Geologic Time

The age of a rock given as the number of years since the rock formed.

• relative age
• half-life
• absolute age
• radioactive decay

The age of a rock compared to the ages of other rocks.

• relative age
• half-life
• absolute age
• radioactive decay

A record of the geologic events and life forms in Earth's history.

• index fossil
• half-life
• radioactive dating
• geologic time scale

Fossils of widely distributed organisms that lived during a geologically short period.

• index fossil
• half-life
• radioactive dating
• geologic time scale

Which of the following represents the longest time period

• Precambrian
• Paleozoic
• Mesozoic
• Cenozoic

The _________ was an era dominated by the dinosaurs

• Precambrian
• Paleozoic
• Mesozoic
• Cenozoic

Identify the Era:
called the "Age of Mammals"

• Precambrian
• Paleozoic
• Mesozoic
• Cenozoic

Identify the Era:
First forms of life appeared in this era.

• Precambrian
• Paleozoic
• Mesozoic
• Cenozoic

Which is closest to the accepted age of the Earth?

• 4,000
• 4 million 
• 4 billion 
• 4 trillion

Which layer is the oldest?

• A
• B
• C
• D