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Photo:
Bettmann/CORBIS
| OTHER MINI-LESSONS |
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Caves are natural openings
within the earth that usually extend deep beyond the reach of light. They are found in many types
of rock, but are most common in limestone and gypsum. These caves were formed by water under
the surface of the earth. A second type of cave is the lava cave, formed as liquid lava flows.
A third type of cave is the sea cave. Sea caves were formed along cliffs and rocky seashores.
The study of caves is known as speleology, and those who explore caves are called
speleologists.
- Introduce your cave unit by making a list on the chalkboard of the facts your students
already know about caves. What words come to mind when they think about caves?
While your students are probably familiar with the popular image of caves,
they may be surprised by how few facts they know.
- Visit some of the cave Web sites below to give your students a brief look at
the great variety of caves.
- With a simple science experiment, help your students understand how caves form.
Give each student six ounces of clay and a dozen sugar cubes.
The clay will represent sandstone, a hard rock, and the sugar, limestone.
Working on a newspaper-covered surface, students should mold the clay around the sugar cubes,
being careful to leave at least part of a sugar cube exposed. By arranging the sugar cubes,
they will be determining the shape of their caves. When students have finished constructing the caves,
leave the caves to dry for several days, and then soak the structures in water. The sugar will dissolve,
leaving the hollowed out spaces.
- Give your students experience in writing lab reports. Ask them to record their process and
observations at each stage. Then ask them to reflect on what they have learned about cave formation.
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