STUDY SHEET PLATE TECTONICS
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What is a divergent plate boundary?
A: When 2 plates move apart <----->
What forms when 2 oceanic plates diverge <----->
A: Mid-oceanic ridge (volcanoes on ocean floor)
What can form when 2 continental plates diverge <---->
A: Rift valley and fault block mountains
What is seafloor spreading <----->
A: When ocean floor spreads away from mid-ocean ridges <----->
What is a convergent boundary?
A: When 2 plates collide 
What forms when 2 continental plates converge 
A: Folded mountains
What forms when a continental plate collides with an oceanic plate? 
A: Subduction, then trench, then volcanic mountains
What forms when one oceanic plate collides with another oceanic plate? 
A: Subduction, then trench, then volcanic mountains
What is subduction?
A: When oceanic plate dives below continental plate and melts. This melted rock can rise up to
form volcanic mountain.
What is a trench?
A: Deepest part of the ocean formed at a convergent plate boundary
What is a transform boundary?
A: When 2 plates slide past each other
What occurs at transform boundaries?
A: Earthquakes
Where is the oldest oceanic crust/rock found?
A: Close to subduction zones
Where is the youngest oceanic crust/rock found?
A: Close to mid-ocean ridge
How does age of rocks support seafloor spreading?
A: New rock formed at mid-ocean ridge then moves toward trench as it ages
How do magnetic reversals in the rock support seafloor spreading?
A: We see the reversals recorded in the rocks along ocean floor
What powers plate tectonics?
A: Convection in the mantle
How can fossils support plate tectonic theory?
A: Large animals cannot swim across oceans, so perhaps continents were once connected
(Pangaea)
How does rock evidence support plate tectonic theory?
A: Similar rocks match up across the continents
How do puzzle pieces support plate tectonic theory?
A: Continents today looks like puzzle pieces
How do glaciers support plate tectonic theory?
A: We see evidence of past glaciers in places too warm now. Maybe continents moved.