arkeomagnetismissä

Arkeomagnetismi, or archaeomagnetism, is a scientific discipline that utilizes the magnetic properties of pottery and fired clay artifacts to determine the age of these objects. When materials containing iron are heated to high temperatures in a kiln, their magnetic mineral grains align with the Earth's magnetic field at that specific time and location. This alignment is then "locked in" as the material cools. By measuring the direction and intensity of the remnant magnetism in an artifact, researchers can compare these readings to established records of how the Earth's magnetic field has changed over time. These records, often derived from studies of archaeological hearths, kilns, and other fired clay features in a specific region, form a "secular variation curve." Matching the archaeomagnetic signature of an artifact to a point on this curve allows for the dating of the artifact. This method is particularly valuable for dating archaeological sites where other dating techniques, such as radiocarbon dating, may be difficult to apply or less precise. The accuracy of archaeomagnetic dating depends on the quality of the artifact's firing, the availability of a well-calibrated local archaeomagnetic reference curve, and the degree of disturbance to the artifact since its original use. It is a field that bridges archaeology and geophysics, providing crucial chronological information for understanding past human activities and settlement patterns.