COMPARISON OF GEOCHEMISTRY OF METALS IN SEDIMENTS FROM SOME TYPICAL ROCK AREAS
若干典型岩性区域沉积物金属元素地球化学特征比较研究

Total contents and speciation of metals (Li,Na,K,Ca,Sr,Ba,Ti,V,Cr,Mn,Fe,Co,Ni,Cu,Zn,Al) in sediments from four typical rock areas of shales,limestone,granite,and loess were studied.Both the contents and speciation in sediments are different among the rock areas.Compared with the other rock areas,sediments in the loess area have high contents of mobile elements,but low contents of immobile elements.Metals in sediments of the loess area reside mainly in residual form,while the contents of organic,oxide,and exchangeable forms are relatively low.Contents of heavy metals in sediments from the limestone area are high,but those of immobile elements,such as Na and Sr,are low.The residual fractions of metals in sediments from the limestone area are not low,showing that the metals released by weathering have taken part in the formation of secondary minerals,and thus being enriched.Heavy metal contents in sediments from the granite area are moderate,but Fe and Al contents are rather high.Contents of the residual forms of metals in the granite area are not high,which is related with strong weathering forces.Contents and speciation of metals in sediments from shales area are moderate,showing average state of all rock areas.