Archeomagnetic and paleomagnetic dating
Paleomagnetism continues to extend the history of plate tectonics back in time and are applied to the movement of continental fragments, or terranes.
Paleomagnetism relied heavily on new developments in rock magnetism, which in turn has provided the foundation for new applications of magnetism.
The models show a ridge (a) about 5 million years ago (b) about 2 to 3 million years ago and (c) in the present.
Paleomagnetism (or palaeomagnetism in the United Kingdom) is the study of the record of the Earth's magnetic field in rocks, sediment, or archeological materials.
In 1797, Von Humboldt attributed this magnetization to lightning strikes (and lightning strikes do often magnetize surface rocks).
In the 19th century studies of the direction of magnetization in rocks showed that some recent lavas were magnetized parallel to the Earth's magnetic field. Blackett provided a major impetus to paleomagnetism by inventing a sensitive astatic magnetometer in 1956.
However, no systematic relationship between archeomagnetic ages and radiocarbon ages was observed, implying that neither the relocated Japanese PSV data nor the global model accurately represent the Korean secular variation during the archeological period of this study.
At present, archeomagnetic dating in Korea should be carefully applied in conjunction with other dating methods on the consideration of archeological context.