Erosional origin of drumlins and megaridges
The erodent layer hypothesis (ELH) proposes that drumlinization is primarily an erosional process that leaves no substantial stratigraphic
record because it cuts a streamlined unconformity surface across pre-existing bed materials. A review of the literature and use of appropriate
examples of glacially-streamlined terrains from North and South America and Europe, confirms that many (most?) drumlins are residual
features made of antecedent sediment or rock and ‘grew down’ into the underlying bed of ice sheets as a consequence of abrasion by a layer of
deforming subglacial debris.