Chapter 7 Review

When the Earth's crust slowly springs back to its original elevation:

Which type of plate boundary moves apart?

Which type of Boundary is this?

How much of the Earth's mass is made up by the core?

The three main elements that make up the Earth's crust are oxygen, silicon, and aluminum.

What do scientist use to study Earth's interior?

The process of forming new oceanic lithosphere as magma rises to the surface is called...

Which layer of the earth's core is solid?

What element makes up the core?

A downward troughlike fold

What is the bending of rock layers due to stress?

Sea floor spreading begins at -

A strike-slip fault is created from what type of plate boundary?

Beneath the lithosphere in the mantle is a softer, weaker layer of rock that flows slowly

The mantle has less aluminum and less silicon than the crust does.

What did Wegener hypothesize happened to the continents?

Process that happens when Earth's magnetic poles change place

Boundary at which two tectonic plates separate

A fold where both ends of the rock layer are horizontal

A set of deep cracks that forms between two tectonic plates that are pulling away from each other

What Is Sea-Floor Spreading?

What three types of evidence did Wegner find to support his theory?

The rising of the Earth's crust to higher elevations:

What is the liquid layer of the Earth's core?

What hypothesis by Alfred Wegner explain why continents seen to fit together?

When tectonic plates collide, folds and faults can become

When stress squeezes an object it is called

The Earth is composed of several ___________

An upward-arching fold in a rock layer

The oceanic crust contains more iron, calcium and magnesium which casue it to be less dense than the continental crust

What kind of mountain range is formed when rock layers are squeezed and forced upward?

What is the amount of force placed on a given material called?

Strong rigid lower part of the mantle

According to Wegner, how many landmasses did all continenets once form?

Scientist look at the ocean floor because magma from the mantle flows out of active volcanoes on the ocean floor.

The cold and rigid outermost layer of Earth.

Theory that explains how continents reached their current locations

A Substance Composed of Two or More Elements

Why did scientists reject Wegner's theory?

The place where tectonic plates touch is known as the

This is the theory that the Earth is divided into plates that move.

Heavier elemets are pulled to the center of the Earth by gravity. Elements with less matter are futher from the center.

Fossil evidence supports Wegner's theory of continential drift.

Tectonic plates are NOT like the pieces of a jigsaw puzzle because they do not fit together

Most tectonic plates have two kinds of crust, what are they?

What kind of mountain is formed when magma rises to the surface and erupts?

What are the three layers of Earth?

What are seismic waves?

The single land mass that split into two huge landmasses called Gondwana and _____________ about 180 million years ago.

Rock on the ocean floor provided the final proof of sea-floor spreading with a record of _____>

Which type of boundary is this?

Plates can move in three main ways

Which type of plate is subducting?

This is a stress that stretches or pulls rocks apart.

The sinking of regions of the Earth's crust to lower elevations:

The mantle is composed of more of the element magnesium than the crust.

Wegner thought that all of the present continents were once joined in a single landmass called

Boundary at which two tectonic plates collide

Large pieces of lithosphere that move around on the asthenosphere are called

The process by which the shape of a rock changes because of stress is called?

What type of boundary occurs when two plates slide past each other?