PEDO-GEOCHEMICAL DIFFERENCES BETWEEN YOUNG SOILS: REGOSOLS AND SPOLIC TECHNOSOLS IN NORTHERN PART OF EASTERN CARPATHIANS (ROMANIA)

Based on four young soil profiles (P), wherefrom two are situated on mining dumps (spolic technosols, P1, P3) and the other two are closely located (skeletic regosols, P2, P4) on slopes of 30, it has been analysed the morphologic differences, the content of artefacts and the concentration of environmental relevant metals. Spolic technosols are characterised by a large content of artefacts (max. 70.9%) with profile variations while in regosols the skeleton content is slightly lower (up 65.3%), but increases steadily with depth. The high frequency of freeze-thaw cycles (88) compared with the high mountain area (70) accelerates pedogenesis, by fragmenting the anthropogenic spolic material (MAsp). The technosol formed by alteration of pyrite and chalcopyrite (P2) has maximum concentrations of following specific trace elements like Ni (158 mg kg(-1)), Cu (696 mg kg(-1)), in bioaccumulative horizon, and Se (43.5 mg kg(-1)) in lower part of soil profile exceeding the benchmarks of the Romanian legislation. By weathering manganese carbonates and silicates, the second technosol (P3) has the maximum amounts for Ni (210 mg kg(-1)), Cu (395 mg kg(-1)), Pb (792 mg kg(-1)), Se (74.9 mg kg-'). In the topsoil of regosols, only Ni and Se are beyond the average values specified in literature. In all the studied profiles, Mn shifts to minor elements class while Fe into the major elements class. The chemical properties of the pyrite dump favoured the installation of acidophil vegetation that contrasts with the surrounding soils (regosols).