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