Regularities in the occurrence of protection zones in polygenetic river valleys from the eastern part of the Polish Lowlands

摘要: The occurrence of organic soil cover in river valleys is typical regions that were to areal deglaciation. This feature results from the adaptation a series linear depressions glacial melt-out origin by rivers for their flow. Such depressions, primarily composing overflow lakes, underwent subsequent infilling with mainly lake and marsh deposits. These very thick deposits, characterised high sorption potential developed form continuous structures, can be considered as effective protection layers, isolating groundwater contamination.