A glacial lake is a lake with origins in a melted glacier. Near the end of the last ice age, roughly 10,000 years ago, glaciers began to retreat.[1] A retreating glacier often leaves behind large deposits of ice in hollows between drumlins or hills. As the ice age ends, these will melt to create lakes. This is apparent in the English Lake District in Northwestern England where post-glacial sediments are normally between 4 and 6 meters deep.[2] These lakes are often surrounded by drumlins, along with other evidence of the glacier such as moraines, eskers and erosional features such as striations and chatter marks.
The scouring action of the glaciers pulverizes minerals in the rock over which the glacier passes. These pulverized minerals become sediment at the bottom of the lake, and some of the rock flour becomes suspended in the water column. These suspended minerals support a large population of algae, making the water appear green.[3]
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