Discovering the Age and History of Earth

Which is the most accurate method used in determining the true age of a fossil?

• relative dating

• fossil record

• radioactive dating

• law of superposition

Which best describes the relationship between rock layers and index fossils?

• Different rock layers contain only specific species.

• Different rock layers are compared to find the exact age.

• All layers w/ the same fossils are the same age.

• Layers have same relative age if they have same index fossils

Which best describes a fossil that helps determine the relative age of a rock layer?

• trace fossil

• Mold fossil

• index fossil

• intrusive fossil

Which type of radioactive dating would be most useful in determining the age of fossil 40,000 years old or younger?

• C-14 method

• U-238 method

• K-Ar method

• None

Which layer is considered the youngest?

• A

• C

• E

• D

Which method can best be used by the students to determine the relative age of these layers?

• Law of superposition

• Uniformitarianism

• Carbon-14 dating

• Radioactive dating

Which is the best predictor of the relative age of a layer of rock?

• thickness of layer

• length of layer

• position of layer

• size of layer

Index fossil are found in layers of rock in Africa & South America. What are the fossil ages?

• The African rock is older.

• The South American rock is older.

• The rocks are younger than the fossils.

• The rocks are approximately the same age.

Which inference can be made about the relative age of a fossil found in a sedimentary rock bed?

• The fossil formed around the time of rocks in the same layer

• The fossil & the rock were formed in different environments

• The fossil was formed before the rock layer that contains it

• The fossil is younger than the rock layer above it

Why are index fossils used as guides to determine the age of rocks?

• Each index fossil lived in a specific geologic time period

• All index fossils lived at all the periods of geologic time

• Index fossils are rare and are not commonly found in rocks.