7. Erosion Patterns - Logistics

15 minutes – Set stage for the experiment
20 minutes – Run single sediment and mixed sediment rivers side by side
15 minutes – Teams make individual conclusions and clean up
15-20 minutes the following class period – Combine all data and make summative conclusions

Teams of 3-4 students. Half the teams will set up tubs with a single sediment (diatomaceous earth). The other half will set up tubs with a mixture of sediments (diatomaceous earth, playground sand, and aquarium gravel).

For Soil Separation Test Demonstration

  • 1 small jar alum (available at supermarkets for pickling)
  • 1 clear Mason jar with lid

For River Models
For each team of 3 students:

  • 1 wide-mouthed, 9 oz plastic cup with a V-shaped notch cut into the edge
  • 1 plastic stir stick
  • 1 straightened paper clip , approximately the same length as the stir stick and thin enough to be inserted into one of the 2 holes in the stir stick
  • 1 plastic food service tub, approximately 20”x15”x7”
  • 1 piece of wood (1”x2” stakes are cheap and easy to find although they do have splinters) or other prop to raise one end of the tub off the table

For the class to share:

  • 20 lbs of diatomaceous earth (see Sources for more information)
  • 10 lbs aquarium gravel
  • 10 lbs playground sand
  • measuring cup
  • sponge
  • several pitchers of water
  • blue food coloring
  • paper towels (for clean up)