Mountain Landforms

Destructive Plate Boundary

• Oceanic and continental plates collide
• Oceanic plate goes underneath the contintental plate
• Because it is denser (subduction)
• Oceanic plate melts as it pushes down into the mantle
• The continental plate forms a fold mountain

e.g. the Andes 

Collision Plate Boundary

• 2 continental plates push into eachother
• The plates are the same density
• The plates crumple and build up pressure
• The pressure causes the plates to push upwards
• This upward force creates a fold mountain

e.g. the Himalayas

Corrie - A steep sided hollow deepened by the action of ice

• Freeze thaw weathering occurs on cliffs above the glacier, pieces of rock are broken off
• Plucking occurs on the backwall of the glacier
• Glacier moves away and downhill
• Moraine (rocks) are deposited at the end of the glacier
• Abrasion of moraine, dragged by glacier erodes the floor

Pyramidal Peak

• A mountain top carved/steepened by weathering and erosion
• Cirques are formed around the pyramidal peak

Arête

• A sharp ridge formed where 2 cirques cut back into a mountain
• Backwalls retreat due to freeze thaw weathering and plucking
• The arête becomes narrower

Hanging Valley

• A high level tributary valley with a sharp fall to the main valley
• Formed due to glacial erosion

Glacial Trough/U-Shaped Valley

Formed due to glacial erosion

• Plucking on the back walls of the glacial trough and abrasion
• Interlocking spurs are truncated as the gacier cuts straight through the landscape
• Between truncated spurs are hanging valleys which have not been eroded as deeply as the main valley

Moraine

When material is transported - formed due to deposition

• Glacial ice melts
• Rocks that have been carried by the glacier are deposited
• Terminal moraine - found at furthest point reached by a glacier
• Lateral moraine - deposited along the sides of a glacier
• Medial moraine - found at the junction between 2 glacier

Ribbon Lakes

Formed due to deposition and erosinal processes

• Long, narrow lakes found on the valley floors of glacial troughs/u shaped valleys
• deposits down a valley and causes a lake to build on the valley floor
• Areas of soft rock in the valley may be eroded more easily - deeper sections fill with water and become lakes
• Deposition of moraine across the valley can also act as a dam, trapping the water and creating a ribbon lake

Erratics

Formed due to deposition

• Large stones/boulders moved by the glacier to an area where the underlying rock does not match
• They have been transported and deposited by a glacier 
• Useful indicators of patterns of former ice flow

Drumlins

Formed due to deposition

• Egg shaped hills
• Formed when ice became overloaded with sediment
• Elongated features that can reach a kilometre or more in lenght, 500m in width and 50m in height
• Caused when the ice tries to move around an obstacle and material builds up around it