Weathering and Erosion Application Sequence

Part I: Information about the Lesson and Unit

Topic: Weathering and erosion, part of a unit on weathering and soil.

Abstract

In this three-day application sequence we will introduce the problem of how weathering and erosion shape the surface of the earth. On day one we will watch and discuss a video to make sure the students can differentiate between weathering and erosion. We will then introduce two PEOE activities and use one of them tomodel an explanation of rockslides using weathering and erosion. We will coach the students in developing a good explanation for the second PEOE by giving them criteria for a complete response and walking around answering questions. On day two, the students will move through lab stations that exhibit more weathering and erosion examples and develop their own explanations for each activity. On day two we will coachby providing criteria for a complete response, and by stopping the class periodically to check that their responses have all of the criteria. On the final day, we will fade and students will need to develop good explanations for real world geological features.

Part II: Clarifying Your Goals for the Topic

A. Big Ideas

Earth’s systems are dynamic; they interact over a wide range of temporal and spatial scales and continually react to changing influences, including human activities. Components of Earth’s systems may appear stable, change slowly over long periods of time, or change abruptly (ESS2-A).Earth’s surface is impacted by large time and spatial scale sub-surface processes (plate tectonics) and small time and spatial scale surface processes (weathering and erosion).

Water plays an important role in shaping Earth’s surface. It participates both in the dissolution and formation of Earth’s materials. The downward flow of water, both in liquid and solid form, shapes landscapes through the erosion, transport, and deposition of sediment. Water’s movements—both on the land and underground—cause weathering and erosion, which change the land’s surface features and create underground formations (ESS2-C).

Weathering is the breaking down of rock into smaller pieces. Over time, rocks crack, crumble, and are broken up by water and wind. Drops of water on a rock may repeatedly freeze and melt, causing the rock to crack. Water may react with some of the chemicals in a rock and cause part of the rock to break down. Rocks sometimes fall from higher places, breaking as they fall. Small animals and the roots of plants also contribute to the weathering of rock when they burrow into the ground. Weathering forms sediments that can be moved by wind and water.

Erosion is the movement of sediments from one place to another by water, wind, or ice. When water erodes the earth’s surface, it cuts into the ground, forming surface channels. These channels can range from tiny depressions in the earth to huge canyons, such as the Grand Canyon. Slow and steady water erosion over long periods of time has created valuable features of the earth’s landscape such as lakes, rivers, hills, canyons, and fertile plains.

1. Naming key practices

On day one, we establish the problem “How does weathering and erosion shape the surface of the Earth?”. Our goal is to use weathering and erosion (the model) to explain some of the various geological features on Earth (using models 2b and constructing explanations 6). Students should have prior knowledge of the model (weathering and erosion) from previous classes so we spend less time developing knowledge. The three days are meant to have students practice using the model and understand how it can be used to explain many different observations, geological features on Earth (constructing explanations 6).

The mini PEOE will have students Predict, Explain, Observe, and Explain what happens when we shake a container of sugar cubes and pebbles. This is the left arrow, inquiry: developing knowledge. Students are asking questions (1), carrying out investigations (3), analyzing and interpreting data (4). The teacher will model how to engage in argument from evidence (7) so this is not a true PEOE as we are also using this activity as part of our modeling in the EMCF sequence, which will take place over the 3 days.

General Practices:

During our lessons, students will obtain, evaluate, and communicate information (8) both orally and in writing.

C. Performance Expectations for Student Learning

Performance Expectation / Associated NGSS Practice
NGSS Performance Expectation(s)
1. Construct an explanation based on evidence for how geoscience processes have changed Earth's surface at varying time and spatial scales. (MS-ESS2-2)
Clarification Statement: Emphasis is on how processes change Earth’s surface at time and spatial scales that can be large (such as slow plate motions or the uplift of large mountain ranges) or small (such as rapid landslides or microscopic geochemical reactions), and how many geoscience processes (such as earthquakes, volcanoes, and meteor impacts) usually behave gradually but are punctuated by catastrophic events. Examples of geoscience processes include surface weathering and deposition by the movements of water, ice, and wind. Emphasis is on geoscience processes that shape local geographic features, where appropriate.] / Constructing explanations (6)
2. Develop a model to describe the cycling of Earth's materials and the flow of energy that drives this process. (MS-ESS2-1)[Clarification Statement: Emphasis is on the processes of melting, crystallization, weathering, deformation, and sedimentation, which act together to form minerals and rocks through the cycling of Earth’s materials.] [Assessment Boundary: Assessment does not include the identification and naming of minerals.] / Developing models (2a)
Specific Lesson Objective(s)
1. Construct an explanation on how weathering and erosion shape Earth’s surface resulting in various geological structures. / Constructing explanations (6)

