ALBERT

Beschreibung: To understand the global geomagnetic field behaviour is necessary to describe its changes at regional scales. For this reason, one of the most important challenges of the archaeomagnetic research is to improve the spatial and temporal coverage of directional and intensity archaeomagnetic data. In this context, we present here the first full-vector archaeomagnetic data from Central Asia derived from the study of 9 archaeological kilns sampled in South Uzbekistan, with ages ranging between 200 BCE and 1400 CE. Thermal and AF demagnetizations and Thellier-Thellier experiments were performed to obtain the full-vector data. Paleointensity experiments include pTRM checks, TRM anisotropy and cooling rate corrections. The comparison between the new data and global geomagnetic field models shows an important deviation from predictions between 200 BCE and 200 CE, especially for the geomagnetic field intensity element. This geomagnetic feature is analysed to determinate its dipolar or non-dipolar character. Both the pole position and virtual axial dipole moment estimations derived from our new data and from the SHAWQ2k model show important discrepancies for the interval 200 BCE – 200 CE, suggesting a non-dipolar origin for the studied feature. Finally, the analysis of the radial magnetic field at the core-mantle boundary and the non-dipolar intensity at the Earth´s surface shows a reversal flux patch for this time window, explaining the low intensities observed in Central Asia for these ages.