Chemical characteristic of duststorm deposits in Harbin and its matter origin
哈尔滨沙尘暴的化学特征及其物质源探讨

The sand dust precipitation was collectied in Harbin city on Mar.20,2002.The paper deals with chemical composition of Harbin dustfall deposits.The result shows that the major elements of SiO_(2)and Al_(2)O_(3) and Fe_(2)O_(3),predominate the dustfall Harbin,occupied 77.8% altogether.The contents of the trace elements such as V,Rb,Nb and Ba evidently are higher than those in Lanzhou dustfall,and the elements of Ni,Cu,Pb,Zn,As and Sr are lower than Lanzhou dustfall.The enrichment factor of Ca,Na and Sr is below 1 being deficit elements,and that of Mg,K,Si,Fe,Mn,P,Ti,Co,Ni and V elements is around 1,derived mainly from lithosphere.Part of Cu,Pb,Zn,Cr and Se is derived from other pollution sources.The enrichment factor of As,Cd and Sb is above 10,derived from pollution sources.The elemental compositions of Lanzhou dustfalls are closer to Lanzhou Loess than Harbin dustfalls,judged from discriminant function(DF) and PI.The Si/Al and Si/(Al+Fe) ratios of Harbin dustfalls are greater than the Earth's surface soils of Northwest China,and chemical weathering degrees of Harbin dustfalls are obviously higher than Lanzhou Loess and Lanzhou dustfalls.Based on the analysis of the chemical composition,discriminant function,PI,cosmid ratio of surface soils and chemical weathering index,the results indicate that element compositions of Northwest Loess are similar to Lanzhou dustfall deposits,while they are obviously different from Harbin sanddust.The source areas of Harbin sanddust differ from Northwest Loess and Lanzhou sanddust,and the status of climate and biology and the degree of chemcial weathering are much better than sanddust sources in Northwest.