Further Evidence of High Intensity During the Levantine Iron Age Anomaly in Southwestern Europe: Full Vector Archeomagnetic Dating of an Early Iron Age Dwelling From Western Spain

Abstract

We report an archeomagnetic study from the Early Iron Age archeological site of Cerro de San Vicente (Salamanca, Spain). The studied materials were sampled from one roundhouse and its central fireplace, a surrounding burnt floor, and slags with a twofold objective. First, to archeomagnetically determine the last use of the central fireplace, because dating with other methods was imprecise. Second, to retrieve information about the Earth's magnetic field in Western Europe from a period when the Levantine Iron Age Anomaly (LIAA) has been occasionally reported. This study includes mineralogical, archeomagnetic directional analyses, and multimethod archeointensity determinations. Paleomagnetic analyses of the central fireplace yield a mean direction: declination D = 15.1°, inclination I = 52.5°; k = 477.1, and α95 = 5.6°. Archeointensity determinations yield a mean anisotropy-corrected archeointensity of 72.4 ± 2.0 μT (74.7 ± 4.3 μT if a pTRM-check correction is applied) on the central fireplace and 48.2 ± 2.0 μT on slags. A full-vector archeomagnetic dating was performed with the SHA.DIF.4k geomagnetic field model which yielded an age interval of last use of the central fireplace between 644 and 575 BCE (654–575 BCE with the pTRM-check corrected data) at 95% confidence level. This date agrees with the archeological context. Results allows to place the high paleointensity obtained near the maximum observed in Iberia at this age, confirming the existence of this peak related to the LIAA in Western Europe where records of this feature are still scarce.