STUDENT WORKSHEET
CLIMATE DETECTIVES (L/O/A)
Name______________________________
ACTIVITY - POLLEN PUZZLE
1.
Date___________________
4. Using the descriptions in the Pollen-Climate Key
Sort the foam “pollen grains” in your sample, by
color. Each color of foam dots represents a
different species of plant.
2. Match the colors of the dots to the colors on the
Pollen-Climate Key, to determine the species for
each sediment layer.
3. In the table below, for each sediment layer (1, 2, 3)
and the species you identified in the pollen
analysis on the front of this worksheet, for each
sediment layer determine the biome at the time
the layer was formed., and record the biome
name in the table below .
BIOMES vs. SEDIMENT AGE
BLACK HAWK LAKE
(ybp = years before present)
mark an X for each species your team identifies.
Sediment
Layer
POLLEN ANALYSIS
BLACK HAWK LAKE
Plant
Species
Sediment Layer
1
2
3
1
150-450
ybp
2
450-650
ybp
3
650-1500
ybp
alpine sage
bristlecone
pine
Douglas fir
Engelmann
spruce
limber pine
meadow
grasses &
wildflowers
ponderosa
pine
sedges &
mosses
Age
Biome
5. Based on the biomes recorded in the table above,
how did the climate change from 1500 to 150
years before the present?
6. Can you speculate about what might have
caused this climate trend? What do you think
might have happened? (You may know the
answer to this from what you learned in a world
history or European history class!)
7. From this single lake sediment core can you make
conclusions about global climate trends during
1500-150 ybp? If not, what additional evidence
should you investigate?
ACTIVITY – FINDING “NEO”
1. 1. For each of the three foram samples (10 thousand, 15 thousand, and 20 thousand years before
2.
present), count the total number of Neogloboquadrina forams and record the number in the table
3.
below, in the appropriate rows.
2. 2. Next count the number of right-coiling “Neos” in each sample and record these numbers in the
3.
table.
Sedime TOTAL Rightnt Layer “Neos” coiling
“Neos”
3. For each sample, calculate and record the
percent of right-coiling “Neos”:
percent = number of right-coiling Neos X 100
total Neos in sample
4. Determine the relative ocean temperature
(cold, warm, in-between) for each sample,
based on the percents you calculated.
1
10,000
ybp
5. What happened to the ocean temperature
2
15,000
ybp
6. What might have caused this temperature
3
20,000
ybp
between 20,000 and 10,000 years ago?
Percent
Relative
RightOcean
Coiling
Temperature
“Neos”
trend?
ACTIVITY – STOMATA SPECTACULAR
1.
For each fossil leaf, count and record the number of stomata in the 3 areas of the “microscope slide”. Next
calculate the average of the three counts and then divide that average by the area of the microscope’s field of
view, to determine and record the stomatal density.
2. From the stomatal density, determine the relative carbon dioxide levels (higher or lower) for each of the two
time periods.
FOSSIL AGE
STOMATA
IN 1st AREA
STOMATA
IN 2nd
AREA
STOMATA
IN 3rd
AREA
AVERAGE
OF THREE
AREAS
AREA
(FIELD
STOMATAL DENSITY = CO2 HIGHER
AVG./0.05 mm2
or LOWER?
OF VIEW)
15 million
years
0.05
mm2
13 million
years
0.05
mm2
3. Other scientific field evidence shows that 15 million years ago, the world’s icecaps and glaciers decreased in size,
and about 13 million years ago there was major growth of glaciers and icecaps. How might these changes be
related to the results of your stomata study?
4. Are the atmospheric changes the result of natural causes or human activities? What factors or phenomena may
have caused the changes?