Paleomagnetism II
Some rocks show magnetic properties that align with the present geomagnetic field, while others show a reverse alignment. This is taken to indicate that the earth's geomagnetic field has reversed many times during earth history. Patterns of magnetic alignment have been used to correlate geologic layers and to support the concept of plate tectonics. Much remains to be understood concerning the causes and rates of magnetic reversals. Published in Origins v. 10, n. 2.