POTENTIALLY TOXIC ELEMENTS OF VOLCANIC ASH SOILS IN THE CAPPADOCIA REGION OF CENTRAL TURKEY

We determined the variability and content of potentially toxic elements (PTEs) in soils formed on volcanic parent materials erupted from Erciyes stratovolcano in the middle Anatolian region of Turkey. The PTE content of soils formed on tuffs were higher than the soils formed on lavas. All the PTE concentrations decrease with increasing soil depth except for those of Cd. Cr, Cd, and Ni increased with elevation, but Co, Cu, Mn, Pb, and Zn concentrations decreased. The high PTE concentrations in soils could be attributed to the volcanic parent materials. The greatest PTE variations in soils were determined by lithological differences and could be attributed to the types of parent material and their compositions. Site specific soil management practices must be applied to soils in the study area because of the high PTE content.