Name:_______________________________________________________
Yummy Plate Tectonics!
Theory of Plate tectonics- Background Information
The theory of plate tectonics states that the
lithosphere is made up of plates that move. This theory
also explains why and how earthquakes and volcanoes are
likely to occur within certain areas as well as how new
crust forms along the ocean floor. These plates are thought
to float across the top of the asthenosphere. The
asthenosphere is the layer just below the lithosphere.
While in motion the plates interact with each other at their
boundaries. The interactions at the boundaries of the
plates, refers to how the plates interact at their edges.
Plates interact with one in other in several ways. The main
types of interactions are convergent, divergent and
transform boundaries. Use Oreos for to demonstrate a
sliding plate over the asthenosphere and the following types of boundaries.
Transform boundaries are when two plates slide past one another. With transform boundaries the movement of the
plates is not equal. An example of a transform boundary is in California. This occurs where the North American plate
passes along the Pacific Plate, along the San Andreas Fault. During this movement the Pacific Plate is moving Northwest
and the North American Plates is moving southwest. Portions of the San Andreas Fault move as much as five centimeters
per year, whereas in other sections it has not moved in over a century.
When two lithospheric plates move away from each other they are considered to be a divergent boundary. Divergent
boundaries sometimes referred to as “spreading centers,” occur during sea-floor spreading. An example would include
the Mid-Atlantic Ridge.
With convergent plate boundaries the plates are moving toward each other or converging. There are two types of
convergent plate boundaries: subduction and collision boundaries. Subduction boundaries occur when an oceanic plate
goes beneath another plate (subducting). These can occur when two oceanic plates or when an oceanic plate and a
continental plate converge. When two oceanic plates converge they form a deep-sea trench, which followed by the
formation of a chain of volcanic islands. Example includes the Mariana Trench that has created the volcanic Mariana
Islands.
When oceanic plates converge with continental plates the denser oceanic plate subducts beneath the continental plate.
A deep sea trench is formed, and then a mountain chain and volcano may form.
Collision boundaries are also considered convergent boundaries. These boundaries occur when two converging plates
carry continents. These two continents generally become glued together, creating one larger continent. This collision
generally will cause one plate to be pushed upward into a mountain range. An example of such an event created the
Himalaya Mountains.
Materials:
CLEAN Petri dish
New disposable eyedropper
2 Oreos (1 vanilla, 1 chocolate)
One cup of milk of choice
Toothpick
paper towels
Part I:
1. Carefully, without breaking the cookie, twist off and remove the cap of the chocolate Oreo cookie.
2. Lay your chocolate cookie cap on the paper towel. Using your toothpick, slowly and carefully “drill-out” a hole in
the center of you chocolate Oreo by rotating your toothpick into the center of your cookie. Press lightly and try
not to break your cookie. If you do break your cookie, try again using the bottom of your chocolate cookie.
3. Next, lay down the paper towel under your cookie. Keep the paper towel directly under you as you complete the
following steps.
4. Next, “trap” 1mL of milk in the STEM of the eyedropper.
5. Now for the fun part! With the eyedropper UNDER your cookie, while working over the paper towel, squeeze
the milk upward through the hole of your cookie! Set the cookie pieces on the paper towel.
6. Record your observations in the Oreo Plate Tectonics Data Table and then answer the questions below.
a.
What type of geologic structure did you just model?
b. Describe the formation of this geologic structure.
c.
Provide an example of where we can find one of these on earth.
Part II:
1. Using a clean sponge, wash your petri dish with soap and water. Fill the petri dish with milk.
2. Now, break your chocolate cookie top in half. Then, remove the vanilla cookie top and break it carefully in half.
Soon you will be placing the cookie tops afloat on the milk. Knowing this, answering the following questions.
a. What do the cookies represent?
b. What does the milk represent?
c.
On the surface of the earth, what are the two types of crust? What is the main type of rocks in each
type?
d. Which color cookie represents which type of crust? How do you know? Use the composition of the
earth’s crust in your explanation.
e.
If this process were completely accurate, what would be happening to the chocolate cookie when the
two collided?
