Geologic Time Scale

What is an index fossil?

• A fossil that is useful for dating and correlating the strata in which it is found.

• A fossil that has been recorded in the index of geology reference guides.

• A fossil that is long-lived, widespread, and abundant.

• A fossil that is useful in correlating skeletal structures of earlier life forms.

Which rock strata is the youngest?

• A

• B

• C

• D

• E

Which rock strata is the oldest?

• A

• B

• C

• D

• E

Which relative rock dating law(s) are shown in the image?

• Law of superposition only.

• Law of superposition and crosscutting.

• Law of inclusion and superposition.

• Law of inclusion only.

Putting laundry in the basket over time best illustrates which rocking dating law?

• Radioactive dating.

• Law of superposition.

• Law of crosscutting.

• Law of inclusion.

What is the principle that states Earth's processes occurring today are similar to those that occurred in the past?

• Index fossils

• Unconformities

• Uniformitaianism

• Superposition

Relative rock dating...

• compares the age of surrounding rock layers.

• uses radioactive dating methods.

• uses the law of crosscutting only.

• is not always reliable.

What is an unfonformity in rock strata?

• a missing interval in the strata record.

• an interruption in rock strata by weather and erosion.

• an interruption in rock strata by earthquakes or magma.

• All of the above.

Dinosaurs and early human ancestors coexisted at one time.

• True

• False

What determines when an era begins and ends?

• Mass extinction.

• Every 1 billion years.

• The distance between index fossils.

• The rise of oxygen.