One of the strongest pieces of evidence for plate tectonics has been paleomagnetism. Evidence has shown, for example, that some rocks in Alaska have magnetic minerals oriented in such a way that they must have been laid down at or near the equator. The fact that they are now at 70° north latitude suggests strongly that the plate on which they are riding must have migrated a very long distance during Earth history.

 

For concept clarity pls visit:  http://science.jrank.org/pages/4990/Paleomagnetism-Paleomagnetism-plate-tectonic-theory.html