Glacial lake Glacial lake A glacial lake is a lake with origins in a melted glacier. They are formed when a glacier erodes the land, and then melts, filling the hole or space that it has created. Near the end of the last glacial period, roughly 10,000 years ago, glaciers began to retreat. A retreating glacier often left behind large deposits of ice in hollows between drumlins or hills. As the ice age ended, these melted to create lakes. This is apparent in the Lake District in Northwestern England where post-glacial sediments are normally between 4 and 6 metres deep. These lakes
Glacial striation provide the abrasive power to cut trough-like "glacial grooves". Finer sediments also in the base of the moving glacier further scour and polish the bedrock surface, forming a "glacial pavement". Ice itself is not a hard enough material to change the shape of rock but because the ice has rock embedded in the basal surface it can effectively abrade the bedrock. Most glacial striations were exposed by the retreat of glaciers since the Last Glacial Maximum or the more recent Little Ice Age. As well as indicating the direction of flow of the glacial ice, the depth and extent of