Plate Techtonic Vocabulary Flashcards
The proposed supercontinent that 200 million years ago began breaking apart into the modern continents.
Pangaea
The rigid outer layer of the earth, including the crust and upper mantle.
lithosphere
A weak region in the mantle below the lithosphere. Its weakness allows the plates to move.
asthenosphere
Where two plates move apart, resulting in up-welling of material from the mantle to create new seafloor.
Divergent boundary (constructive margin)
Where two plates move together.
Convergent boundary (destructive margin)
Where two plates grind past each other without the production or destruction lithosphere.
Transform fault boundaries (conservative margins)
A relatively higher region 1000 to 4000 miles wide along the divergent boundaries in oceans.
mid-ocean ridge
A deep downfaulted structure along the axis of an ocean ridge.
rift valley
Convergent boundaries are also known as
subduction zones
What ocean plate is begin subducted under the South American plate.
Nazca plate
What plate to the south of Central America is being subducted under the North American plate and the Caribbean plate?
Cocos plate
What small plate is subducting under the US pacific northwest and Canada?
Juan de Fuca plate
What small plate is off the tip of South America?
Scotia plate
