1. Bernard Brunhes Discovered rocks in France in 1906 with reversed magnetic polarity

3. Cretaceous ‘superchron’

4. Pacific Antarctic ridge Schematic model

5. Drummond Matthews (left) and Fred Vine Cambridge University

6. Magnetic anomalies over the Reykjanes Ridge (S. of Iceland) from Vine & Matthews (1963). Positive anomalies are colored, negative ones are white.

7. Magnetic anomaly patterns acquired by the oceanic crust, while it formed during the Gilbert Reversed Chron (top) and afterwards (from Vine & Matthews, 1963) Gauss Matuyama Brunhes (today) Gilbert

8. Juan de FucaEast Pacific Rise observed mirror image model

9. Relative spreading rates

10. Blanco fracture zone

11. Alfred Wegener

12. Wegener’s map (1910). Note the distortion of India. Map made with a computer (1965).

17. The meaning of an “apparent” polar wander path (APWP).

19. S. Keith Runcorn (1922 – 1995)

20. Computer-generated fit of the Atlantic- bordering continents (Bullard et al., 1965), minimizing gaps and overlaps.

21. Ages of the Ocean floor determined from magnetic anomalies (~ 1990)

22. Late Cretaceous (~85 Ma) map of the world (Scotese, 1981) www.scotese.com

23. Magnetic field during reversals

24. Geodynamo simulations (Glatzmaier and Roberts, 1996) Inner core Outer core High fluid velocity in tangent cylinder

25. Magnetic field lines Close up of inner core