3. Now, place half of the vanilla cookie on the surface of the milk with the chocolate half. Then, slowly push them
together. Then, take the cookies pieces out of the milk and place them on the paper towel so that the cookies
pieces do not become over saturated.
4. Record your observations in the Oreo Plate Tectonics Data Table and then answer the questions below.
a. What is the type of boundary was demonstrated?
b. What is created along these types of plate boundaries?
c. Provide TWO real-world examples of landforms created from this type of plate boundary.
5. Now, place the two vanilla halves on the surface of the milk and push them together.
6. Record your observations in the Oreo Plate Tectonics Data Table and then answer the questions below.
a. What is the type of boundary was demonstrated?
b. What is created along these types of plate boundaries?
c. Provide TWO real-world examples of landforms created from this type of plate boundary.
7. Now, place the two chocolate halves on the surface of the milk and push them together. Then, take the
cookies pieces out of the milk and place them on the paper towel so that the cookies pieces do not become over
saturated.
8. Record your observations in the Oreo Plate Tectonics Data Table and then answer the questions below.
a. What is the type of boundary was demonstrated?
b. What is created along these types of plate boundaries?
c. Provide TWO real-world examples of landforms created from this type of plate boundary.
Part III:
1.
Now place the two chocolate halves on the surface of the milk. Start with the pieces touching then slowly push
the apart. Then, take the cookies pieces out of the milk and place them on the paper towel so that the cookies
pieces do not become over saturated.
2. Record your observations in the Oreo Plate Tectonics Data Table and then answer the questions below.
a. What is the type of boundary was demonstrated?
b. What is created along these types of plate boundaries?
c. What is the name of the landform where these plate boundaries occur? (hint: large mountains)
d. Why were the chocolate cookies halves used instead of the vanilla?
e. Provide a location where we can observe this in the ocean? Land?
Part IV:
1. Lastly, place the vanilla half and the chocolate half next to each other so that they are touching. Now, slide each
half past each other in two different directions. Then, take the cookies pieces out of the milk and place them on
the paper towel so that the cookies pieces do not become over saturated.
2. Record your observations in the Oreo Plate Tectonics Data Table and then answer the questions below.
a.
What type of plate boundary did you model?
b. Where can we find a real-world example of this type of plate boundary?
c.
Based on the example you listed above, why were both vanilla and a chocolate cookie used? Explain.
Oreo Plate Tectonics Data***Keep in mind that Continental crust is EXTREMELY thick in comparison to oceanic crust and looks more
like an iceberg as it sits into the mantle. While oceanic crust is extremely thin and flat, yet denser due to its
basaltic iron content.
Activity
#1 Sliding Plate
over
Asthenosphere
(Hot Spots)
Drawing of Oreo construction:
Drawing of real-world formation with
labeled plate boundaries
#2 Convergent:
Type?
_______________
Convergent:
Type?
______________
Convergent:
Type?
_______________
#3 Divergent
#4 Transform
Analysis and Conclusion Questions:
1.
Provide a diagram as to the formation of Hawaii (Hot spot) versus the formation of Mt. Saint Helens (O-C
Convergent). Drawn and label the diagrams demonstrating the types of crust involve, any subduction zone and
use arrows to show the motion of the crust.
2.
What are the main elements that make-up our continental crust?
3.
What the elements that make-up oceanic crust?
4.
Which type of plate boundary would results in an Orogeny? Provide TWO real-world examples. Then, draw and
LABEL a diagram to show how they are formed.
5.
Identify each picture’s plate boundaries:
a._______________________________
b. ______________________________
c. __________________________
6.
Compare and contrast the consistency of the Asthenosphere versus the Lithosphere. How do you predict
the difference in consistency places a role in the motion of the plates?
7.
What is subduction and why is it important? What causes subduction? Explain.
8.
Examine the Atlantic versus the Pacific Ocean floors. Based on the plate boundaries that are present within
each ocean, complete the data table below:
Ocean:
Type of
Boundary:
Draw ocean floor for each area:
How similar:
How different: