中文摘要：

根据2004年9月-2005年8月杭州湾北岸中潮滩固定观测点重复采集的表层沉积物的磁学参数和粒度分析,探讨了研究区域潮滩沉积物磁学性质的季节性变化及其对沉积动力的响应.结果表明, 该观测点潮滩沉积物磁学参数存在显著的月际变化,2004年12月底-2005年5月上旬的半年中,SIRM、χARM、χfd%、χARM/χ、χARM/SIRM等参数出现高值,指示了沉积物中含有较多的细晶粒亚铁磁性矿物,对应于潮滩淤积时段和较细的沉积物粒级组成,其余各月上述磁参数值较低,对应于潮滩沉积物较粗的侵蚀期.上述结果表明,沉积物的磁性特征可以很好地反映潮滩冲淤过程中沉积动力的变化.

英文摘要：

This study discussed the monthly variations of northern bank of the Hangzhou Bay and their response to magnetic properties of surface intertidal sediments along the sedimentation dynamics. Forty-nine surface sediment samples were collected at a fixed sampling site in the middle tidal flat from September 2004 to August 2005. The results indicate that magnetic properties of surface sediments vary significantly with month. From late December of 2004 to early May of 2005, the values of SIRM, χARM、χfd%、χARM/χ and χARM/SIRM in surface sediments are relatively higher, suggesting higher concentration of ferrimagnetic minerals with finer grain size. Samples with such magnetic properties occur in the period of tidal flat accretion with a finer sediment particle size composition. For samples from the remai- ning months, the above magnetic parameters have lower values, corresponding to a period of tidal flat erosion with a coarse particle size composition. Therefore, magnetic properties of surface sediments can reflect the changes in sedimentation dynamics during the process of tidal flat accretion-erosion cycle.