1. Map of magnetic anomaly numbers Deep Sea Drilling sites

2. magnetic anomaly number Age (Ma) from geomagnetic reversal chronology extrapolated in South Atlantic assuming constant rate of spreading paleontological age, Ma Seafloor ages from deep sea drilling versus geomagnetic reversal chronology Deep sea drilling in the South Atlantic Ocean

3. Chronology of geomagnetic field reversals magnetic anomaly “number” Ocean floor age, millions of years (Ma), determined largely from deep sea drilling

4. Geologic time scale http://www.geo.ucalgary.ca/~macrae/timescale/timescale.html 4600 My 600 My Age range of modern ocean floor

5. Transform faults

6. 7000 3500 1500 -2500 -1500 -500 0 500 -5500-4500-3500 -6500 South Atlantic Ocean

7. 7000 3500 1500 -2500 -1500 -500 0 500 -5500-4500-3500 -6500 South Atlantic Ocean inactive fracture zone active transform fault active ridge crest

8. inactive fracture zone active transform fault active ridge crest inactive fracture zone

10. Transform faults and fracture zones

11. Map pattern of magnetic anomaly number Deep sea drilling calibration of chronology of geomagnetic field reversals back to 180 Ma. Map pattern of ocean floor age

12. 56 10.9 120.4 anomaly no. 181325313421 M16 M10N M4M0M21M25 154.3180 Age of ocean floor From Muller, et al., 1997