Name: _________________________________
Edible Sedimentary Rocks
_________________________________
How do scientists use relative dating to determine the age of rocks and fossils?
Background
Until the advent of radiometric dating, scientists had no accurate method to determine the age of
rocks. For centuries scientist had to use observational skills to decipher the geological structures
they found. The method was termed relative dating, which is a method of sequencing events in
the order which they happened. Nicholas Steno formulated some principles to assist with
unveiling the age of geological structures. First, the law of superposition states that in an
undeformed sequence of sedimentary rocks, each bed is older than the one above it and younger
than the one below. Second, the principle of original horizontality states that most layers of
sediment are deposited in a horizontal position. Third, the principle of lateral continuity that
states the sedimentary layer will continue to spread until something prevents them from
spreading further. Several other scientists contributed to the field of geology by formulating
other principles such as faunal succession, inclusions and cross-cutting relationships. In this
investigation, we will use our knowledge of relative dating to determine the age of the rocks that
we create using edible items to simulate the formation of sedimentary rock with fossils.
Fossil
Swedish fish
Gummy bears
Time
444-416 mya
542 – 488 mya
Materials:
 Clear cups
 Spoons
 Zip lock bags
Procedure:



Chocolate pudding
Oreo cookies
Graham crackers



Gummy bears
M&Ms
Swedish fish
1. Smash the Oreos into small pieces. Be careful to not puncture the bag.
2. Smash the graham crackers into a fine powder. Again, be careful to not puncture the bag.
3. In the bottom of the cup dump half of the crushed graham crackers.
4. The second layer should be a medium size scoop of pudding. Add 2 gummy bears and a
3 M&Ms to the pudding. Smooth the pudding out over the bears and M&Ms.
5.
The third layer should be a thin layer of Oreo cookie pieces (approximately half of the bag).
6. Add another scoop of pudding. Mix in 3 M&Ms.
7. Sprinkle the remaining crushed graham crackers.
8. One more scoop of pudding. Add a couple of Swedish fish and top with the remaining smashed
Oreos.
9. DO NOT eat until you have completed your picture!
Results:
Draw a picture of your layers of rock. Label each layer. Based on the fossils found in the layers, assign
an age to the layer. Use the table above.
Layers of rock
Age of rock
Conclusion:
1. What is relative dating? _________________________________________________________
_____________________________________________________________________________
2. What is the principle of superposition? _____________________________________________
_____________________________________________________________________________
3. Who is credited with the idea known as the principle of superposition?
____________________________________________________________________________
4. Using the principle of superposition, explain how you know that the graham crackers are older than
the Oreos? ____________________________________________________________________
5. How old are the M&Ms? ________________ How do you know? ________________________
______________________________________________________________________________
6. Since gummy bears did not exist before 542 million years ago, what can you say about the rock
below it? _______________________________________________________________________
7. What must have happened to the gummy bears? _____________________________ How do you
know? _________________________________________________________________________
8. What kind of fossils are the gummy bears and Swedish fish? ______________________________
9. Write a paragraph the explains the similarities and differences between relative dating and
radiometric dating.
________________________________________________________________________________
________________________________________________________________________________
________________________________________________________________________________
________________________________________________________________________________
________________________________________________________________________________
________________________________________________________________________________
________________________________________________________________________________
________________________________________________________________________________
________________________________________________________________________________
________________________________________________________________________________
________________________________________________________________________________
________________________________________________________________________________
________________________________________________________________________________
________________________________________________________________________________
________________________________________________________________________________
________________________________________________________________________________
________________________________________________________________________________
10. Write a paragraph that explains how this activity relates to the material you are learning in science.
Be specific.
________________________________________________________________________________
________________________________________________________________________________
________________________________________________________________________________
________________________________________________________________________________
________________________________________________________________________________
________________________________________________________________________________
________________________________________________________________________________
________________________________________________________________________________
________________________________________________________________________________
________________________________________________________________________________
________________________________________________________________________________
________________________________________________________________________________
________________________________________________________________________________
________________________________________________________________________________
________________________________________________________________________________
________________________________________________________________________________
________________________________________________________________________________
________________________________________________________________________________
Needed
1
2
3
4
5
6
7
8
9
Instant pudding
chocolate
Instant pudding
chocolate
Instant pudding
chocolate
Instant pudding
chocolate
Instant pudding
vanilla
Instant pudding
chocolate
Instant pudding
chocolate
Instant pudding
vanilla
Instant pudding
vanilla
Quantity
1
1
1
1
1
1
1
1
1
10
Clear cups
36
11
Spoons
36
12
Swedish fish
1
13
Swedish fish
1
12
Oreos
1
13
Graham crackers
1
14
16
Ziplock 34 baggies
(snack or sandwich size)
Ziplock 34 baggies
(snack or sandwich size)
Gummy bears
17
Gummy bears
1
18
M&M
1
19
M& M
1
20
M&M
1
21
½ gallon of milk
1
22
½ gallon of milk
1
23
½ gallon of milk
1
15
1
1
1
Student