Identification of the Hydrogeochemical Processes in Groundwater of Gleysols and Retisols Toposequence of the Opalenica Plain

Hydrogeochemical investigation was carried out in the toposequence of Gleysols and Retisols within the Opalenica Plain. Groundwater samples from the study area were collected every two or four weeks from 2002 to 2006 in pre-cleaned 1-L polyethylene bottle from 2 representative wells. The results of research indicated that the quantity of dissolved components in groundwater was connected with wells location in the relief and the properties of soil parent materials. The groundwater of soil located higher in the slope (Retisols) was characterized by smaller concentrations of the analysed components, when compared with the composition of groundwater from lower sites of the slope (Gleysols). The groundwater chemistry is mainly controlled by weathering of carbonate minerals as well as silicate weathering. Moreover, the research results indicate that evaporation process can influence the chemical composition of groundwater in the lower part of the slope.