Elemental Abundances And Distribution In China, Europe And North America Continents

Mineral resources are composed of chemical elements. The environment is affected by the distribution and change of chemical elements and their compounds. It is important to explore resources and assess environment on the basis of the characteristics of elemental contents and their distributions. Based on large-scale geochemical mapping data in the China, Europe and North America continents,the paper has focused on a bundance and distribution of elements in these three continents and their relationship to the natural landscapes and tectonic units. The paper draws following main conculsions.1. The geochemical processes are different in 11 landscapes of China. The background values of most of elements inloess landscape area are very consistent with those in Chinese continental crust.This shows that the elements have no significant change in loess landscape area.However, the elments such as Na₂O, CaO and MgO are apparent lower,and B, Cd, Cr, Co, Cu, Mn, V, Zn, Y, Th and Fe₂O₃ are dramatically enrichedin the South Chinakarst and tropical rain forest areas.2. In different tectonic units element abundance (background) values are different, reflecting the geological backgrounds of tectonic units. W, Sn, Bi and Mo contentsin south China orogeny are much higher than those of other tectonic units. Ag, Pb, Zn and Cu showhigh concentration distribution in the Yangtze craton and south China orogen.The high contentsof As, Sb, Hg mainly distributed in the southwestern margin of theYangtze craton, which are closely related to epithermal mineralization.3. The background values of different major elements are distinct in the tectonic units of European continent, the spatial distributions of SiO₂,Al₂O₃,CaO and Na₂Oare exactly opposite.The mainly reason is that the different type climate characteristics influence them, such as the Central Europe, East European Ukrainian Cratonis rich in Si and poor Al and Fe,while Spain, Portugal and Irish-Scottish Caledonidesare rich in Al, Fe and poor in Si.The spatial distribution of Zn, Pb elements are consistent with the distribution of deposits.In all,the elemental contents of Irish-Scottish Caledonidesare higher than the earth's crust background values, butthe other tectonic units were lower than the background value.The content of Cu and Ni are lower than the background valuesin the most tectonic units.Especially They are the minimum in East European Baltic Craton; while higher in the Irish-Scottish Caledonides and Alpine Orogen.4. W, Sn, Mo, As, Hg, Cd contents of all the tectonic units are higher than the crust background valuesin the North American continent.Generally, the values of cratonare higher than those in the Orogens.But the Cd content of Appalachian orogen is higher than that of the other tectonic units. And the values of Mo, Pb, Zn, Cu and Ni are high in the west America and Alaska of Cordillera Orogen, which is closely related with the deposit distributions.5. The background values of SiO₂, Al₂O₃, Fe₂O₃, K₂O, Na₂O and MgO are highly consistent with their crustal abundances in all three continents. As, Cd, Hg and Sb are obviously enriched, whose enrichment coefficients are more than 2.The heavy metal elements are closely associated with secondary enrichment processes caused by human pollution,mineral resources distribution and mining. F, Mg, Na, Sr were serious secondary dilution compared with crustal abundances, whose enrichment coefficientsare less than 0.5.