Upper Jaramillo polarity transition and short geomagnetic event recorded in a loess section at Jingbian, northern China

Detailed rock-magnetic and paleomagnetic investigations have been carried out in a loess-paleosol sequence from the lower part of unit S9 to the bottom of L11 at Jingbian (37.4° N, 108.8°E), which demonstrates that the Upper Jaramillo polarity reversal and a short geomagnetic event bounded within the Jaramillo normal subchron have been revealed. The duration of this short event was about 8.5 ka. The statistical analysis showed that the virtual geomagnetic poles (VGP) paths of the short geomagnetic event are predominantly situated in the longitudinal sector over the America continent and its antipodal longitudes. While the VGP paths of the Upper Jaramillo recorded in the same loess-paleosol sequence exhibit a tight cluster located at western Australia.