Geologic Time - Study Guide

Describe how geologists separate time periods.

• By special events that have happened in that period.

• By looking at the Relative Time of a Fossil

• By counting the years a fossil has been preserved

• By the animals in the time period.

How old do Paleontologists believe the Earth is?

• 2021 years old

• 4.6 million years old

• 4.6 billion years old

• 3.6 billion years old

Name the 4 time frames in order from oldest to youngest.

• Precambrian Time, Paleozoic Era, Mesozoic Era, Cenozoic Era

• Mesozoic Era, Precambrian time, Cenozoic Era, Paleozoic Era

• Paleozoic Era, Mesozoic Era, Precambrian Time, Cenozoic

The time span that lasted the longest was the...

• Precambrian

• Mesozoic

• Paleozoic

• Cenozoic

What are fossils that are abundant, easily recognizable, short lived, and widespread called?

• Preserved fossils

• Index fossils

• Imprints

• Radioactive dating

What does absolute age tell us about a rock layer or fossil?

• The 'exact' age of a fossil determined by radiometric dating

• The relative age of a fossil determined by radiometric dating

• Younger rock layers sit on top of older rock layers

• Older rock layers sit on top of younger rock layers

a model scientists use to describe the timing of events and the relationships between those events in earth’s history.

• geologic time scale

• era

• period

• epoch

Saying you are older than your sister is an example of _______.

• absolute age

• relative age

The end of life for a group of organisms, usually a species, is called a ___________.

• wipeout

• mass extinction

• meteorite

• dying off

What era did trilobites, fishes, and other marine organisms dominate?

• Precambrian

• Paleozoic

• Mesozoic

• Cenozoic