Make Your Own Cave
OBJECTIVES: Students will avoid touching artificial speleothems while using large motor skills to negotiate an obstacle course.
MATERIALS: Large cardboard box (such as a furniture or appliance box), yarn, large nail, plastic drinking straws, large plastic cups, wooden dowel (height of the box width) tape
BACKGROUND: Speleothem is the name given to any secondary deposit (decoration) inside of a cave. The main types are stalactites, which hang down from the cave ceiling, and stalagmites, which rise up from the cave floor. Formation of any speleothem takes an extremely long period of time. As each drop of water leaves a tiny amount of mineral residue on a cave ceiling, floor, wall or other feature, it adds to speleothem growth. When a speleothem is broken, it will not be replaced within our lifetime, if ever! Therefore, cavers must be extremely careful while exploring.
PROCEDURE: The cave obstacle course is made up of drinking straws stalactites, plastic cup "stalagmites", and a large cardboard box. Lay the box down so the two ends are open. Brace the center of the box with the wooden dowel "column". Punch a hole in the top of the "cave" with the nail. Thread yarn through one drinking straw and then through the nail hole and knot to secure it. Hang numerous straws, at various levels, in one area of the cave. Allow enough room for the students to wriggle around without touching them. Make the stalagmites by taping large plastic cups together end to end, or mouth to mouth. Stalagmites can be one to three cups high. Mark a trail with the stalagmites leading to one open end of the box, through it, and out the other end to represent an area of the cave where the explorer can stand upright. The cavers will need to crawl in the area represented by the box.
Instruct the students that they are to be cavers exploring a little known cave. It is their responsibility to not damage any speoleothems. Briefly talk about stalactites and stalagmites, to familiarize the students with the terms.
When they reach the box, the students will crawl through, not hitting any stalactites or stalagmites. When each student has had a chance to negotiate the "cave", lead a short discussion on maneuvering methods that the students invented or used. Have the children try another trip through the cave to see if there has been any improvement from their first trial.
Follow Up: As you tour Round Spring Cave, remind students of their obstacle course experience. Point out speleothems that have been touched or broken. Look for signs of renewed growth of broken speleothems. Encourage students to protect the cave as they go through it, and to be aware of their effect upon the cave.