The Earth's magnetic field is subject to variations in intensity capable of leaving their "imprint" in certain heated minerals. An international team exploited this property to reconstruct the magnetic field between the 3rd and 1st millennium BC. BC, thanks to the analysis of iron oxide grains contained in Mesopotamian fired bricks.
Bearing inscriptions with the names of kings, these thirty-two bricks made it possible to precisely date paleomagnetic fluctuations. The researchers were thus able to confirm the existence of the Levantine magnetic anomaly of the Iron Age, a period between 1050 and 550 BC. BC where the Earth's magnetic field was unusually strong in the area of what is now Iraq.
The study, whose first signatory is Matthew D. Howland (Wichita State University, Kansas), was published on December 18 in the journal PNAS of the American National Academy of Sciences. This work suggests that, by taking the method in the other direction, it will be possible to date heated archaeological objects containing grains of iron oxide.
