Booklet 3 Flashcards
Ice cover across UK in the last ice age
Vast ice sheets in north and north-east in mountainous areas
I don’t really think we need to know this cause. I think it will have like a picture if it’s in there so you can look at
Glacial processes
Freeze thaw weathering
Erosion
Movement and transportation
Deposition
Freeze Thor weathering
Water enters the crack of the rock. It freezes and expands enlarging the craic seeps deeper refreezes.
After many repeated cycles to rock, fragments, breakaway
Erosion
Abrasion where Angular rocks, beneath the glazier, and scratch the underlying bedrock the present of melt water beneath the glaciers, important as it helps to lubricate the eyes as it grinds forwards
Plucking meltwater beneath the ice freezes and bonds pieces of loose bedrock to the glacier. When did lazy move forward these loose pieces of rock up, locked away from the bedrock, leaving behind very jagged and angular surface.
Play some movement and transportation
Basil slip– melt water in with a glacier, enables it to slide forward as a must buy a few meters a year
Glaciers can advance or a retreat
Glaciers advance when the amount of additional snow and ice accumulation in a year, exceeds the amount of melting
Play seal treat occurs when the amount of ablation exceeds accumulation 
Bulldozing
When are glacier moves forwards? It acts like a bulldozer bulldozer parts of rock. Debris increasingly Highridge, called a moraine
Rotational slip
The circular movement of ice in a Corrie
Glacial deposition
When t water takes place near the snout of the river the sediment is dumped on the ground -till
Outwas deposited in front of glacier
How is a Corrie formed
Snow collects in a sheltered hollow on the side of a mountain. This is usually on north-facing slopes in the Northern Hemisphere. The snow doesn’t melt in the summer because it is high up, sheltered and cold.
Every winter, more snow collects in the hollow. This becomes compacted and the air is squeezed out, leaving ice.
The back wall of the corrie gets steeper due to freeze-thaw weathering and plucking.
The base of the corrie becomes deeper due to abrasion.
As the glacier gets heavier it moves downhill. The glacier moves out of the hollow in a circular motion called rotational slip.
Due to less erosion at the front of the glacier a corrie lip is formed.
After the glacier has melted a lake forms in the hollow. This is called a corrie lake or tarn.
Characteristics of a Corrie
arêtes - this is a narrow ridge of land that is created when two corries erode back towards each other
pyramidal peak - if three or more corries erode back towards each other, at the top of a mountain a pointed peak is left behind
Other features of erosion
Other landforms resultant from erosion
When a glacier moves downhill it erodes everything in its path through abrasion and plucking. Glaciers usually follow the easiest route down a mountain, which is often an old river valley. Interlocking spurs created by a river are eroded at the ends by the glacier to create truncated spurs. After the glacier has melted it leaves a U-shaped glacial trough. Sometimes the glacial trough fills with water, called a ribbon lake. Old tributaries, which would have once fed into the valley are left suspended and are known as hanging valleys.
Landforms result from transportation and deposition
Erratics
Drumlins
Moraines
Erratics
these are rocks that have been deposited by the glacier. They are usually made of a rock type that would not be found in that area. This suggests that erratics can be carried a long way from an area of different geology.
Drumlins
glaciers can move moraine around in unusual ways which produce interesting features. Drumlins are mounds of deposited moraine. They have a steep side and a sloping side. They can be small or large. They are sometimes described as having a ‘basket of eggs’ topography because of the unusual landscape they create.
Moraines
ny material carried or moved by a glacier is called moraine. There are three different types of moraine:
Lateral moraine - material deposited along both sides of the glacier. This moraine is usually made up of weathered material that has fallen from the valley sides above the glacier.
Medial moraine - material deposited in the middle of the glacier. This is caused by the lateral moraines of two glaciers when they meet.
Terminal moraine - material deposited at the end of the glacier.
