The Midland Valley: Ice-Moulded Lowlands

The ice moulding of the Midland Valley is a product of ice streaming in the last and earlier ice sheets. The landform evidence of this glacier streamlining is a prominent aspect of urban topography, especially evident in Glasgow’s drumlins and Edinburgh’s crag-and-tail landforms, but is prevalent throughout much of the region in the form of a range of subglacial landforms that also includes drumlinoid drift tails, flutings, ribbed moraine, whalebacks and roches moutonnees. Sequential flowsets derived from the alignment of ribbed moraine and superimposed drumlins record dynamic glacier-flow switches during the last ice-sheet glaciation. Areas comprising both erosional and depositional streamlined forms, typified by the juxtaposition of erosional and depositional crag-and-tail features, are a product of the patchy emplacement of a subglacial deforming layer (till) and represent an important landsystem signature of a mixed (soft and hard) subglacial bed mosaic, which is characteristic of the boundary zone between upland and lowland glaciation.