The Geologic Time Scale

Scientists chose where units of geologic time end and begin based on

• the color of rocks
• Major changes in biology of fossils

• random geological formations

Tags

NGSS.MS-ESS1-4

NGSS.MS-LS4-1

Each era is made up of multiple

• periods
• phases
• stages

Tags

NGSS.MS-ESS1-4

The time since the precambrian is broken up into 3

• Periods

• Eons

• Eras

Tags

NGSS.MS-ESS1-4

Because the time span of Earth's history is so great, geologists use the ___________________time scale to show Earth's history.

• geological
• astronomical
• historical
• chronological

Tags

NGSS.MS-ESS1-4

This section of time makes up 88% of Earth's history where we have only single celled organisms and little fossil evidence.

• Paleozoic
• Mesozoic
• Cenozoic
• Precambrian

Which is NOT an era of Earth's history

• Paleozoic

• Cenozoic

• Neozoic
• Mesozoic

Tags

NGSS.MS-ESS1-4