Geologic History and Dating Unit

Which set of characteristics produces a good index fossil?

• narrow time frame, wide geographic region

• wide time frame, narrow geographic region

• narrow time frame, narrow geographic region

Which letter best represents an index fossil?

• W

• X

• Y

• Z

Which group of index fossils includes Bothriolepis?

• Trilobites

• Graptolites

• Corals

• Placoderm Fish

When did a mass extinction of dinosaurs and many land plants occur?

• 65.5 mya

• 251 mya

• 300 mya

• 440 mya

Which group of organisms is still in existence today?

• Graptolites

• Crinoids

• Eurypterids

• Trilobites

Which scientific principal states that younger rock layers are generally deposited on top of older rock layers?

• Superposition

• Evolution

• Original Horizontality

• Inclusion

Jurassic and Ordovician are examples of geologic ______________.

• eons

• epochs

• eras

• periods

The matching of rock outcrops or fossils exposed in one geographic region with those in another is __________________.

• Cross Cutting Relationships

• Correlation

• Disconformity

• Unconformity

A ____________________ is the amount of time it takes for half of a radioactive element to decay.

• Radiometric Dating

• Radiology

• Half Life

• Radiometric Halving

In order for an organism to be used as an index fossil, the organism must have been geographically widespread and must have

• lived on land
• lived in shallow water
• been preserved by volcanic ash
• existed for a geologically short time