中文摘要：

通过对岷江上游（源头至紫坪铺水库江段）干流边滩21个现代沉积物样品的磁性特征测试,结果表明：（1）岷江上游边滩沉积物中磁性矿物类型以亚铁磁性的磁铁矿为主,同时含有一定量的菱铁矿和少量的赤铁矿,其中岷江源头处菱铁矿的含量相对较高;（2）磁性矿物晶粒以假单畴（PSD）—多畴（MD）为主;（3）在沉积物磁性特征的空间分布上,茂县至紫坪铺水库河段的磁性矿物含量高于源头至茂县河段,呈逐渐增加的趋势,前者磁性矿物晶粒也明显粗于源头至茂县河段;（4）岷江支流和两岸的滑坡体的汇入及沿程水动力的变化显著影响了岷江干流沉积物的磁性特征。对沉积物的磁性特征研究,为岷江中下游乃至与之相联系的长江河道中利用沉积物磁性特征追踪泥沙来源,重建岷江流域环境演变过程提供基础信息都具有重要意义。

英文摘要：

The Magnetic properties measured from 21 recent sediments on the upper reaches of the Minjiang River（source of the Minjiang River to the Zipingpu reservoir）show that：（1）the sediments are primarily composed of ferrimagnetic magnetite,and contain a certain amount of siderite and a small amount of hematite.siderite in the source of the Minjiang River is relatively high;（2）minerals of pseudo single domain（PSD）to multi domain（MD）dominate the magnetic minerals;（3）concerning the spatial distribution of magnetic minerals,magnetic minerals on the reach between Maoxian to the Zipingpu reservoir are higher than those in the reach between source of Minjiang River to Maoxian,showing a trend of gradually increasing,and the former is relatively coarser.（4）tributaries of the Minjiang River,the landslide on both sides and the hydrodynamic variation along the river are the main factors which influence the magnetic characteristics of these sediments in the mainstream of the Minjiang River.