1.2b Flashcards
1
Q
3 types of plate boundaries
A
Divergent (constructive apart)
Convergent (destructive towards)
Conservative (transform sliding)
2
Q
How are mid-oceanic ridges formed
A
Plates move apart in oceanic areas
As magma cools, it solidifies to form dense new basaltic rock and new oceanic crust is formed at submarine volcanoes, which may become ridges or islands if they continue to erupt
3
Q
What are rift valleys
A
When lithosphere move apart in continental areas, central sections drop down to form rift valleys
4
Q
Why do convergent continental, continental form fold mountains
A
Continental plates are lower density than asthenosphere beneath them.
Subduction does not occur so no volcanic activity
