions: Dipole hypothesis likely OK but not certain Total terrane motion = TPW + individual motion Smoking gun: Match APW paths and geology
from Evans, 2003 TPW on Earth
2101±2 Ma Superior2.22-1.88 Ga MOLSON 1880 Ma Buchan et al., 1998 Halls and Heaman, 2000 Kaapvaal2.22-1.87 Ga De Kock et al., in press
Paleomagnetic success story after McElhinny, 1973
Hoffman, 1988 Nuna: United Plates of America
Smoking gun at 1.8 Ga New synthesis of Slave+Superior 2.1-2.0 Ga 1.96 Ga 1.88 Ga 1.75 Ga
Smoking gun at 1.8 Ga New synthesis of Slave+Superior 2.1-2.0 Ga 1.96 Ga Conclusions: Dipole hypothesis likely OK but not certain Total terrane motion = TPW + individual motion Smoking gun: Match APW paths and geology 1.75 Ga