Lesson 2 Vocabulary: Relative Dating

Question 1

Relative Dating

Answer 1

Determining whether an object or event is older or younger than other objects or events.
Example: Once that know the order, a relative dating can be determined for each rock layer.

Question 2

Superposition:

Answer 2

Principle that states that younger rocks lie above older rocks if the layers have been disturbed.
Example: Superposition, is most likely found in the mountains, that contain fossils.

Question 3

Unconformity:

Answer 3

A break in the geologic record that is made when rock layers are eroded or when sediment is not deposited for a long period of time.
Example: A unconformity can happen between horizontal layers and layers that are tilted or folded.

Question 4

Fossils:

Answer 4

The traces or remains of an organism that lived long ago, most commonly preserved in sedimentary rock.
Example: A scientist found a fossil in South American, that has never been discovered.

Question 5

Geologic column:

Answer 5

An ordered arrangement of rock layers that is bases on the relative ages of the rock, with the oldest rocks at the column.
Example: A geologic column represents an ideal image of a rock layer sequence that doesn’t actually exist in any one place on Earth.

Question 6

What slow process would most likely form a mountain valley?

Answer 6

The process of glacial erosion, which is the gradual wearing away of Earths surfaces through the action of wind and water. They form steep valleys, just like the Grand Canyons.

Question 7

How could a geologist best date a a canyon, if he has the age of one rock?

Answer 7

Relative dating and absolute age determinations.

Question 8

How would a geologist find the age of the oldest layer of rock in a lake bed?

Answer 8

By using superposition, they can find the age of the oldest lake bed. Date the up youngest layer and move down.