Landforms associated with Plate Movements Flashcards
When are ocean ridges formed?
when plates move apart in oceanic areas - space between plates is filled with basaltic lava upwelling to form a ridge
What activity occurs along oceanic ridges?
volcanic activity, forming submarine volcanoes
When are rift valleys formed?
when plates move apart on continental areas - areas of crust drop down between parallel faults to form the valley
What is the area between two parallel rift valleys?
a horst - forms an upstanding block
When are deep-sea trenches formed?
where oceanic and continental plates meet, oceanic subducts - forms deep part of ocean called a trench
When is an island arc formed?
during subduction - oceanic plate meets hotter surroundings combined with heat from friction melts the plate - magma rises and forms volcanoes
How are young fold mountains formed?
- continental plates
- move towards each other and forced upwards
- no volcanic activity
