Digging into the Past
Time: 40-60 minutes
Materials (per class)
1 container of white
sugar with sprinkles
Newspaper to cover
workspace
1 container of
brown sugar
Plastic spoons
1 container of
blue/green sugar
½ sheets of paper or
large index cards
1 container of
red/orange sugar
Colored pencils
Materials (per group of 2-3 students)
Small opaque cup, 150-200
mL (Dixie cups work well)
Clear plastic straw
4 clear cups
Additional/background information
Directions
1. A lot of things are made one layer at a time—birthday cakes, ice cream sundaes, and
brick walls are all examples. Another example is a peanut butter and jelly sandwich.
Ask students to list the layers of the sandwich, staring from the bottom:
1 – Bread
2 – Peanut butter
3 – Jelly
4 - Bread
2. Ask students which layer had to be put down first? This layer is the oldest, and it is
the base for all other layers.
3. Tell the students that the Earth has layers as well, only they are made up of rock.
Ask them if the layer we walk around on now is the oldest or the youngest. (It’s the
youngest.) Geologists use those layers to learn more about the Earth by drilling into
the ground and removing a column of rock. The layers in the column are important
because they tell the order in which things happened, and the fossils in the rocks
help the scientists estimate the age of each layer. This helps them understand the
Earth’s history.
4. Tell the students that today they will be geologists. First, they will create a
“geological history” in a cup using colored sugar. Then, another team of geologists
will take a core sample to determine how the layers were formed.
Part One: Making History
5. Instruct the students to form groups of two or
three. Have one person from each group come
up and get a spoon, the opaque cup, a half-sheet
of paper, a straw, and newspapers to cover their
work space.
6. Based on how the groups are set up, set out
clear cups filled with each sugar variety for
every group, or have two-three groups share.
7. On one side of their paper, students should create a plan for their geological history.
The different colors indicate different types of rocks, and the sprinkles are fossils.
Everyone should have brown sugar as their bottom layer. This makes the
straw work much better.
8. Once the plan is complete, students should spoon around 1 cm (5-8 scoops) of the
bottom layer into their cup. This is the oldest layer. Have them repeat the process
for all the layers, attempting to make each one as smooth as possible. There should
be 6 layers total.
Part Two: Read the Past
9. Tell students to swap cups with another team. They will now take a core sample of
the “soil” and attempt to figure out the history of how the layers were formed.
10. Show the students how to take the core sample by pushing a straw straight down
through the layers, then put your finger over the opening on the open end and pull
the straw out. Tell them it will only work if they keep their finger on the straw!
Dust off the outside of the straw if necessary.
11. Tell students to record the core’s history on the other side of their sheet of paper.
They should use words and draw the core. Have one student draw the core while
another one holds the straw.
12. When all teams are done, have them compare their core readings with the original
plan. Are they the same? If not, what happened?
All sugar in layers should be poured carefully into a trash can. All unmixed sugar
should be put back in the containers to be reused. Brush sugar off of all spoons and
cups, and MAKE SURE THE CONTAINERS ARE SEALED.
Sample Charts