Geologic History 3
Terms in this set (31)
The theory that pieces of Earth's lithosphere are in constant motion, driven by convection currents in the mantle
A section of the lithosphere that slowly moves over the asthenosphere,carrying pieces of continental and oceanic crust.
The hypothesis that the continents slowly move across Earth's surface.
Lava that flows from undersea rift zones that produce mountain chains.
A deep valley along the ocean floor beneath which oceanic crust slowly sinks toward the mantle.
where the crust is sinking down into the Earth
earths crust located under the ocean
earths crust made of land
A plate boundary where two plates move away from each other.
Can create: Mid-ocean ridges, rift valley, volcanic eruptions
A plate boundary where two plates move toward each other. The 3 types are:
continental/continental, continental/oceanic, and oceanic/oceanic.
Can create: trenches, volcanoes, mountains
A plate boundary where two plates move past each other in opposite directions.
The name of the landmass within the theory of continental drift and plate tectonics that
all of the continents were once all joined 245 million years ago
A weak spot in the crust where magma has come to the surface.
molten rock that has erupted onto the Earth's surface
molten rock below the Earth's surface
hot spot volcano
A volcanically active area of Earth's surface far from a tectonic plate boundary.
The sudden movement of the lithosphere due to the push, pull or slip of tectonic plates
A break in Earth's crust where masses of rock slip past each other.
The thin and solid outermost layer of the Earth above the mantle
the layer of rock between the Earth's crust and core
The central part of the earth below the mantle
the solid, outer layer of the earth that consists of the crust and the rigid upper part of the mantle
The soft layer of the mantle on which the tectonic plates move
The strong, lower part of the mantle between the asthenosphere and the outer core
Hot rock from deep within the Earth rises, but cooler rock near the surface sinks causing the lithosphere (tectonic plates) to move
Forms when magma explodes from a volcano and solidifies in the air or from powerful
eruptions that shatter existing rock. Consists of volcanic bombs, volcanic blocks, lapilli,
and volcanic ash. Range in size from tiny particles and boulders the size of homes.
Ring of Fire
The area around the Pacific Ocean because of the number of volcanoes and earthquakes
due to subduction of tectonic plates. Contains over 75% of the world's volcanoes and
90% of the world's earthquakes.
A deep valley that forms where two plates move apart
due to convergent plate boundaries where portions of the Earth's crust cause uplift.
due to a divergent plate boundary where rock breaks and drops down relative to one another.
created when magma rises to the surface repeatedly and builds up.