Fossils Experiment

Today we talked about fossils and made a do it yourself fossil dig sites in groups.

A fossil is the remains or impression of a prehistoric organism preserved in petrified form or as a mold or cast in rock.

Our task is to create a matrix and determine which plaster/sand mixture is the best. My group and I did 3 different ratios, 25mL Plaster/75 mL Sand, 50mL Plaster/50mL Sand, and 75mL Plaster/25mL Sand. We added water to each mixture until we made a solution that had a pancake batter like consistency. Below is a picture of the 3 cups. Inside of the solutions is a shell for us to find later.

After letting the solutions dry for a week, we used hammers and chisels to find the shells that were hiding. Cup 3 was the best solution, which had 25mL plaster and 75mL sand. It was easy to break the solution up and my group partner just had to use her hands to find the shell. This would be great for young kids because they wouldn't have to use tools to break it apart. On the other hand cup 1 and 2 were much harder, and it took my other group partner and I a while to find the shell, having to use hammers and chisels. This would be hard for an elementary student get the shell, but it would also be dangerous giving a 2nd grader a hammer.

This was a great activity and I can not wait to do this in my classroom.