Learn by Doing

How Do Streams Weather Rocks?

• 1. Place some small, freshly broken pieces of rock or brick in a large plastic jar. Softer rocks such as sandstone, shale, or limestone work best.

  2. Fill the jar about halfway with clear water.

  3. Put aside some other pieces of the broken rock.

  4. Close the lid of the jar and shake it 1,000 times.

  5. Remove the rocks and note any changes in their appearance compared with the rocks that were not shaken.

  6. Describe these changes in learning logs.

  7. Filter the water through a piece of filter paper or funnel lined with paper towels.

  8. Questions: What do you see in the filter paper? What might happen to rocks in a stream or river? (Rocks in streams and rivers are weathered by water and movement.)

How Does Water Carry Particles of Rock and Soil?

• 1. Mix some gravel, sand, mud, silt, and clay in a large jar.

  2. Add water to the jar.

  3. Cover the jar with the lid; then shake the jar vigorously.

  4. Have students observe the jar over a period of time and note Learning Log how long it takes for the different materials to settle on the bottom.

  5. Questions: Do they see different layers on the bottom? What is different about them? Have students think about different kinds of streams and rivers. Where would they expect to find a rocky or gravel bottom? Where would there be a muddy or silty bottom? Which type of material might be carried for the longest distance? (The smaller particles remain in suspension in the water for the longest time. They have a larger ratio of surface area to mass and therefore experience more resistance from the water as they sink.)

How Do Chemicals Weather Rocks?

• 1. Place an equal number of limestone or marble chips and other kinds of rocks in each jars.

  2. Cover the stones in one jar with water and those in the other with vinegar; then screw lids on the jars. Allow the jars to stand overnight. You may notice some bubbles forming in the jar with the vinegar.

  3. Ask the students to speculate about what this might mean in learning logs.

  4. The next day, pour out the liquid from each jar into separate bowls. Label the bowls "water" and "vinegar".

  5. Allow the water in the bowls to evaporate.

  6. Compare the amount of solid material remaining in the two bowls.

  7. The bowl that contained vinegar will have a larger amount of solid material.

  8. Questions: Is it limestone, marble, and other carbonate rocks? How did they react with acid to form carbon dioxide and soluble salts? Rainwater is often acid and can erode limestone easily.How does acid groundwater dissolves limestone underground, forming caves and sinkholes?

Wave Action - How Beaches Are Formed

• 1. Slope a generous amount of sand against one end of a dishpan.

  2. Add water until the sand is about half covered.

  3. Use the side of a ruler to generate steady, even waves in the tray.

  4. Have students observe the action of the waves on the sand.

  5. Questions: How does the water removes sand from the upper part of the "beach" and deposits it below the waterline? This is how sandbars and barrier islands are formed. Make very small, rapid waves, you may see that the sand is redeposited on the beach.

Small and Whole Group: Discuss, share and record concepts and questions in Learning Log.

Vegetation - How Does Vegetation Affect Erosion?

at least a week before

• 1. Punch holes in the bottom of a plastic cup to make a sprinkler.

  2. Place three to five centimeters of soil in each of two planting flats.

  3. Sprinkle grass seed on the soil in one of them and cover lightly with soil.

  4. Water both flats every day with the sprinkler until the grass is five centimeters tall.

  5. At least a week later

  6. Prop the ends of both flats up at a moderate angle with bricks or blocks.

  7. Sprinkle each flat with water equally until you observe soil erosion.

  8. Questions: In which tray did the soil erode more? What might be the effect of removing plants like trees from a steep mountainside? How could soil erosion be controlled in steep places? What other factors can students think of that would affect the amount of erosion? Have students identify any areas in your community that are steep.

  9. Optional: Take a field trip to look for signs of erosion. A walking field trip around the schoolyard and neighborhood, go to a local park and allows students to observe the effects of vegetation on the environment and relates to weathering and erosion.

Visual Art and Erosion: Andrew Goldsworthy

https://educationcloset.com/2016/02/02/steam-lesson-erosion-art/

Whole Group: Discuss, share and record concepts and questions.

Use data to develop questions in Learning Log for final entry.

Weathering Lab Stations

Materials: carbonated water, tap water, rock samples.

Test rock samples in carbonated water vs. tap water.

Observations are taken initially, at 20 minutes, and after 24 hours.

Materials: tap water, cup

Test to show that water expands as it freezes.

Mark on a cup the water level before freezing and after freezing.

Materials: vinegar, pennies

Test the effects of vinegar (acid rain) on copper (pennies). Here you should record observations initially and then after 5 minutes.

Materials: antacid tablets, tap water

Compare and record the reaction of antacid tablets in water. The comparison is a whole tablet vs. crushed tablet.

Materials: limestone, vinegar, and tap water

Compare and record the reactions of chalk (limestone) in water and vinegar.

Materials: steel wool, tap water

Test and record the effect of water on steel wool.

Materials: sugar cubes, gravel, and small jar

Test and record the effects of sugar cubes and gravel shaken together in a jar.

Erosion Lab Stations

Materials: sand, pan, tap water

Demonstrates beach erosion. Using a pan, make a sand pile at one end and pour water at the other end.

Slide the pan back and forth to create wave movement.

Materials: ice cube, plastic cup, warm water

Place an ice cube in a plastic cup of warm water. See what the effect is.

Materials: sand frozen in ice cube, sand, water, dirt, etc.

Freeze ice cubes with sand in them and then move the sand ice cubes over different surfaces, sand, water, dirt, etc.

Materials: sand, hair dryer

Place sand in a small bowl and the use a hair dryer to move the sand. Note if different speeds are possible.

Materials: ice cube, dirt

Place a pile of ice cubes on a mound of dirt. Observe and record what happens as it melts.