Flashcards in Chapter 8.3 Deck (13)
The theory concerning the movement of the continental plates
Circular movement that occurs when warmer, less dense fluid particles rise and cooler, denser fluid particles sink
the plates of the Earth's crust that make up the land. 30-70km thick
one of the types of crust that makes up the Earth's outer layer. Oceanic crust is thinner than continental crust and made up of dense, heavy rocks such as basalt. On average they are 6km thick
The edges of tectonic plates.
process in which two tectonic plates push against each other, and oceanic crust sinks below the less dense continental crust.
Destructive Plate Boundaries
A convergent boundary where two plates collide.
Constructive Plate Boundary
plate that creates new land from cooling magma.
One of the two smaller continents created when the supercontinent Pangaea broke apart about 200 million years ago.
one of the two smaller continents created when the supercontinent Pangaea broke apart about 200 million years ago.
A localised place where an activity occurs.
Why do the plates move?
The plates move because heat causes the partially molten rock in the mantle to expand and rise towards the surface. It spreads out, cools and falls back under the force of gravity. This creates a convection current that keeps the plates moving slowly.