PALEOMAGNETIC RESULTS

 

- HISTORY OF REVERSALS OF EARTH'S MAGNETIC FIELD WAS ESTABLISHED BY RADIOMETRIC DATING OF VOLCANIC ROCKS FORMED DURING PERIODS OF NORMAL AND REVERSED MAGNETIC POLARITY


- BECAUSE THE MAGNETIC FIELD VARIES WITH LATITUDE, PALEOMAGNETIC MEASUREMENTS SHOW WHERE A ROCK FORMED RELATIVE TO THE MAGNETIC POLE

- FOR EACH CONTINENT, ROCKS OF DIFFERENT AGES GIVE AN APPARENT POLAR WANDER (APW) PATH SHOWING WHERE THE POLE APPEARED TO BE AS A FUNCTION OF TIME (IN FACT, THE CONTINENT MOVED, NOT THE POLE). THESE SHOWED THAT CONTINENTS HAD ONCE BEEN TOGETHER AND MOVED LARGE DISTANCES

- PALEOMAGNETIC STUDIES AT MIDOCEAN RIDGES SHOWED THAT OVER TIME NEW CRUST FORMED AND THEN MOVED APART