Archaeointensity study of five Late Bronze Age fireplaces from Corent (Auvergne, France)

Abstract : Recent excavations at Corent (France) unearthed a vast Late Bronze Age settlement. The high density of fireplaces especially highlights it. The present study focuses on the archaeomagnetic study of five fireplaces. These ones were dated between 950 and 800 BCE by cross-dating of metallic and ceramic artefacts and by radiocarbon. The main objective of our study is to increase the archaeointensity database in Western Europe at the beginning of the first millennium BCE. The sampling was conducted on 64 fragments of baked clay and sherds from the fireplaces floor. The classical Thellier-Thellier protocol provides 48 successful archaeointensity results, yielding to five mean values between 58 and 69 μT at the site. Together with previously published results, our new data point out two successive maxima of the intensity of the geomagnetic field. The first maximum ~ 70 μT in the ninth century BCE and the second ~ 90 μT in ~ 700 BCE are separated by a ~ 45–50 μT minimum at ~ 800–750 BCE. The resulting fast variation of the field intensity will be very useful for archaeomagnetic dating purposes. As the direction of the geomagnetic field has also a strong variation during this period (Hervé et al. 2013a), archaeomagnetism promises to be a powerful dating tool to recover the historical processes at the transition between the Bronze and Iron Ages in Western Europe.