Plate Motion Unit Review

Front

Who proposed the Theory of Continental Drift?

Back

Alfred Wegener

Answer explanation

The Theory of Continental Drift was proposed by Alfred Wegener in 1912. He suggested that continents were once joined and have since drifted apart, a concept that laid the groundwork for modern plate tectonics.

Front

The idea that the continents were once a large supercontinent that separated over time is...

Back

Theory of Continental Drift

Answer explanation

The Theory of Continental Drift posits that continents were once joined as a supercontinent and have drifted apart over time. This concept is distinct from the Theory of Plate Tectonics, which explains the mechanisms behind this movement.

Front

What is the name of Wegener's supercontinent?

Back

Pangaea

Answer explanation

Wegener's supercontinent is called Pangaea. It existed during the late Paleozoic and early Mesozoic eras, bringing together all the Earth's landmasses into one large landmass before they drifted apart.

Front

The Theory of Plate Tectonics claims the plates are...

Back

In constant, slow motion.

Answer explanation

The Theory of Plate Tectonics states that tectonic plates are in constant, slow motion due to convection currents in the Earth's mantle, which allows them to move gradually over time.

Front

What type of plate boundary is formed when plates slide past each other in opposite directions?

Back

Transform

Answer explanation

A transform boundary occurs when tectonic plates slide past each other horizontally. This movement can cause earthquakes along faults, distinguishing it from convergent (plates collide) and divergent (plates move apart) boundaries.

Front

A convergent boundary is formed when two plates...

Back

Collide

Answer explanation

A convergent boundary is formed when two tectonic plates collide. This interaction can lead to one plate being forced under another, resulting in geological features like mountains or trenches.

Front

A rift valley is typically found when plates separate, which is the boundary known as...

Back

Divergent

Answer explanation

A rift valley forms when tectonic plates separate, which occurs at divergent boundaries. This is where new crust is created as the plates move apart, making 'Divergent' the correct answer.

Front

Who proposed the Theory of Sea-floor Spreading?

Back

Harry Hess

Answer explanation

The Theory of Sea-floor Spreading was proposed by Harry Hess in the early 1960s. He suggested that new oceanic crust forms at mid-ocean ridges and spreads outward, a key concept in plate tectonics.

Front

The process that continually adds new material to the ocean floor is...
Options: Sea-floor spreading, Continental Drift, Plate Tectonics, None of the above

Back

Sea-floor spreading

Answer explanation

Sea-floor spreading is the process where new oceanic crust is formed at mid-ocean ridges and gradually moves away, adding material to the ocean floor. This distinguishes it from continental drift and plate tectonics.

Front

The closer you are to the mid-ocean ridge, the ___________ the rock is. The farther you are from the mid-ocean ridge, the __________ the rock is.

Back

Younger and hotter, Older and cooler

Answer explanation

The mid-ocean ridge is where new rock forms, making it younger and hotter. As you move away from the ridge, the rock cools and becomes older, hence the correct choice is 'Younger and hotter, Older and cooler'.