Archaeomagnetism
Archaeomagnetism and palaeomagnetism are two important geophysical methods used to study the history of the Earth's magnetic field through different periods. These methods provide powerful tools for dating and reconstructing changes in the Earth's magnetic field, and contribute significantly to our understanding of the Earth's geological and archaeological history.
Rocks, sediments and baked material contain tiny magnetic minerals that become magnetised during rock/sediment formation or during cooling from high temperatures. This magnetisation lasts over millions of years (remanent magnetisation) and is aligned parallel to the ambient magnetic field at the time of acquisition.
Archaeo- and palaeomagnetic measurements are used for:
- Dating of archaeological sites
- Dating of geological sequences (magnetostratigraphy)
- Reconstruction of continental and local tectonic movements
- Reconstruction of the Earth's past magnetic field and its analysis, e.g. during geomagnetic polarity reversals