Glaciated Valley-in-Valley Landscape
This is also known as a ‘glacial valley inside a valley’ landscape. When a glacier erodes a pre-glacial valley and deepens the valley floor, a glaciated valley-in-valley landform is formed. When the glacier retreats after forming the glaciated valley, the river erodes the old glacial valley, causing the formation of a V-shaped valley within the U-shaped valley. When the glacier advances later, the existing V-shaped valley is modified into another U-shaped valley, forming a so-called glaciated valley-in-valley landscape as a result of the two consecutive episodes of glacial erosion.