Geomagnetic stratigraphic dating
Paleomagnetism continues to extend the history of plate tectonics back in time and are applied to the movement of continental fragments, or terranes.
A common form of chemical remanent magnetization is held by the mineral hematite, another iron oxide.
Although he produced an abundance of circumstantial evidence, his theory met with little acceptance for two reasons: (1) no mechanism for continental drift was known, and (2) there was no way to reconstruct the movements of the continents over time.
Keith Runcorn constructed apparent polar wander paths for Europe and North America.
Magnetic signatures in rocks can be recorded by several different mechanisms.
Iron-titanium oxide minerals in basalt and other igneous rocks may preserve the direction of the Earth's magnetic field when the rocks cool through the Curie temperatures of those minerals.
The record of geomagnetic reversals preserved in volcanic and sedimentary rock sequences (magnetostratigraphy) provides a time-scale that is used as a geochronologic tool.