The geomagnetic field changes both in direction (declination and inclination) and in strength (intensity) and archaeomagnetic dating can be based on either changes in direction or intensity or a combination of the two.Dating by direction requires the exact position of the archaeological material in relation to the present geomagnetic field to be recorded, and so the material must be undisturbed and sampled in situ.
These differences in magnetic orientation, which can give us an accurate date, are compared to a known curve of the movement of the earth's magnetic pole.
The curve has been well-documented for Britain, but in many other areas of the world there is a lot less certainty in using this technique.
Reference archaeomagnetic secular variation (SV) curves recently have been proposed for the Iberian Peninsula and may now be used for archaeomagnetic dating.
Example of an archaeomagnetic dating of the last firing of a mediaeval tile kiln, discovered near the church St Gertrude on the market place of Nivelles. : 32-(0)60 39 54 81 Fax : 32-(0)60 39 54 23 Email : This email address is being protected from spambots.
The most probably age of the last heating-cooling cycle is 938 A. obtained by referring to the standard curves of the secular variation of the direction of the field during the last 3 kyr in Paris (Gallet et al., 2002).