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Science & Technology in Archaeology

Archaeomagnetometry

Archaeomagnetometry, or archaeomagnetic dating, is a method of dating iron-bearing sediments that have been superheated—for example, the clay lining of an ancient hearth. The process involves tracking changes in the earth’s magnetic field over time and correlating archaeological samples with known past polar positions.

Learn how archaeomagnetic dating works.

Collecting an archaeomagnetic sample from the rim of a hearth: The metal square is cut into the hearth, capturing a cube of sediment that will be sent to the laboratory (the remainder of the square is filled with white plaster to stabilize the sample). Before removing the sample, the archaeologist records the angle of current magnetic north at this precise location, which will be compared with the angle of magnetic north in the past, as revealed by the alignment of iron particles in the sample.