1. OBJECTIVE: Create the geologic timeline.
54 January 2012 5
OBJECTIVE: Create the geologic timeline.
INTRO
When did Humans first evolve? When did dinosaurs roam? When did dinosaurs become extinct? When did life first appear? When did the Earth form?

2. Geologic Timeline

3. Geologic Timeline Geologic time scale How is it divided?
The standard method used to divide the Earth’s long natural history into manageable parts
Major increase or decrease (extinction) of life helps scientists divide Earth’s geologic history

4. Geologic Timeline Eon Era Largest division of geologic time
4 eons:
Hadean
Archean
Proterozoic
Phanerozoic
Smaller subdivisions of an eon

5. Geologic Timeline
Period
Smaller subdivision’s of an eon.

6. Geologic Timeline Hadean Eon 4.57 – 3.8 BYA No life
Earth’s crust cools and solidifies
Moon forms
Came from Greek word for “Hades” which mean’s “Underworld”
Earth had no liquid water and was covered with many active volcanoes.

7. Geologic Timeline Archeon Eon 3.8 – 2.5 BYA
First life is bacteria that forms in the ocean 3.5BYA
Atmosphere mostly methane and ammonia
Continents beginning to form
Greek word for “earlier life”

8. Geologic Timeline Proterozoic Eon 2.5 BYA – 543 MYA
First multi-cell life appears
Sponges
First complex life is algae appears 1.4BYA
Oxygen begins to fill atmosphere
Greek for “Origin”

9. Geologic Timeline Phanerozoic Eon 543MYA – Present
Divided into 3 Era’s
Paleozoic Era
Mesozoic Era
Cenozoic Era
Most recent eon that is we are in right now

10. Geologic Timeline Paleozoic Era 540 – 251 MYA Divided into 6 period’s
Fish first appear in oceans.
Greek word for “Ancient Life”
First animals evolve in ocean and then land

11. Geologic Timeline
Plants are first life on land and begin to create first forests and an oxygen-rich atmosphere
First animals appear on land: insects, amphibians, and reptiles
Amphibians dominate the land
Period ends with largest mass extinction ever
95% marine life die
50% of all animals die

12. Geologic Timeline Mesozoic Era 251 – 65 MYA “Age of Dinosaurs”
Divided into 3 periods:
Triassic Period
Jurassic Period
Cretaceous Period
Mammals, dinosaurs, and crocodiles appear
Dinosaur’s dominate the land
Period ends with extinction of dinosaurs

13. Geologic Timeline Cenozoic Era 65 MYA – Present
Greek word for “ New Life”
“Age of Mammals”
Divided into 2 periods
Paleogene Period
Neogene Period (we are in this one now)
Rise of mammals
Neogene period begins with the first humans appearing 23,000 years ago
By the end of the period, modern humans appear and develop civilization

14. OBJECTIVE: Create the geologic timeline.
54 January 2012 5
OBJECTIVE: Create the geologic timeline.
OUTRO
List 3 things you never knew about Earth’s geologic history before making this timeline?