Classification and terminology of morainic landforms in Finland

Abstract

The terms assigned to Finnish morainic landforms were frequently originally established for areas where the glacial environment was different from that in Finland. The terms therefore are not always applicable to the conditions found here and there is a need for some revision. Some new proposals are presented in this paper. The term cover moraine could be adopted to refer to a vencer of till, which has a rather flat surface, devoid of transverse or lineal elements. The term ground moraine would then only he applied when the relief is independent of the underlying bedrock topography. As regards the term hummocky moraine, it would he advantageous to subdivide it into at lcast hummocky disintegration moraine, thehummocky squeezed‐up moraine, and the hummocky active‐ice moraine. Today the term is of little value since it is commonly used to describe forms with varied origins.Landforms tend to form groups of closely related genetic assenihlagcs or of complexes where the members are areally related, but often genetically different. It is more logical to handle them as an association of forms, rather than to split the group artificially into a number of separate units. A gradational series of assemblages from a fluting assemblage into a drumlin assemblage and further into a hummocky active‐ice assemblage characterizes the Koillisinaa reference area. A bimodal flow system prevailed during the formation of the landforins. Spiral flow predominates in the formation of flutings and linear drumlins, ahercas up and down movement predominates in the formation of the transverse ridges of Kogen moraine. Between these end members coinhinations of these flow patterns occur.