Lab: Weathering (chem & mech) and Erosion

Model # 1: How does wind carrying sand (sediment) affect different types of rocks?With this model you will investigate how wind affects rocks. To model the sand and dirt particles caught in the wind and blown over rocks, you will use sandpaper.

Materials:• Sandpaper: 50 grain or similarly coarse sandpaper will work best• Rock samples: Rough samples of a soft stone such as calcite, limestone, dolomite, fluorite, rhyolite or similar stone

Procedure:1) Choose two different rock samples and write down careful observations of before

column of your data collection organizer.2) Using a small piece of sandpaper, rub the sandpaper over the rock samples.3) After five minutes of rubbing the rock samples, take another look at them. Record your new observations in the

after column of your data collection organizer.4) When you’re finished, set aside the rock samples you’ve used so that the next group doesn’t use the same ones.

Model # 2: What happens to rocks when water in the cracks freezes?With this model you will investigate how freezing and thawing water in the cracks of rocks can alter them over time. You will explore properties of water and ice in a plastic cup as a model for water and ice in rock.

Materials:• One clear plastic cup• A marker to label and mark the cups

Procedure:Day 1

1) Fill a cup halfway full with water.2) Using the marker, carefully mark the water level on the cup and record observations

in the before column of your data collection organizer.3) Write your names on the cup and give it to your teacher to freeze over night.

Day 21) Using your marker, carefully mark the new water level on the cup.2) In the after column of your data collection organizer, record how the initial water level compares to this new water level.

Model # 3: How does acid rain affect copper-bearing rocks?With this model you will investigate how acid rain affects copper-bearing rocks. To model acid rain, you will use vinegar with a little salt added. To model copper-bearing rocks, you will use pennies which contain small amounts of copper.

Materials:• 2 copper pennies• 2 beakers• Approximately 1 tsp. of salt• Vinegar• Water• Pair of tweezers to remove the penny for observation

Procedure:Day 1

1) In the before column of your data collection organizer, record your observations of the two pennies.2) Place one penny in each of two beakers.3) Using the tape and a marker, write your names on each beaker.4) On one beaker, write “Acid Rain” on the label.5) On the other beaker, write “Pure Rain” on the label.6) In the beaker labeled “Acid Rain,” sprinkle 1 tsp. of salt over the penny and then add enough vinegar to cover the penny.7) In the beaker labeled “Pure Rain,” add enough water to cover the penny.8) Set these beakers aside for 10 minutes and then take another look. Record your observations in the 10 min after

column of your data collection organizer.9) Does the “acid rain” penny look different from the “pure rain” penny? How? Describe what the pennies look like in in the

after column of your data collection organizer.10)Set them aside again and take another look tomorrow.

Day 21) Use the tweezers to take the pennies out of the beaker to get a closer look. Record your observations in the 1 day after

column of your data collection organizer.

Model # 4: How does water affect carbonate rocks?With this model you will investigate how water affects carbonate rocks. To model this you will use antacid tablets (Alka-Seltzer is one brand of antacid tablets) that contain carbonates.

Materials:• 2 Alka-Seltzer or other brand antacid tablets• A small beaker• Water• Pair of tweezers to remove the tablet for observation• Timer or clock

Procedure:1) Take a look at the Alka-Seltzer tablet and record your careful observations in the

before column of your data collection organizer.2) Place one tablet in a small beaker and cover it with water.3) Make careful observations for 3 minutes. Use the timer or a clock to watch the time.4) After 3 minutes, use the tweezers to remove the tablet and then record your

observations of the surface of the tablet in the after column of your data collection organizer. Compare the tablet to an unused one to make sure your observations are accurate.

Model # 5: How does water affect limestone rocks? How does acid rain affect limestone rocks?With this model you will investigate how water and acid rain affect limestone. To model limestone you will use chalk, which is a type of limestone. To model acid rain, you will use vinegar.

