GEOMAGNETIC SECULAR VARIATIONS AND CLIMATIC CHANGES SINCE 15,000-A-BP, BEIJING REGION

A sediment sequence, from Fangshan in the Beijing Basin, has been samp led for paleomagnetic studies. The 1430 paleomagnetic samples possess a strong and stable magnetic remanence. A high-resolution record of se cular variation in North China over the past 15 ka B. P. has been prov ided. Spectral analyses have shown that main periods of inclination, d eclination and relative intensity are about 1000, 2000 and 4000 a; 800 , 1640 and 3300 at and 820, 1200, 2200 and 3300 a; respectively. Two e xcursions have been discovered, and the correlation between the geomag netic intensity variations and the climatic changes has been discussed .