Download 5.06 - 1 - 5.06 Geologic Time Exposed Work File The Age of the

5.06
-15.06 Geologic Time Exposed Work File
The Age of the Earth
Resource Site 1:
1. What are two basic scientific reasons scientists cannot put an exact age
on the Earth? (One is discussed in this article; the other you should be
able to deduce with a little reasoning/thought.)
2. How old do many scientists believe the earth is?
3. How did scientists come up with the estimate for the age of the earth?
State two different lines of evidence that would support their estimate.
a.
b.
The Geologic Time Scale
At the resource site:
A. Read the introduction down to the 2).
B. Follow this link to “History of the Geologic Time Scale.”
C. Scroll down to “What do the divisions of the geologic time scale signify?”
4. Generally, what are the accepted divisions of geologic time? (Begin list
with largest division of time.)
___________, __________, __________, _________ and ________
D. Look at the diagram on this page showing geologic time divided into eons and
eras. Geologic time is divided into 2 eons, the Phanerozoic and the
Precambrian.
5. The Phanerozoic is the most recent and coincides with the appearance of
______________________________
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E. Go back to the “Exhibit Hall” page and click on Precambrian in the diagram.
6. The Precambrian Era is the earliest part of earth’s history and much of it is
not known, but we do know that some pretty important events occurred
during this time. What were they?
F. Go back to the “Exhibit Hall.” Work your way through the eras to complete the
next section.
7. What important events, both geological and biological were believed to
have occurred during each era? (We begin with the era in the most distant
past and work through to the most recent.)
a. Hadean
b. Archaean
c. Proterozoic
d. Paleozoic
e. Mesozoic
f. Cenozoic
G. On the Cenozoic page, scroll down find the link (in the text near bottom of
page) to the explanation on the Holocene epoch (They erroneously call it a
period in the text.)
8. From man’s perspective, what is significant about this epoch?
9. Climactically/environmentally what is significant about this epoch?