This study investigates archaeological artifacts from five sites in Europe: one from Switzerland (Cheyres-baked clay remains from an Iron Age kiln: 700-530 BC); one from Bulgaria (Drustur-Medieval kiln: 1200-1300 AD); two from Finland (Busö-Medieval kiln: 1570 AD and bricks from Helsinki: 1906 AD); and one from Russian Karelia (bricks from Valaam: 1856 AD). The goal of the paper is to determine palaeointensity from the archaeological sites mentioned above, as well as to compare the values obtained in different laboratories, and so to infer reliability to the results. Palaeointensity experiments were mainly carried out at the Division of Geophysics, University of Helsinki and at the Palaeomagnetic Laboratory of the Geophysical Institute in Sofia. Additionally, microwave palaeointensity determinations on few sister specimens from Helsinki bricks and from Drustur kiln were performed in Liverpool. Large amount of rock-magnetic studies accompanies the work in order to find possible explanations for the acceptance or failure of palaeointensity experiments. The encountered difficulties in obtaining reliable palaeointensity results are discussed and show a still incomplete state of art for determination of this important ancient geomagnetic field characteristic. The accepted new palaeointensity evaluations for different time and space will partly fill up considerable gaps in European palaeointensity databases. Geophysical inference is demonstrated on the basis of virtual axial dipole moment calculated from the new palaeointensity results and its relationship with the CALS7K.2 model calculation and the observatory measurements for the corresponding territories. © 2007 Elsevier B.V. All rights reserved.
|Journal||Physics of the Earth and Planetary Interiors|
|Publication status||Published - 14 Dec 2007|
- Rock-magnetic study