FORMATION OF A FossIl
Jobs (Circle your name):
Reads directions:____________________________
Gathers materials:___________________________
Supplies to gather:
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Aluminum pie container 
8 oz cup cup

Popsicle stick
2 scoops of Sand
Mixes Plaster of Paris:________________________
Clean-up duty:______________________________
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Excavation tools

100 mL Plaster of Paris 
4 Toys or shells
70mL water
DAY 1:
Laying down a layer of sediment
1.
2.
3.
4.
Gather necessary materials.
One member of your group needs to dump 2 full cups of sand (8 oz Styrofoam cups) into the aluminum container.
If the sand is dry, add a small amount of water.
Smooth out the sand so that there are no bumps and the sand is level…use your popsicle stick.
Organism collapses and dies on top of your layer of sediment
5. Place your toy on top of the sand…apply a large amount of pressure to the top of the toy (be sure to push on all
edges) so that it makes a noticeable indentation in the sand. Don’t allow the toy to rotate.
Organism decays leaving behind an indentation…also known as a mold
6. Remove your toy from the sand.
Mold becomes filled with minerals and preserves the shape of the original organism
7. One group member needs to scoop 100mL of Plaster of Paris into the cup
8. Add 70mL of water and immediately begin to stir the mixture together.
9. Slowly pour the Plaster of Paris and water mixture into the indentations left by the toys. You need to make sure
that the entire indentation is filled in… the Plaster of Paris needs to fill more than simply the toy indentation.
Organism becomes buried by sediment…fossil is preserved
(This actually would have happened before the fossil decayed, not after)
10. One member of your group needs to obtain a full cup of sand.
11. Pour the sand over the top of your sand and Plaster of Paris mixture.
12. Smooth out the sand so that there are no bumps…use your popsicle stick. Be careful not to apply too much
pressure in any one particular location as this will ruin your Plaster of Paris mixture.
Sediment undergoes compaction and cementation to become a sedimentary rock
13. Place your circle cardboard cutout on top of your aluminum container.
14. Apply a small amount of pressure to the top of the circle cardboard cutout.
Fossil is left undisturbed for millions of years
15. Place your aluminum container somewhere in the classroom with a piece of paper underneath it containing your
group member’s names. Be careful not to allow your aluminum foil pan to bend as this will ruin your Plaster of
Paris mixture.
16. Let the mixture sit undisturbed until at least one day has passed.
17. Throw away the cup with the excess Plaster of Paris into the garbage located in the front of the class.
18. Rinse out your sand cups and return them to your teacher along with the circle cardboard cutout.
19. Clean up any mess that is around your work space…including sand on the floor.
DAY 2:
Finding sedimentary rock that contains fossils in it
1. Obtain your groups aluminum container.
Digging up the fossils and extracting it from the sedimentary rock
2. Each person should use a popsicle stick to dig out a Plaster of Paris fossil.
3. Use your excavation tools and water to remove sand from the Plaster of Paris fossil.
Using the fossils to learn more about the past
4.
5.
6.
7.
Study your fossil to see if you can recognize if it is your own specific Plaster of Paris fossil.
Dump your leftover sand in the container located at the front of the classroom.
Rinse off and return your aluminum container and popsicle stick to your teacher.
Take your fossil home to conduct more scientific research!
Name:______________________________________ Per:_____
FORMATION OF A FOSSIL Questions:
1. What is a fossil?
2. What types of fossils are considered Original remains?
3. In this lab, is the fossil that you excavated considered Original remains? Why or why not?
4. What has to happen to a fossil if we are going to be able to discover it millions of years later?
5. In this lab, which part of the fossil process was actually out of order?
6. If your fossil actually went through the process that the lab outlines, would the fossil survive for millions of
years? Why or why not?
7. Explain the entire process of how a fossil would form and be preserved for millions of years:
8. What type of rock are fossils found in?
9. What is a mold?
10. In this lab, what would be considered the mold?
11. What is a cast?
12. In this lab, what would be considered the cast?