This topic covers landforms created by both erosion and deposition. As well as being required to explain how various glaciated features form, you will need to be able to identify these on an O.S map – remember contour patterns are the key to this, you will have handout sheets relating to this in your notes.
Sample answers for all features (erosional and depositional)
PowerPoint used in class for Glacial Erosion Features
Deposition sample answers
Useful deposition revision website
A good summary video of all feature – slightly dry in delivery but excellent content
- Explain the formation of glacial ice and glaciers as a system.
- Explain how glacial ice flows and transports material.
- Describe the processes of plucking and abrasion.
- Explain the formation of the following erosional features with the aid of a diagram… Corries, Aretes, Pyramidal Peaks, U-shaped valleys (troughs), Ribbon Lochs, Hanging Valleys, Roches Moutonnees, Crag and Tail.
- Explain the formation of the following deposition features with the aid of a diagram… Drumlins, Ice-marginal Moraines, Erratics, Outwash Plains, Eskers, Kames & Kame Terraces.
- Identifying features on O.S maps.
Some Key Terms
- Arete – narrow ridge formed between two corries.
- Corrie – arm-chair shaped hollow, usually found on the north-east sides of mountains formed by ice filling a hollow and deepening and steepening the base and back-wall through abrasion, plucking and rotational movement.
- Crag & Tail – Outcrop of rock harder than the surrounding area. The sides of the hard rock (crag) are worn by the glacier. The land behind the crag is protected and forms a long, gently sloping ridge called the tail.
- Drift – Material deposited by a glacier. There are two forms – Till: material deposited under the glacier and Outwash: material deposited by glacial meltwater streams from the debris of the glacier.
- Drumlins – Oval shaped mound consisting of material from the deposits of the glacier. Shape sometimes likened to an up-turned spoon.
- Erratics – Rocks or boulders moved from their original location by a glacier and deposited some distance away.
- Eskers – Long ridges of sand and gravel deposited by rivers flowing under the ice sheet. Material is moulded into the shape of the meltwater tunnel.
- Fluvio-glacial – process by which meltwater deposits/erodes material.
- Glacier – large mass of moving ice.
- Hanging Valley – Suspended on the slopes of a U-shaped valley, it is a tributary of the main valley. Often contains a waterfall.
- Kames – Irregular shaped mounds laid by glacial streams, these are made up of sands and gravel. They can form terraces on the sides of the valley where streams were trapped between the glacier and valley sides.
- Misfit Stream – a narrow river in a U-shaped valley – did not form the valley as it is too narrow, it is a misfit.
- Moraine – Material deposited by glaciers. Different names refer to their location in relation to the glacier. E.g. ‘Terminal Moraines’ are found at the end of the glacier, ‘Lateral Moraines’ are found at the sides of the glacier, ‘Medial Moraines’ formed in the middle of the glacier or where two glaciers meet.
- Roches Moutonnee – Outcrops of harder rock that have been smoothed on the side facing the ice to provide a gentle slope, plucking occurs on the other side to give a more jagged, steeper slope.
- Till – Material deposited beneath a glacier (at the end of it) and made up of boulder clay (as the name suggests!)
- Truncated Spur – A slope which at one point would have jutted out into the valley as an interlocking spur but has since been cut away or eroded by a glacier flowing through the valley.
- U-shaped Valley (glacial trough) – A valley with very steep sides and a flat, wide valley floor. Formed through the erosion of a main glacier flowing through a valley.
Example Exam Questions
- With the aid of annotated diagrams, explain the processes involved in the formation of a corrie (9 marks). Tips: Must have a well annotated diagrams (could be before, during and after glaciation), Explanations should include processes at work e.g. abrasion, plucking, rotational sliding and their resulting effects on the land. Refer to your diagrams throughout.
- Describe the evidence that shows the Great Langdale Valley (map extract) has been affected by processes of glacial erosion (10 marks). Tips: Broadly describe the main features of the glaciated landscape, identify specific features that are formed by glacial processes and provide their names/grid references.