【摘要】 淮河支流颖河上游嵩山东麓丘陵台地与河流阶地一典型全新世黄土-古土壤剖面磁化率、粒度成分和>0.1 mm粒级百分比含量分析结果显示,该地黄土磁化率明显偏低,粒度比黄土高原地区粗,表明该地黄土具有不同的粉尘源区,由不同风力系统形成。深入论证分析揭示出颖河上游黄土是近源风尘沉积物,粉尘主要来源于孟津以东黄河冲积、洪积扇的松散河流沉积物。黄河下游的频繁决口、改道、泛滥沉积为风沙活动提供了丰富的物源,形成风沙活动的动力是东北风。3 100 a B.P.以后气候趋于干旱,黄河下游泛滥频率增加,风沙活动范围扩大,沙尘暴活动强烈。更多还原

【Abstract】 A Holocene loess-paleosol profile is studied on the river terraces,hills and plateau of the east piedmont of the Songshan Mountain in the upper reaches of the Yinghe River as a tributary of the Huaihe River.Higher resolution proxy data of magnetic susceptibility,particle-size distribution and >0.1mm grain-size percentage were obtained from the profile.The results indicate that the magnetic susceptibility of loess-soil sequences in the upper reaches of the Yinghe River was obviously lower than that on the Loess Plateau,but the grain-size was much coarser than that on the middle of the Loess Plateau.It revealed that they were from different dust sources,which belong to different dust transporting systems.On the deep analysis,it is revealed that the loess in the upper reaches of the Yinghe River was dust accumulation mainly from near source,while the coarser dust mainly come from the loose alluvial deposits of alluvial and proluvial fans of the Huanghe(Yellow) River to the east of Mengjin.A rich source of sandstorms were provided by the frequent breaching,diverging and flooding sediments of the Huanghe River.The north-east wind was the driving force of the sandstorm activity.During the late Holocene(3100-0 a B.P.) when the climate was tended to arid,the flooding frequency in the lower riches of the Huanghe River was increasing,the area of dust activity was extending and the sandstorm activity intensity was very strong.更多还原