Download Types of Faults

Types of Faults
Subduction Faults
• Oceanic plate moves under a continental plate
• Large elevation difference between mountains and water
level
• Pressure of oceanic plate sliding underneath, causes the
folding of crust.
• Results in adjacent lands being mountainous
• Ex. the Chile trench is 8 km deep and the Andes are 7km
tall
Subduction fault
Extension Faults
• Two plates pull away from one another
– In the ocean - Molten rock fills in the seafloor
as it spreads apart
Ex. The mid-oceanic ridge is the longest
continuous landform region on Earth
Extension Faults
Extension Faults (cont’d)
• On land: this causes the land to either:
1) sinks as plates move away
- creates rivers and lakes
- e.g. Great Rift Valley in Africa,
Rocky Mountain trench
Rift Valley
Extension Faults (cont’d))
2) Rises as plates move away
(Horst/block Mountains)
eg. Table Mountain in Africa,
Grand Teton in US
Block Mountains
Collision Mountains
• Two plates collide into each other
• Both plates are continental
• No subduction takes place since plates
are the same size and strength
• Continual crushing of the plates create a
crumpling of land which create mountains
• E.g. Himalayan mountains
Collision Faults
Strike-Slip Mountains
• Plates side laterally beside each other
• Often sudden movements which cause
earthquakes and volcanoes
• E.g. San Andreas fault
Strike-Slip Fault
Strike-Slip Faults