Meltwater channels and deposits

When the glaciers melted, they fed powerful meltwater rivers. These often followed the courses of the existing river systems. However, in many cases the ice meant that the water was redirected. Many of these meltwater channels are now left dry or contain streams much smaller than the valleys in which they flow. Good examples occur along the southern margins of the Pentland Hills (e.g. at Carlops), the northern flanks of the Cairngorms and around Dinnet on Deeside.

Lakes of icy meltwater

In places, the meltwater spilled into valleys dammed by the ice and formed lakes. The most spectacular example is Glen Roy, where the ice-dammed lake shorelines are still evident as the well-known 'Parallel Roads'. The lakes drained periodically under the ice in great floods.

Distinctive landforms

The deposits from these meltwater rivers frequently form distinctive landforms composed of sand and gravel.

• Along the flanks of the glaciers, 'kame' terraces were deposited (e.g. between Loch Ness and Inverness).
• Under the ice (usually in tunnels), sinuous ridges or 'eskers' were formed (e.g. at Carstairs).
• Beyond the ice margin the debris was laid down in the form of 'outwash' plains or lake deltas (e.g. at Achnasheen).

The vast extent of these deposits in the glens and lowlands in the east and south of Scotland emphasises the contrasts between the landscapes predominantly of glacial erosion in the west and glacial deposition in the east.