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U-shaped valleys and their features

U-shaped valleys

Glaciers cut distinctive , or troughs, with a flat floor and steep sides. The glacier uses the processes of plucking and abrasion to widen, steepen, deepen and smooth 'V'-shaped river valleys into a 'U' shape.

The in the narrow V-shaped river valley are cut-off by the ice, creating . After , a /river or ribbon lake can sometimes occupy the floor of the U-shaped valley.

Valley floor landforms

Ribbon lakes and misfit streams/rivers

A is a large, narrow lake occupying a U-shaped valley. It forms in a hollow where a glacier has more deeply eroded less resistant rock or it may fill up a valley behind a wall of across the valley.

Misfit streams/rivers through the flat, wide U-shaped floor. They have not eroded the valley, as they formed there after glaciation had carved out the much larger U-shaped valley.