Environmental Pollution by Heavy Metals in the Soil Resources of Zakhur District, as Examined through Geological Processes

In order to assess soil pollution formed on the alteration zones of Zakhur District, we used 20 ICP-MS analyses. Argillic, argillic-phyllic, advanced argillic, silicic along with Cu, Fe, Pb, Zn, Co, Ni, Au and Ag are the most important decentralized natural resource contaminating agents that have formed extensive heavy/toxic metal haloes in this area. Diverse environmental pollution indices (e.g. geoaccumulation- Igeo, modified contamination degree- mCd and potential ecological risk- RI) show that the leve of environmental pollution risk of Pb is considerable and, as in different alteration zones, quaternary sediments are also very high. Soils highly contaminated with sulfur result in the high sulfide mineralization character of the alteration zones in Zakhur District. Calculations of the mass changes in argillic and silisic zones indicate enrichment by Cr, Ni, As, Pb and S and loss of Hg and Cd. Besides the positive correlation of heavy metals with each other, there are significant correlations between them and Mn and Al which may have occurred due to the adsorption processes by manganese, iron oxides and/or clay minerals.