Here are a number of ideas for investigating and finding out about what makes up sedimentary rock.

1. Mix up an assortment of clay, sand, mud, and water in a tall glass. You could add a few leaves and small twigs. Watch it settle into layers over a few days.
2. Talk about fossil formation, rock layers, weathering from storms, floods,
3. Look at photos of sedimentary layering and sedimentary rocks
4. Drilling for fossils

• You will need 3 or 4 different colours of playdough
• Form into different layers
• Add small bits of different colour (fossils) and hide in the layers
• Use a drinking straw to drill core samples - it may help to cut a 2 cm slit in the end of the straw.
• Discuss core sampling, layers, fossils found, damage to core when extracting it.

http://www.icair.iac.org.nz/science/roberts/