2023
Francois Leveque et al., « Potentiels et limites de la prospection géomagnétique appliquée à l'imagerie de sites préhistoriques en zone côtière : le site de Port Neuf (Hoedic) », HAL-SHS : archéologie, ID : 10670/1.z2xuyv
Through a case study of the coastal Mesolithic site of Port Neuf (Hoedic), this article aims to introduce archaeologists to the use of geomagnetic prospection methods in the context of irregular vegetation cover and topography inherent to this type of coastal site. The constraints and limitations of the method are discussed, e.g. the negative influence of pollution by a large metal mass on the information obtained. The data processing carried out to attenuate the disturbance induced by this magnetic pollution does not allow relevant information to be extracted over the entire polluted area. It is also shown that in the context of the presence of dune cover, such as that covering the archaeological levels, it is necessary to study the variation in magnetic field intensity rather than its vertical gradient by gradiometry. The use of other complementary geophysical methods provides information to refine the proposed interpretations, particularly concerning the presence of hearths. For example, electromagnetic methods, such as the use of conductivity meters, provide information on the spatial variation of the substrate's capacity to conduct electricity or a magnetic field at the site scale, or the use of contact sensors, which at the scale of the excavation help to determine areas of potential hearths by detecting zones of magnetic enhancement. The need for archaeologists and geophysicists to work together and for excavators to adopt these tools is discussed.