Two Palaeointensity Maxima and Rapid Directional Variation Rates During the Early Iron Age Recorded from Iberian Archaeological Sites. Implications on the Evolution of the Levantine Iron Age Anomaly from Global Modelling: The SHAWQ-Iron Age Model

Variations of geomagnetic field in the Iberian Peninsula prior to Late Iron Age times are poorly constrained. Here we report 14 directional and 10 palaeointensity results from an archaeomagnetic study carried out on 17 combustion structures recovered from six archaeological sites in eastern Spain. The studied materials have been dated by archaeological evidences and supported by radiocarbon dates (8^th-5^th centuries BC). A new full vector Iberian Paleosecular Variation Curve for the Iron Age is presented. Two intensity maxima were observed at Iberian coordinates, the oldest around 750 BC (associated to easterly declinations of around 23º) and the second 275 years later (475 BC) with northerly directions. The related virtual axial dipole moment was up to 14 10 ²²Am² for the oldest materials (750 BC) and reaching 16 10 ²²Am² for the materials corresponding to the end of the Early Iron Age.

In order to investigate the origin of the unusually high fluctuations of the palaeofield we have developed a new global geomagnetic field reconstruction, the SHAWQ-Iron Age model, which is based on a critical revision of the global archeomagnetic and volcanic dataset. The new model provides an improved description of the evolution of the LIAA, which is related to a normal flux patch at the core-mantle boundary below Arabian Peninsula clearly observed at around 950 BC. This flux patch expanded towards the Northwest, while decreasing in intensity, reaching Iberia at around 750 BC. Around 600-500 BC, it underwent a revival bellow the European continent. After that it seems to vanish in situ.