SEE: Glaciation: 2A.7B: Upland erosional landforms
- Created by: MaggieNaylor
- Created on: 06-03-22 13:57
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- 2A7.B: Erosional UPLAND landforms, associated with cirque/valley glaciers
- Corries: an enlarged hollow with steep back wall and raised rock lip
- 1. Nivation increases the depression in the mountainside
- 2. Plucking at the accumulation zone creates a steep back wall
- 3. Due to the rotational slip of the glacier, there is intense abrasion, scooping out the hollow
- 4. Freeze thaw weathering creates sharp rocks, causing further abrasion
- 5. As the climate warms, the corrie glacier melts and a tarn is left behind
- 4. Freeze thaw weathering creates sharp rocks, causing further abrasion
- 3. Due to the rotational slip of the glacier, there is intense abrasion, scooping out the hollow
- 2. Plucking at the accumulation zone creates a steep back wall
- EXAMPLE: Red Tarn, TLD
- 1. Nivation increases the depression in the mountainside
- Aretes
- Two corries erode back towards each other, forming a sharp ridge
- EXAMPLE: Striding Edge, TLD
- Pyramidal peaks
- Three or more corries erode back to back, and the ridge becomes a peak
- EXAMPLE: Mont Blanc
- Glacial troughs
- A U-shaped valley caused by erosion
- They are straight due to the inflexibility of the glacier
- Formed by abrasion due to basal slip
- Plucking does take place but more selectively than abrasion
- Glacier enters a v-shaped valley then erodes it
- EXAMPLE: Great Langdale Valley, TLD
- A U-shaped valley caused by erosion
- Truncated spurs
- A ridge at the sid of a valley formed by erosion, they are smooth and steep
- Glacier erodes interlocking spur leaving a truncated one. Freeze thaw weathering works further up the spurs to make them smoother
- EXAMPLE: Devil's Point, Scotland
- Glacier erodes interlocking spur leaving a truncated one. Freeze thaw weathering works further up the spurs to make them smoother
- A ridge at the sid of a valley formed by erosion, they are smooth and steep
- Hanging valleys
- 1. There is a smaller u-shaped valley above a larger one caused by a tributary glacier
- 2. The smaller glacier does not have enough energy to erode the valley floor, leaving a hanging valley
- 3. Waterfalls often form here
- 2. The smaller glacier does not have enough energy to erode the valley floor, leaving a hanging valley
- EXAMPLE: Yosemite Falls, California
- 1. There is a smaller u-shaped valley above a larger one caused by a tributary glacier
- Ribbon lakes
- Deep, narrow lake in a glacial trough
- Formed by localised, enhanced erosion
- Enhanced erosion because...
- 1. Weaker bedrock allowing vertical erosion
- 2. Merging of a tributary glacier leading to greater erosion 'cos of increased ice mass
- 3. Narrowing of the valley causing thicker ice + more vertical erosion
- Enhanced erosion because...
- EXAMPLE: Windermere, TLD
- Corries: an enlarged hollow with steep back wall and raised rock lip
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