Download 13.1 Precambrian Time Precambrian Earth

13.1 Precambrian Time
Name _________________________________
Date ______________
Test your prior knowledge:
1. The law of superposition states that if rock layers have not been overturned, the oldest rock
layers are found on the ________________ .
2. What do trees require to perform photosynthesis?
3. What mechanism is moving Earth’s plates?
4. What three ways can seeds be carried away from the parent plant?
5. What would you be likely to find in an arid climate?
a. many swamps
c. large forests
b. vast desert
Precambrian Earth
Earth formed about ____________ billion years ago. During Precambrian time, the
______________________ and ___________________ formed and _______________ tectonics began
to build up continental land masses.
Earth’s original atmosphere was made up of gases similar to those released in volcanic eruptions --___________________________ , ______________________ , nitrogen, and several trace gases but no
___________________ .
Earth’s earliest life forms used carbon dioxide and released oxygen into the atmosphere. As the oxygen
accumulated, it reacted with ________________ to form rust. Once the available _____________
finished reacting, oxygen began to accumulate in the atmosphere.
As Earth continued to cool, _______________________ condensed to form clouds, and torrential
______________ began. Torrential ______________ continued and slowly filled ________ areas,
forming the oceans.
The creation of the ocean reduced the gases in the atmosphere by _______________ them. With a
reduction of _________ and _________________ in the atmosphere, a _______________ - rich
atmosphere remained.
Geologists think that small continents began to form about _________ million years after____________
formation. At the same time, the rock cycle began. Early continents were made up of _______________
igneous rock.
Weathering and erosion led to the formation of ______________________ rocks. Tectonic forces and
__________________ activity in the crust helped to form _______________________ rocks.
As you would expect from the Law of ______________________, most Precambrian rocks are buried
under more recent rock. But Precambrian rocks are __________________ where younger rock layers
are extensively ____________________ . Precambrian rocks exposed at the surface are called
________________ because they resemble a warrior’s shield. Much of what we know about
Precambrian rocks comes from _____________ mined from __________________.
Geologic Timeline Foldable
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Take a sheet of notebook paper and fold it hot dog style.
Next fold the paper in half twice (see figure below)
When you open the paper, it should be divided into four (4) equal sections.
Cut the edge of the paper containing the binder holes off.
Cut each individual flap.
Below each flap, write the name of the Era. (i.e. Precambrian, Paleozoic, Mesozoic, and
Cenozoic)
7. At the bottom of each flap, write the starting date of each era respectively.
8. Open the flap.
9. At the top of the flap. List significant geological events that occurred for each era
respectively.
10. At the bottom of the flap, List significant life forms that existed for each era respectively.
11. Finally, you are going to draw pictures of the life forms on the front of the flap.
12. You must include atleast two life forms per era.
13. You may use the following website or a textbook to help with your research.
http://www.ucmp.berkeley.edu/exhibits/historyoflife.php
1. Notebook Paper
3. Fold in half
2. Fold hot dog style
4. Fold in half again
5. Four equal panels