Impact Of Soil Parent Materials On Soil Elements Distribution ——With Intermediate-Acidic Instrusive Rock Distribution Area For Example

Soil elements which are distributed over the intermediate-acidic intrusive rock areas of Multi-purpose Geochemical survey range in China are the object of this article.The horizontal distribution characteristics and geochemistry features in deep soils and original rocks of 54 elements in five kinds of main elements,atmophile elements,nutrition elements,heavy metals and trace elements were studied in six administrative areas,and draw the following conclusions:First,the regularities of distribution of major elements in top soils are similar to those in deep soils.The content of SiO2 and Al2O3 is higher in Central south China and East China,but lower in Northwest China;the content of Fe2O3,MgO,CaO and Na2O is lower in Central south China and East China,but higher in Northwest China;the regularity of distribution of K2O is not clear.The mobility order of major elements which deduce from elements stability is:CaO>Na2O,MgO>K2O,Fe2O3>SiO2,A12O3.Major elements in deep soils mainly come from the original rocks,environmental factors such as climate and topography have great influence on MgO,CaO and Na2O during soil-forming process.Second,The regularities of distribution of atmophile elements（F,Cl,S,Br,I）in top soils are similar to those in deep soils,but the difference of element content in deep soils between administrative areas is bigger than that in top soils.Atmophile elements of deep soils inherit the characteristics of original rocks,What’s more,their geochemical behaviour are also limited by environmental factors during soil-forming process.Third,The regularities of distribution of some nutrient elements（C,B,Mn,Mo,Se and pH）in top soils are similar to those in deep soils,these elements are rich in deep soils and mainly come from original rocks.Nutrient elements（N,P,Org.C）which are controlled by bioconcentration in top soils have different distribution regularities between top soils and deep soils.Fouth,The regularities of distribution of heavy metal elements in top soils are similar to those in deep soils,and the elements have great difference in content among areas.The content of Cd,As,Cu,Cr,Co,Ni and Zn is higher in Northwest and Southwest China and lower in Central south China.The content of Pb and Tl is higher in East and Central south China.The content of Hg is higher in East and Southwest China.Heavy metals in deep soils mainly come from original rocks,Cd,Hg,As,Cu,Cr,Co and Ni are controlled by environmental factors（such as rainfall and climatic zone）and have enrichment during soil-forming process.Fifth,The regularities of distribution of trace elements in top soils are similar to those in deep soils,The content of Sn,U,W,Ge,Bi,Th,Nb,La,Zr,Rb,Ce,Ag,Y,Ga and Be is higher in East,Central south and Northeast China,with the content of Au,Sb,Sc,Li,Sr,V,Ba and Ti is lower in East and Central south China.Trace elements in deep soils mainly come from original rocks,and the differences among them in deep soils are mainly controlled by their element mobility.