... composed mainly of fine grained size leading to the waterbearingcapacityisverylow and playsaroleasaquicludes.Besides, in thesefinegrainsizelayers, the contents of arsenic and ironarehigh,especially in darkclay,siltyclayrich in organic ... m.However,dueto the action of oldriversystems, in someplacesthereisnotrace of the finegrainsediments, but there remain only the coarsegrainedsediments of riverbedfacies,whichare of ... intosiltyclay of flood plain, oxbow,coastalswamp and peatfacies in the directionfrom the plainto the modern coastline. The fourth sequenceconsists of swampclay,lagoonalclay and peat. In the directiontowards the center of the plain,each of thesesequencesappearsmore and moreparticular...