1. 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

2. TPW on Earth
from Evans, 2003
wholesale migration of solid Earth relative to spin axis & mag field (assumed GAD).

3. Richards & Engebretson, 1992 Nature
Complete the observations: geoid, hotspots, subduction zones, and L.M. tomography
Richards & Engebretson, 1992 Nature

4. from Evans, 1998, EPSL v.157, p.1-8

5. Supercontinent – TPW predictions

6. TPW legacy

7. A common TPW axis
Gondwanaland not assembled until Cambrian. Then why write 700 Ma?

8. Buchan et al., 2000

9. Superior 2.22-1.88 Ga Kaapvaal 2.22-1.87 Ga
2101±2 Ma
MOLSON
1880 Ma
Buchan et al., 1998
Halls and Heaman, 2000
Kaapvaal Ga
De Kock et al., in press

10. Paleomagnetic success story
after
McElhinny, 1973

11. Nuna: United Plates of America
Hoffman, 1988

12. Smoking gun at 1.8 Ga New synthesis of Slave+Superior 2.1-2.0 Ga

13. Smoking gun at 1.8 Ga New synthesis of Slave+Superior 2.1-2.0 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