Yr 10 Science
Oceanic more of less dense?
More dense
Continental more of less dense
Less dense
Oceanic type of rock
Basalt
Continental type of rock
Granite
Oceanic found where
The bottom
Continental found where
On top of oceanic plate
Oceanic thinner or thicker
thinner
Continental thinner or thicker
Thicker
Oceanic is
continually being made or destroyed
Continental
stays the same for long periods of time
What are some factors that both oceanic and continental have?
Found in the same layer (crust), lithosphere, made out of rock, involved in tectonic activity.
What did Alfred Wegener think and discover?
Continental outlines matched, similar fossils found on different continents/ rock types matched each other, coal found in cold areas + evidence of glaciers found in the tropics.
Why did the other scientists not believe Wegener?
He couldn’t prove how they moved, so scientists couldn’t understand why it happened.
Mid ocean ridge- converging or diverging
Diverging
Subduction zone- converging or diverging
Converging
Collision zone- converging or diverging
Converging
Mid ocean ridge making or destroying plates
Making oceanic
Subduction zone making or destroying plates
Destroying
Collision zone making or destroying plates
Neither
Mid ocean ridge type of plate
Oceanic
Subduction zone type of plate
Both plates
Collision zone types of plates
Continental
Mid ocean ridge evidence for this kind of plate interaction and example of where it occurs in the world.
Young rock- middle of ocean ridge, older rock- further away + Iceland
Subduction zone evidence for this kind of plate interaction and example of where it occurs in the world.
Volcanoes + Pacific ring of fire
Sliding edges evidence for this kind of plate interaction and example of where it occurs in the world.
Earthquakes- San Andreas Fault
Collision zone evidence for this kind of plate interaction and example of where it occurs in the world.
Mountain growing (Mt Everest) + Himalayas
What is a mid ocean ridge
When 2 oceanic plates seperate
What is a subduction zone
Oceanic plate subducts under continental because it is more dense.
What is a sliding edge
Plates moving in parallel and opposite directions. Force builds up in the form of friction, which stops the plates from moving.
What is a collision zone
No subduction occurs. The continental plates are forced upwards and form mountains.
Reasons for tectonic plate movement: Convection currents
Hot magma rises because it becomes less dense, and then cool magma sinks because it becomes less dense. At the top of each cycle, the sideways movement of cooling rock in the mantle cause the movement of tectonic plates above it.
Reasons for tectonic plate movement: Gravity
Gravitational forces cause older materials on the peaks and ridges to sink towards the ocean floor, aiding the movement of the plates because the sinking dense crust drags the rest of the tectonic plate downwards. This is the main cause of plate motion.