In this activity, we will model the formation of a cast and mold fossil using natural clay and plaster of paris. We’ll imagine the clay is sediment at the bottom of an ancient ocean floor, in which the mold “fossil” will be created. The plaster of paris represents a second layer of sediment in which the cast ”fossil” will form. We recommend reading the Terms & Facts to Know sheet (opposite side of this page) before beginning so you are familiar with terms used and can include interesting facts as you and your child discuss this project.
