1. Table of Contents
Title: Geologic Time
Page #: 14
Date: 11/14/2013

2. Objective
Students will be able to explain the Geologic eons and eras.

3. Words of the Day Eon: The longest division of geologic time
Era: A distinctive period of time.

4. Geologic Time
Geologic Time - Used to refer to events in the history and formation of the earth.
4 Main divisions called “eons”:
Hadean: 4.6 to 4 Billion years ago.
Archaen: 4 Billion to 2.5 Billion years ago
Proterozoic: 2.5 Billion to 570 Million years ago
Phanerozoic: 570 Million years ago to now

5. Geologic Time
Hadean, Archaen, Proterozoic are called the Precambrian Era: makes up 88% of geologic time.
Phanerozoic - is the eon where fossils are found.
Phanerozoic is divided into 3 eras:
Paleozoic era - “ancient life”
Mesozoic era - “middle life”
Cenozoic era - “recent life”
Fossil Record

6. Make sure
You have
This print
Out.

7. Geologic Time Geologic time is so big that it is hard to understand.
Earth is 4.6 Billion years old
Vertebrates - animals with a spinal column first appeared 500 million years ago.
What does that mean?