Muddying the Waters

Age/Grade Appropriate

Grades 3 through 6

Pre-Visit Activity for Geologist in Your Classroom

Key Concepts

Observation

Drawing conclusions

Background

Badlands National Park is considered a semi-arid environment, meaning it receives between 12 and 20 inches of precipitation per year. There are few reliable water sources to be found. What little water that exists in the park is undrinkable by people or animals. It is full of silt and mud particles and is also extremely alkali. Homesteaders said it was "too thick to drink and too thin to plow."

However, those silt and mud particles are both the past and the future of the Badlands. The White River, which carved the Badlands, is also silt-laden. In fact, it is so full of sediments that it is brown in color. Those particles being carried away are tiny bits and pieces of the formations. It is the long processes of deposition (water-borne sediments being "dropped off" or settling out) or erosion (rocks, minerals, and soil being removed by water or wind) that are the geologic story of all badland formations around the world.

Purpose

To understand what dirt is made of and how sediments settle out of water

Procedure

1. Divide the class into groups of two to four.
2. Fill the jar about half way with dirt. Then fill the jar almost to the top with water. Cover the jar tightly.
3. Shake the jar up and down 20 times to mix its contents. Note: Shake the jar over a sink if you are not positive that the cover is water tight. Caution: Make sure you have a firm grip on the jar. Be extra careful if you are using a glass jar.
4. Put the jar in a place where it will not be disturbed. Allow the dirt to settle. Answer question 1 on the worksheet.
5. Using the spoon, skim off any floating particles and put them on a paper towel. Then slowly pour the water into the small jar. Try not to disturb the layers.
6. Using the spoon, scoop out the top layer and spread it on a paper towel.
7. Repeat step five for each of the layers in the jar.
8. Examine the separated layers visually and by touch. Answer question 2 on the worksheet.
9. Examine the water in the small jar. Answer question 3 on the worksheet.