The document discusses geologic principles for understanding the Earth's history. Students are asked to brainstorm how these principles are like a layer cake. The principles discussed are uniformitarianism, superposition, original horizontality, and catastrophism. For each principle, students come up with a simile comparing it to a layer cake and illustrate it. They then answer the evocative question of how the geologic principles are like a layer cake by brainstorming as a group.

1. Evocative Question (Page 28)
How are the
geologic
principles for
understandin
g the Earth’s
history like a
layer cake?

2. Brainstorm
Brainstorm with your
group the answer the
evocative question on
page 28 in your
notebook.

3. Foldable:
Uniformitarianism
Superposition
Original
Horizontality
Catastrophism

4. Inside:
 Look in pages 152-156 in your
textbook.
 Find the explanation for each of the
geologic principles. (Original
Horizontality is not in the book)
 Write it on the notebook part of the
inside of your foldable.
 You have 7 minutes to find the
information, and then we will

5. Uniformitarianism
 The geologic processes that happen today
(mountain building, volcanoes, rocks)
happened the same way in the past AND
change on the Earth is occurring slowly and
constantly.
 Brainstorm a simile about cake for the
Principle of Uniformitarianism with your group.
Write it in your foldable. The Principle of
Uniformitarianism is like…

6. Superposition
 In horizontal sedimentary rock layers, the
oldest layer is at the bottom. Each higher layer
is younger than the layers below it.
 Brainstorm a simile about cake for the
Principle of Superposition with your group.
Write it in your foldable. The Principle of
Superposition is like…

7. Original Horizontality
Sediment settles out of water
in horizontal layers. Larger
sediment settles first and smaller
sediment settles later. Sedimentary
rocks form in horizontal layers.
 Brainstorm a simile about cake for the
Principle of Original Horizontality with your
group. Write it in your foldable. The Principle
of Original Horizontality is like…

8. Catastrophism
 Geologic Change occurs suddenly
 Brainstorm a simile about cake for the
Principle of Catastrophism with your group.
Write it in your foldable. The Principle of
Catastrophism is like…
http://www.flickr.com/photos/sylvia/5727154433/sizes/m/in/photostream/http://www.flickr.com/photos/sanfranannie/3639238588/sizes/m/in/photostream/

9. Evocative Question
Brainstorm with your group
and come up with a final
answer to the evocative
question.

10. Write Your Own
Now, on your own, write
one simile on page 29 for
each of the geologic
principles.
With your simile, draw a
picture that illustrates it.