Research activities in archaeomagnetism are carried out on two distinct sites: directional measurements of the geomagnetic field are made at the National Magnetic Observatory in Chambon-la-Forêt, in the Loiret, while measurements of geomagnetic intensities are made at IPGP in Paris.
Measurements of the archaeo-directions are carried out using a rotational inductor adapted to the decimetric size of the samples analyzed (photo left). The experimental protocol used, derived from the work of Emile Thellier, is based on magnetic dragging experiments. A description of the method, which preserves the advantage of the high precision of the orientation of the samples made in the field, can be found in Le Goff et al. (2020).
Our geomagnetic intensity studies are performed using a vibrating sample magnetometer called Triaxe, built in the laboratory, which allows continuous measurement of the magnetization of a small volume sample (less than 1cm3) at varying temperatures up to 650°C, in field or in zero field (right photo). Our archaeointensity results are thus obtained using an experimental protocol developed specifically to take advantage of the Triaxe’s capabilities (for its description, see the article by Le Goff and Gallet, 2004). Three such magnetometers are available at IPGP, including one belonging to the Laboratoire d’Archéologie Moléculaire et Structure (LAMS, Sorbonne University).
Our research, carried out for the most part in close collaboration with LAMS (Agnès Genevey), is based on numerous collaborations established with various archaeological research services (universities, departmental or regional archaeological services, Inrap, Eveha, Archeodunum).