Plate Boundaries Flashcards
What are the 3 different types of plate boundaries?
Constructive AKA divergent
Destructive AKA convergent
Conservative AKA transform
Where do most tectonic events take place?
Most take place at plate boundaries
What occurs at a constructive plate boundary?
Magma rises to fill the rift left by diverging plates and erupts as lava to construct new plate margins
What forms mid-ocean ridges?
Constructive boundary volcanoes e.g. the Mid-Atlantic Ridge
What is an example of a constructive plate margin?
E.g. the Mid-Atlantic Ridge, The North American plate and Eurasian Plate
What happens at a oceanic to continental destructive boundary?
The subducting oceanic plate is destroyed by melting (sinks due to higher density)
An example of a destructive plate boundary?
The Andes (S America) resulting in fold mountains and a volcanic arc
What is an example of a collision boundary?
Continental to continental destructive boundary such as the Himalaya’s creating fold mountains
What is an example of an oceanic to oceanic destructive boundary?
The Antilles in the Caribbean creating a volcanic island arc
What occurs at a conservative plate boundary?
Plate margins are neither constructed no destroyed but rather they are conserved
What is an example of a conservative plate boundary?
The San Andreas Fault in California
What is slab pull?
Another theory of plate movement suggesting that a subducting margin is very heavy so it pulls the plate along behind it
What is seafloor spreading?
Seafloor spreading is another theory of tectonic plate movement due to ridge push, a mid ocean ridge is very heavy so it pushes oceanic margins apart
What provides evidence for plate divergence?
Palaeomagnetism