Esker

• Eskers are meandering ridges along a valley floor formed by meltwater streams in a glacier.
• Eskers are made up of meltwater sands and gravels, which are sorted by size because heavier stones are dropped first by flowing water.
• The stones in eskers tend to be more rounded than glacial deposits, because of the action of flowing water rounding the edges by erosion.
• When a glacier begins to melt, sub-glacial streams deposit in the tunnels.