Plate Tectonics Flashcards
What is the age of the earth?
About 4540 million years
What are the oldest rocks on the continent??
3900ma - million years
What are glaciations?
Matching outcrops found in rocks from South America, India and Africa
What is the idea of passive tectonics?
That the plates were carried along convention currents - the mantle motion was what drove this
What is the idea of active tectonics?
The sinking of plates is what drives the process
Why are convention currents not a reason for plate motion anymore? 2 points
No correlation between speed of plate motion and size of the plate
Currents don’t have enough energy
What is ridge push?
The mechanism for is gravity-driven sliding of the plate off the mid-ocean ridge, due to upveiling of magma at the ridge
What is slab pull?
Cold, dense subducting plates are dragged into the mantle by gravity, pulling the rest of the plate downward with it.
