theory that continents are in slow, constant motion.
the theory that the continents were once a single land mass and have broken apart and “floated” to where they are today
German geologist who first came up with the Continental Drift theory in 1915
name that Wegener gave to the land mass known as the Supercontinent
the longest mountain chain in the world
At the mid-ocean ridge, molten material rises from the mantle, then spreads out, pushing older rock to both sides of the ridge. This process, called sea-floor spreading, forms the new ocean floor.
molten mixture of rock-forming substances, gases, and water that make up the earth’s mantle
magma that has reached the surface; also the rock that’s formed when the liquid lava hardens
a weak spot in the crust where magma has come to the surface
a break in rock where the rocks slide past each other; a break in the earth’s crust; earthquakes occur along faults
the shaking that results from the movement of rock beneath the earth’s surface
the raising of the earth’s crust; usually results in mountain formation
molten rock that has squeezed into existing rock and hardened
Intrusion of mafic rock into granite
process by which the ocean floor sinks back into the mantle
a deep valley that forms where two plates move apart