Grade Level: Duration: Location: Vocabulary: 3rd – 5th grades
Two class periods and time as needed for research and construction of the diorama.
Classroom setting
Carbonic Acid, speleothems, bat guano
Cave -O- Rama
Introduction:
Caves are formed when rainwater containing carbonic acid erodes layers of soft limestone to form underground
caverns. Seepage of water does not stop when the cave is formed. In most caves, the seepage will continue at a
very slow rate forming rock structures called speleothems such as:
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Stalactites – calcite deposits that hang down from the ceiling
•
Stalagmites – calcite deposits that rise up from the floor
•
Columns – occur when stalactites and stalagmites touch
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Cave pearls – grow in shallow pools saturated with the mineral calcite.
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Cave popcorn - water either seeping out of limestone walls or splashing into a cave, deposits the mineral
calcite in knobby bumps resembling popcorn
•
Helictites - formed when water under pressure is pushed through a limestone wall, forming spaghetti-like
calcite deposits on the other side.
•
Draperies - Water running down a limestone cave wall or along a ledge deposits calcite into delicate
draperies or curtain-like rock forms.
In addition to the many speleothems, plant and animal life inside caves is dependent on factors such as size of
the cave, temperature, humidity, and amount of light. The entrance zone is characterized by sunlight, variable
temperature and humidity, and presence of green plants. The plant life is mainly moss and ferns. Animals such as
owls, bears, and raccoons use this space to eat, sleep, or nest, while snails and salamanders may be more likely to be
permanent residents.
The twilight zone has little light, slightly more stable temperature and humidity, and mushrooms but no plant life.
Animals such as bats, spiders, and moths live in this zone and come and go frequently.
The dark zone has no light whatsoever, no plants, and constant temperature and humidity. Animals such as
centipedes, cave fish, cave spiders, small crustaceans, and blind salamanders living in this zone spend their entire
lives inside the cave. Organic material in the form of bat guano and decaying plants washed in from outside the
cave are an excellent growth medium for fungus and bacteria, which provide a food supply for the other inhabitants
of the dark zone.
Despite the seemingly inhospitable environment, caves provide a complex habitat for the organisms living there.
Engage:
Show students pictures of cave formations and discuss how they are formed. PBS has a series of short
videos on caves and karst that are available for streaming in the classroom: (http://ket.pbslearningmedia.org/
search/?q=caves+and+karst)
Discuss the different zones of a cave with the students and ask them what types of organisms they think would live
in each zone.
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Materials:
• Shoe box
• Different colors of
• modeling clay
•Crayons
•Markers
• Poster board
•Yarn
•Scissors
Explore:
Part I
a. Turn the shoe box on its side.
b. Have students draw the entrance to their cave on the bottom of their box.
c. Carefully cut out the entrance.
d. Use modeling clay (earth colors) to cover the bottom of the box around the entrance.
e. Color the inside of the lid and the inside of the box black.
f. Cover the floor of the cave with modeling clay.
g. Conduct research on the various types of speleothems.
h. Use modeling clay to make the speleothems for the inside of your cave. (Be sure to make stalactites, stalagmites,
and columns. The others are optional.)
i. Tape the top on the box.
j. Use modeling clay to make the ferns and moss at the entrance to your cave.
Part II
a. After discussing the organisms that live in the three cave zones, use a poster board to create a food web for your
diorama.
b. Use yarn to connect the organisms on your food web.
c. Display your food web with your diorama.
Explain:
1. Why are the stalactites longer and smaller in diameter than the stalagmites? (Gravity and slow evaporation
rates for stalactites. When water hits the floor it spreads out in a large circle, forming a larger base for the
stalagmites.)
2. Why are there no plants in the twilight and dark zones? (no sun)
3. Why are many of the animals in the dark zone blind? (no need for eyes)
4. What is the most abundant mineral in speleothems? (calcite)
Elaborate:
1.
2.
3.
4.
5.
6.
7.
8.
Divide the students into two groups.
Take the students outside when the soil is damp.
Have each group find a large rock and turn it over.
Immediately identify and observe the types of organisms living under the rock.
What did the organisms do when the rock was moved? (worms began to burrow, bugs moved out of the light)
Describe the living conditions under the rock. (dark, cool, and moist)
How does the environment under the rock compare to a cave? (both are dark, cool, and moist)
Explain that many of the same organisms which live under rocks also live in caves.
Extension:
1. If there is a nearby cave that conducts tours, plan a field trip for your students.
2. After the field trip, have the students identify and discuss the major rock features and environmental conditions
in the different zones of the cave.
Evaluate:
1. Invite other classrooms to view the students’ dioramas and food webs.
2. Have each student explain their display to at least one other student.
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KENTUCKY CORE ACADEMIC STANDARDS ALIGNMENT
Science
• 3-LS2.D: Social Interactions and Group Behavior
• 5-PS1.B: Chemical Reactions
Suggested Reading/Resources
1. Caves (True Books: Earth Science) by Larry Dane Brimner
2. Caves and Caverns by Gail Gibbons
3. Caves (Landforms) by Cassie Mayer
4. Castles, Caves, and Honeycombs by Linda Ashman
5. Bats: Creatures of the Night by Judith Moffatt
6. Stellaluna by Janell Cannon
7. Trouble in Troublesome Creek by Nancy Allen (http://www.nancykellyallen.com/trouble-in-troublesome-creek.
html)
8. One Small Square: Cave by Donald M. Silver and Patricia Wynne
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