Making Sedimentary Rocks
Worksheet
Pages 11-12
Procedure
• Follow the directions
• Place materials in order
• Color and label each layer/
Fossil
*** Each group had a
different procedure.
8
7
6
5
4
3
2
1
How do the layer thicknesses in your
container relate to sedimentary rock
layers in real life?
• They vary in thickness
– Some layers are very thin and some are thicker
Why are the layers different
thicknesses in real life?
• Erosion / weathering happen at different rates
each year
– More erosion = larger layer
• Events like volcano eruptions/dust storms
don’t happen every year
– Can create larger layers
How do the layer colors in your
container relate to sedimentary rock
colors in real life?
• Colors in real life are more earth tone
– Brown, Beige, Tan, etc
• In real life the colors still vary
Why are the layers different colors in
real life?
• Different types of rocks are eroded and
deposited
• If an event occurs it would produce a different
color than normal
What challenges did you have with this
lab?
What challenges do you think you
might have when you have to take
each individual layer apart to create
the fossil record?
Sedimentary Rock Worksheet
Page 14
Picture 1
• Which shell is the oldest?
–C
• There are no shells in Layer 3,
why might this be?
– Nothing to preserve them
– Migrated
• No dinosaur bone is found below Layer 2, this
might mean:
– They weren’t around that long ago / haven’t evolved
yet
– Conditions weren’t right to preserve them
– They lived in a different area
Picture 2
• If you also found a softdrink can in layer 3, what
could you say about Layers 3,4, & 5
– Humans were around
• Are there likely to be dinosaur bones in any of
these layers? Explain.
– Wrong picture (see below)
– No. Humans didn’t coexist
with dinosaurs
Picture 3
• List the layers in order from oldest to youngest
– E/B – D -- A/C
• In diagram I, which layer is the same as Layer
A?
–C
• What can you say about the top layer in
diagram I?
– Formed after the fault
happened
– Humans were around
Relative vs. Absolute Time
Page 15 - 16
Example Time Scale
Relative Time Scale
Absolute Time Scale
I was born.
I was born.
August 21, 1985
I took my first
steps.
My little sister was
born
First high school
RBI
Graduated high
school
I took my first
steps
My little sister was
born
First high school
RBI
Graduated high
school
Graduated college
Graduated college
May 31, 2008
Got my first job
Got my first job
August 26, 2009
Today
Today
November 30,
2013
July 15, 1986
May 30, 1988
March 21, 2001
May 28, 2004
What events did you use in your scale?
Describe how we determine relative
time
• Look at the rock layers to see what is before
and after
• Create a basic timeline/scale
Describe how we determine absolute
time
• Radioactive decay information
• Determine the number of elements / atoms in
the sample and compare it to what we expect
the element to do
Why are both relative time and
absolute time used to reconstruct past
timescales?
• Relative Dating
– Pro
• Works for long time periods
– Con
• Folding/ Faulting / Layers change
• Absolute Dating
– Pro
• Very accurate/ Precise
– Con
• Only works up until a certain time period
Radioactive Half-Life
Pages 17-19
Data
Generation
Pennies
0
100
1
52.36364
2
26.09091
3
12.5
4
6.090909
5
3.318182
Graph
What did the pennies represent?
• Parent Element
What did each trial represent?
• Half-Life
What pattern do you notice?
• Numbers go down by approximately half every
time
Generation
Pennies
0
100
1
52.36364
2
26.09091
3
12.5
4
6.090909
5
3.318182
How does your data compare to the
class data?
Generation
Pennies
0
100
1
52.36364
2
26.09091
3
12.5
4
6.090909
5
3.318182
Compare your graph with the “HalfLife of Carbon-14” graph on the right.
What similarities do you see?
• Same basic shape
• Line has a downward slope
How can knowing an elements half-life
help you determine the age of a fossil?
• We can compare the amount of an element in
a fossil to the graph of expected change
• This gives us an approximate age based on
half life
Why do you think we replaced the
heads up pennies with paperclips?
Why was there always 100?
• Matter isn’t created or destroyed
– Atoms were changed but weren’t destroyed