Materials:• 2 pieces of chalk• A mortar and pestle• Water• Vinegar• 2 small beakers• Pair of tweezers to remove the chalk for observation

Procedure:1) You need to have pebble-sized pieces of chalk for this experiment. If you

need to, use a mortar and pestle to break the chalk into smaller pieces.2) In before column of your data collection organizer, record your observations of the chalk. How does it feel? What does its

surface look like?3) Place half of the chalk pieces in one beaker and label it “Acid Rain”.4) Place the other half of the chalk pieces in the other beaker and label it “Water”.5) In the beaker labeled “Acid rain” cover the chalk with vinegar.6) In the beaker labeled “Water” cover the chalk with water.7) Record your observations in the immediately after column of your data collection organizer. 8) After waiting about 3-5 minutes, you can try to take the chalk pieces out of the beakers if you want to make additional

observations. Otherwise, record your final observations in the 3-5 min after column of your data collection organizer.

Model # 6: How do rocks scraping against each other in a stream affect different types of rocks?With this model you will explore how rocks are altered by collisions with each other caused by ocean waves, falling down a rocky mountain slope in a rock or snow avalanche, or tumbling down a turbulent river. To model rocks of different hardnesses you will use gravel (a harder rock) and sugar cubes (a softer rock). Shaking them will mimic the vigorous motion that occurs in ocean waves, rock avalanches, or riverbeds.

Materials:• Sugar cubes (approximately 5-7)• One jar with lid• Gravel (a small handful)

Procedure:1) Pick out 5-7 sugar cubes and record your observations of the sugar

cubes in the before column of your data collection organizer.2) Pick out a handful of gravel and record your observations of the gravel in the before column of your data collection

organizer.3) Put both the sugar cubes and gravel in a jar and close the lid tightly. Then shake the contents of the jar vigorously for

about 5 minutes. You and your partner may need to take turns so you don’t get tired.4) After five minutes open the jar and look carefully at the sugar cubes and gravel. Record your observations in the after

column of your data collection organizer.5) Now, write down your thoughts on how abrasion (whether tumbling down a mountain, being tossed around in waves, or

washed down a riverbed) might affect different types of rocks.

Model # 7: How do waves impact beaches?With this model you will investigate how waves impact beaches. To model a beach you will create a patch of sand on one end of a large pan and then slosh water back and forth inside the pan to model waves.

Materials:• Large plastic container (at least shoebox size)• Water• Sand (enough to make a “beach” at one end of the pan)

Procedure:1) Using dry sand make a “beach” at one end of the pan. Pack the sand down,

smooth it out, and then record your observations of what your beach looks like in the before column of your data collection organizer.

2) Make sure there is water in the pan and then slowly slosh the water back and forth to model waves washing up on the shore of your beach. Watch what happens to the beach the longer you do this.

3) Record your observations in the after column of your data collection organizer after you’ve experimented like this for about 5 minutes.

4) Write down your thoughts about how waves alter beaches. Make a prediction about what would happen over a long time period if the waves continued to do this to the beach.

5) Now, record whether you think this exploration demonstrated chemical weathering, mechanical weathering, or erosion.6) When you’ve finished, scoop out any wet sand so that the next group can make a fresh new beach when it’s their turn

to explore this station.

Model # 8: How does gravity affect hillsides, mountainsides, and cliffs? With this model you will investigate how gravity affects hillsides, mountainsides, and cliffs. You will model the hillside/mountainside/cliff by creating a pile of sand that is as tall as you can make it.

Materials:• sand and pebble mixture• 2 plastic cups• water pipette

Procedure:1) Pack the sand and pebble mixture into one of the plastic cups. Make sure it is packed tightly. 2) With the cup close to the surface of the area where you are working, quickly turn it upside down onto the surface. Then,

very slowly, pull the cup up and off. 3) Note your observations in the before column of your data collection organizer. 4) Use the pipette to drop water on the top edge of the mountain model.5) Note your observations in the after column of your data collection organizer.6) Break down your model mountain and place it in the cup again, then set it to the side.