Eskers in the periphery of their distribution in North Estonia

Abstract

Eskers are frequent landforms in the palaeo-glacial erosional zone. A channelized network of subglacial water conduits above the nonpermeable surface is an obligatory precondition for esker genesis. The current study supports the results of the investigations of modern high-arctic esker formation. The structure and stratification of the esker deposits indicate fast changes and alternation of erosion-transport-accumulation processes. The extent of esker systems over tens or hundreds of kilometres indicates their time-transgressive inherited genesis. The territory of Estonia lies in the periphery of the esker distribution area of the Scandinavian glaciation. Radial eskers in Estonia consist mainly of coarse-grained deposits of local Palaeozoic bedrock. The combination of eskers and glaciokarst kettle holes or glaciofluvial plateaus and kame fields is frequent. The ridge-like glaciofluvial topography, morphologically similar to eskers but formed in stagnant ice is specified as crevasse fillings, and is genetically related to kames.