Paleomagnetism Paleomagnetism is the study of the fossil magnetism in rocks. It has been paramount in determining that the continents have drifted over the surface of the Earth throughout geological time. The fossil magnetism preserved in the ocean floor has demonstrate. Paleomagnetism refers to the strength and orientation of the earth's magnetic field at some remote past time. Magnetic field reversals are recorded in deep ocean bottom materials which show that at some ancient times the earth's magnetic poles have reversed, north pole becoming south pole and south pole becoming north pole. Paleomagnetic data are useful in many applications in Earth Science from determining paleocurrent directions to analyzing the long-term behavior of the geomagnetic field.