Exploring the Paleosecular variation in Iberia before 1000 BCE: new archaeomagnetic directions from fumiers’ sequences.

The recurrent updating of archaeo- and paleomagnetic databases has allowed the extension of knowledge about paleosecular variation (PSV) in Iberia. However, there is a low number of directional data for the region before ∼1000 BCE. Thus, PSV reconstructions for this period could be biased by data from other regions for older periods. In this work, we present the study of several combustion episodes from three different fumier sequences from Northern Iberia: Abrigo de La Castañera (Cantabria), El Estillín (Burgos), and San Cristóbal (Alava). As a result, 15 new archaeomagnetic directions have been obtained. Most of them contribute to fill the total absence of data in the region ca. 2500-4000 BCE. Two tentative PSV Curves (PSVCs) between ca. 6000 yrs BCE and 1000 yrs BCE are presented, using different modelling techniques. A quality filtering of the mean directions (α 95 ≤ 10°) was carried out to perform the PSVCs. The PSVCs show some differences respect the available reconstructions. These advances in knowledge of PSV are key to improve the archaeomagnetic dating.