LET'S MAKE FOSSILS

MATERIALS

1/2 cup cornstarch
1 cup baking soda
5/8 cup cold water
wax paper
leafs, bones, shells

PROCEDURE

Have an adult stir first 3
ingredients over medium heat.
Shape into about a dozen one inch balls.
Flatten a ball onto wax paper.
Press a leaf, bone, or shell into the dough.
Remove the leaf, bone or shell, leaving
an imprint.
Allow to dry.

EXPLANATION

Fossils are found in sedimentary rocks.
Prerequisites for fossils are:
1) organisms must be hard, such as bones,
teeth, shells
2) they must be in an oxygen-free environment,
away from predators
3) they must be in favorable heat and pressure
conditions

Four types of fossils:
1. Petrified fossils
Examples are porous wood or bones. Minerals seep
in, turning the porous material into stone.
2. Carbon fossils
Water and gas are squeezed out of the material,
leaving only carbon.
3. Molds and casts
The material leaves a hole in the rock in the
exact shape of the original specimen.
4. Trace fossils
Signs are left behind by an organism.
Examples: footprints, nests, burrows