Using archaeomagnetism to improve the dating of three sites in Catalonia (NE Spain)

Abstract

Archaeomagnetic dating was performed on four archaeological structures in Catalonia (NE Spain) using magnetic inclination and declination values from three reference curves: the Iberian SVC and two curves computed using the regional SCHA.DIF.3k model and the global SHA.DIF.14k. The results provide new data for discussions regarding the dating of three archaeological sites from three very different periods: Roman, Medieval and Modern. In addition, some considerations were made regarding the usefulness of the three reference curves and the corresponding geomagnetic models. The Iberian SVC suggests that a Roman limekiln near Tarragona was last fired during the 1st century BC, but the archaeomagnetic models suggest it was last fired during the 1st century AD, i.e. closer to the date of the kiln infillings (2nd-3rd centuries AD). All three-reference curves date two structures from an archaeological site to the north of Barcelona to the 10th or 11th century AD. These ages match those determined using radiocarbon ages. Dating a modern limekiln near Girona with a presumed age of more than 200 years produced an inconsistent age when using the Iberian SVC, but plausible ages in the 17th or 18th centuries AD using the archaeomagnetic models. This suggests that the Iberian SVC has been superseded by the regional SCHA.DIF.3k model and the global SHA.DIF.14k model, both of which exhibit excellent dating capabilities. Older archaeological sites, including prehistoric sites, should be investigated to fully exploit and verify the potential of the new SHA.DIF.14k archaeomagnetic model. (C) 2017 Elsevier Masson SAS. All rights reserved.