Download Geologic Time Activity - Cloverleaf Local Schools

Geologic Time Activity
Compare geologic time to the length of a football field, which is 100 yards long.
Earth formed about 4.6 billion years ago. That's 4,600,000,000! If you divided 4.6
billion by 100, then each yard equals 46,000,000 years, and each ten yard
section equals 460,000,000 years.
Making a Time Line
Draw a model of a football field. Starting at the left (4.6 billion years ago) and
"moving forward in time," label the 10-yard lines in years. Then, using different
colored markers, draw a horizontal line to show the beginning and end of each of
the following periods and eras.
1. Cenozoic Era (65 million years ago [mya] to present)
2. Triassic (245-208 mya), Jurassic (208-146 mya), and Cretaceous (146-65
mya) periods
3. Paleozoic Era (570-245 mya)
4. Proterozoic Era (2500-570 mya)
5. Archaean Era (3800-2500 mya)
6. Hadean Era (4600-3800 mya)
Add the historic and prehistoric events from your list that you made at the
beginning of the class. Also add at least ten other important events in geologic
history. Use the back of the page and books from my cupboard to help you find
the dates for them.
Challenge: Make a circle, pie diagram, or clock that shows the amount of time in
degrees (there are 360 degrees in a circle) or in percentages for the following:
1. a clock of the 4.6 billion year history
2. a clock of the Mesozoic (Triassic, Jurassic, and Cretaceous)
3. a clock of the Mesozoic to the present.
Some Important Dates (subject to revison!) in the History of the Earth:
Millions of
Event
Years Ago
4600
Origin of the Earth
3900
Oldest Dated Crustal Rocks
3800
Oldest Evidence for Life
2000
First Oxygen Atmosphere/Ozone Layer Forms
900
Oldest Metazoan Fossils
510
Oldest Fossil Fish
458
First Land Plants
440
Bedrock in Oxford Forms/Ohio near the equator
375
That important first step: Amphibians Evolve
245
Huge Mass Extinction at End of Permian Period/
Close of the Paleozoic Era
200
First Mammals
160
First Birds
145
Atlantic Ocean first opens
130
Angiosperms (Flowering Plants) on the Scene
65
Adaptive Radiation of Mammals/Dinosaurs Go Extinct/
Close of the Mesozoic Era/Beginning of the Cenozoic Era
3.4
New discoveries of (LUCY)Australopithecus afarensis fossils from
Ethiopia--Males and females show sexual dimorphism
2
Pleistocene Ice Age begins/Light from the Andromeda galaxy seen today
left Andromeda 2 x 106 years ago!
.600
Age of Homo erectus fossils from Ethiopia
.125
Oldest rocks in the Bahamas
.100
Homo sapiens appears in the fossil record
.015
Last ice sheet retreats from Ohio
.007
Grahams Harbor, San Salvador, Bahamas floods due to rising sea level
after Ice sheets are reduced to modern day volume
.000503
Columbus lands in New World
??
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