The History of the Earth: Supplemental Guide CA | Culminating Activities 171Explain to students that they are going to make lava. Give each
student, partner pair or group a cup. Fill the cups ¾ full with water.
Add 5 drops of food coloring [optional]. Add ¼ cup vegetable oil to
each cup. Sprinkle 1 teaspoon salt on top of the water. Watch the
lava move up and down in the cup. Add additional salt to keep the
lava moving.Fossils
Materials: Clay, objects with distinct shapes to press into the
clay
Have students create their own fossils by pressing common
objects into clay, such as plastic dinosaurs, etc. Have students
remove the object and allow the clay to harden for a few hours.
Have students discuss what the imprint left in the clay could tell
someone who has never seen the actual object. You may also fi nd
directions on various websites for more sophisticated projects.
Be sure to talk about what fossils are, how they are formed, and
what information they give.Organize Your Fossils!
Materials: Fossils Timeline, Image Cards 10–14, large sheet of
chart paper with a horizontal line down the middle,
[Optional] clock or watch
Display the Fossils Timeline. Review the Image Cards on the chart
with the students, and remove each card after discussion. Remind
students that the Dinosaurs (Image Card 14) came after reptiles
appeared. Divide the class into fi ve groups. Give each group one
of the Image Cards. Have the groups discuss their Image Card and
check to see that each group can identify what is pictured on their
card.
Tell students that the goal of this game is to see how quickly
the class can organize a Fossil Timeline that is the same as the
original Fossils Timeline. Ask each group to select a representative
who will hold their Image Card and stand on the chart paper that
represents a timeline.
Place the chart paper on the fl oor and write 550 million years ago
on the left side and 245 million years ago on the right side. Ask the