Preliminary study on the mechanism of the geomagnetic secular variations in Beijing over the last 12000 years

The paleomagnetic secular variation (PSV) in Beijing over the last 12000 ye ars can be divided into long-term (>1000 years) and short-term (500-1000 ye ars) components. The long-term variations are mainly controlled by changes in the drifting field, while the short-term variations are most probably ca used by the fluctuation of the standing field. Comparing to the PSV in Japa n, a remarkable feature in Beijing is a short geomagnetic excursion occurri ng between (5110-4670) +/- 110 years,which might be related with the anomal y movement of the fluid in the Earth's outer core.