Law of Superposition

What does the Law of Superposition help scientists determine about rock layers?

• Their color and texture.

• Their chemical composition.

• Their relative age.

• Their exact depth underground.

Why are rock layers typically laid down in a flat, horizontal manner?

• Because of strong winds.

• Due to the Earth's rotation.

• Because gravity pulls materials downwards.

• As a result of volcanic eruptions.

If rock layers are broken and one side is lifted up, what geological event has occurred?

• Erosion

• A fault

• An intrusion

• Horizontal deposition

How can geologists determine that an igneous intrusion (molten rock moving up) is younger than the rock layers it cuts through?

• The intrusion is always a different color.

• The intrusion must have formed after the layers it cuts across.

• The intrusion is found at the very bottom of the rock layers.

• The intrusion is always made of a harder material.