U-Shaped Valley

• before glaciation a river runs through a v-shaped valley
• freeze thaw weakens the sides as melted ice gets into the cracks, freezes, and then expands, causing rock to break off
• snow falls in north facing hollows and when compressed it turns into ice
• during glaciation the glacier moves through the v-shaped valley due to gravity
• plucking happens as the glacier freezes onto the bedrock and pulls away loose rock from the valley base/sides
• abrasion deepens the base as the rocks embedded in the glacier scrape against the rock in the valley, scraping it like sandpaper and deepening the base
• after glaciation a huge valley is left with steep side walls and a flat base
• the river will return but will no longer fit the wide valley. this is called a misfit stream
• scree collects at the base of the valley due to weathering
• example of a u-shaped valley: Great Langdale