Spatial distribution of archaeomagnetic vectors within archaeological samples from Eisenerz (Austria)

Abstract

SUMMARY The archaeological site near Eisenerz in Upper Styria (Austria) called the Copper Smelting Site S1, was used for copper smelting in the Middle Bronze Age (15th–13th century BC). The dating of the site is based on pottery finds and has been confirmed by radiocarbon dating. Samples of several roasting hearths and furnaces have been collected and consolidated in order to investigate the spatial distribution and the stability of the magnetization of these materials. Around 500 specimens have been obtained for which the natural remanent magnetization (NRM) and the magnetic susceptibility have been measured with a 2G Squid cryogenic magnetometer and a GEOFYZIKA KLY-2 susceptibility meter, respectively. Variations of the NRM and magnetic susceptibility with depth indicate the layer of heating and give some first evidences about the use of these soils during the smelting procedure. Higher values of the intensity of the magnetization as well as of the magnetic susceptibility correspond to the more intense heated layer. Magnetic cleaning (thermal and Af demagnetization) has been performed in pilot samples and revealed the presence of a stable component of the magnetization. The examined types of material are suitable for archaeomagnetic investigations. The record and the preservation of all the necessary magnetic information provide important knowledge concerning the recent history of the Earth's magnetic field.