You will need, Graham Cracker Crumbs (Dirt), Cocoa Puffs (Rocks) and Gummy Dinosaurs
Have the kids crush up the graham crackers themselves so they understand that it's really not dirt! Then have them layer the ingredients in the above order. This is a great way to teach them patterning. They loved digging up their dinosaurs and they all thought it was funny that they were eating "dirt" and "rocks"!