What is fossils.
The preserved remains of ancient organisms.
What is midocean ridge.
An undersea mountain chain where new ocean floor is produced; a constructive (divergent) plate boundary.
What is the theory of plate tectonics.
The theory that links together the ideas of continental drift and ocean-floor spreading and explains how the Earth has changed over time.
What is a trench.
A V-shaped valley on the ocean floor where old ocean floor is subducted; a destructive (convergent) plate boundary.
What is a convergent boundary.
A plate boundary at which plates come together.
Who is Alfred Wegener.
German Scientist who came up with the theory of continental drift.
What is ocean-floor spreading
The process I which old ocean floor is pushed away from a midocean ridge by the formation of new ocean floor.
What is tectonics.
The branch of geology that deals with the movements that shape the Earth's crust.
What is subduction.
The process in which crust plunges back into the interior of the Earth.
What is a strike-slip boundary.
A plate boundary at which two plates slip past one another horizontally.
What is Pangaea
The single giant landmass that existed more than 200 million years ago and gave rise to the present-day continents
What is a transform fault.
A fault that runs across a midocean ridge.
What is seven.
There are _________ major lithospheric plates.
What is lithosphere.
The topmost solid part of the Earth, which is composed of the crust and some of the mantle.
What is a convection current.
A movement of material caused by differences in temperature.
What is continental drift.
The theory that the continents were once joined together and have since drifted apart.
What is magnetic stripes.
Scientists discovered that the history of the Earth's magnetism is recorded in _______________?
What is three.
There are __________ types of plate boundaries.
What is a plate.
In plate tectonics, one of the moving, irregularly shaped slabs that make up the Earth's lithosphere.
What is the pacific.
The largest lithospheric plate is the _________?
What is Glossopteris
These fossils are found in rocks 250 million years old and have been found in South Africa, Australia, India, and Antarctica, and they have seeds.
What is 9 times.
During the past 3.5 million years, the Earth's magnetic poles have reversed themselves __________ times.
What is older.
When two oceanic plates collide the _________ plate is subducted under the younger plate.
What is divergent boundaries.
A plate boundary at which plates move apart.
What is a strike-slip.
The San Andreas Fault is an example of a __________ boundary.