For the Kids…Coffee Ground "Fossils"
Article by: Greenhouse staff
Some plants have been on earth for thousands of years, but have changed significantly over time. How do scientists know what plants looked like thousands and even millions of years ago? They use fossils!
Conditions have to be just right for fossils to form. For instance, if a tree drops a leaf onto the muddy bottom of a lake, and that mud is allowed to dry out and turn to stone – a fossil may be left behind.
You can make fossils of your own. You can make imprints of leaves, seeds, grasses, twigs, toys or even your finger print!
Mix in a bowl:
• 1 cup of used coffee
grounds
• ½ cup of cold coffee
• 1 cup of flour
• ½ cup of salt
Once the ingredients are well mixed, turn the dough out onto a sheet of waxed paper. Knead the dough until it no longer sticks to your fingers. You may need to add more flour to get the consistency right.
When the dough is ready, pread it out on the wax paper and use a cup, can or cookie cutter to cut out small circles.
Press small objects into the dough to leave behind impressions. You may want to use a small amount of flour or oil on the object to prevent it from sticking. You can coat the object with washable ink or paint to make the imprint show up better.
Poke a hole in the edge of your fossil if you want to hang it on a string and set it out to dry overnight.
If your fossil does not dry out completely you can bake it in the oven until it is hard. (Get an adult to help.)