Part III: Classroom Activities

A. Storyline for the Lesson Sequence

Stage / Role in Storyline
Lessons before your sequence / Students will have prior knowledge about weathering and erosion as they will have finished the chapter “Weathering and Soil” in their book and it’s related worksheets and activities. They have some more familiarity with Erosion on a previous unit on the Rock cycle.
Section 1 of the chapter deals with weathering. They learn that weathering processes weaken and break apart rock material into smaller pieces. The should be able to differentiate between chemical and mechanical weathering. The chapter also briefly touches on the fact that weathering shapes Earth’s surface which is the topic we focus our 3 day lesson on.
Section 2 and 3 focus on Soil- its nature and its erosion. The should understand that soil is a mixture of weathered rock, decayed organic matter, mineral fragments, water, and air. They should also know that soil erosion is harmful because plants do not grow as well when topsoil has been removed.
Lesson 1 / We will address the difference between weathering and erosion in order to connect with previous lessons and reinforce the idea that the processes are unique from each other. We will then introduce the problem of how the earth is continually being shaped by the two processes. By shaking sugar cubes in a can, we will demonstrate how rock slides shape rocks. We can say that it is analogous to pebbles getting worn down in a streambed, but in that case the medium transporting the pebbles is water. Then, we will model a complete explanation of this example for the students.
Lesson 2 / The students will visit four lab stations and observe different forms of weathering and erosion. They will use their observations to conduct quality explanations for the processes happening at each station. We will move from group to group ensuring that they are writing good explanations, and their packets will have scaffolding (specific response criteria).
Lesson 3 / Students will investigate real world geological features as case studies. They will construct explanations for how the features form. They have had practice constructing explanations for the activities in day two, so they will apply this practice to the case study. We will fade by checking in periodically with individuals, but no longer for each example.
Lessons after your sequence / After our sequence, students will come back from spring break and begin a unit on soil and fossils.

B. Activity Sequence Details

Focus Objective

Objective / NGSS Practice
1. Construct and explanation on how weathering and erosion change the appearance of Earth’s surface. / Constructing explanations (6)

1. Application Cycle

Examples and Scaffolding (Pattern in Student Practices)

List of examples

1. The rounding of rocks in landslides using the sugar cube experiment.

2. Chemical/mechanical weathering with bar of soap.

3. Rock slide video

Stations:

4. Pouring water on a pile of sand.

5. Blowing sand

6. Ice wedging

7. Adding pipe cleaners to sand to reduce soil erosion

Case studies:

8. Cliff Collapse

9. Jump-Off Joe

10. Land Slide in Italy

11. The Dust Bowl

12. Michigan Potholes

Scaffolding that applies to all examples

Each explanation should include:

●The name of the process involved (erosion and/or the specific type of weathering)

●A drawing that shows the movement of the rock material with arrows (when applicable) and the weathering agent (wind, water, ice)

●A written explanation of what is happening in the drawing

Stages in Your Application Cycle

Stage / Teaching Activities
Establishing the problem / The world is constantly being changed by the processes of weathering and erosion. How can we explain some of the geological features on the surface of the Earth today?
Modeling / We will develop an explanation on the board for the sugar cube demonstration (one of the two PEOE’s).
Coaching / On day 1, each student will write an explanation for the bar of soap example (one of the two PEOE’s). We will write the criteria for a good explanation on the board, and we will walk around answering questions. On day 2, groups will observe different forms of weathering and erosion and write explanations of how they are influencing the material in each model. Again, students will be given our criteria and we will be checking in with the class to make sure they are writing complete responses.
Fading / The students will examine case studies and write explanations using the processes of weathering and erosion to explain the formation of many prominent surface features. The worksheet does not repeat the criteria for each example (only the first one), and we will gradually reduce how often we address the whole class to give reminders.
Maintenance / We did not plan maintenance explicitly into this lesson, but if we can get through all of the examples on day 3 then our fading may lead to maintenance.

C. Lesson Plans

Lesson 1 Materials

Presentation materials (Overhead transparencies or PowerPoint presentations, etc) / Scaffolding criteria written on the board (so that we can use the overhead and still be able to point to the criteria).
Copied materials (Handouts, worksheets, tests, lab directions, etc.) / Lesson 1 worksheet (see Lesson1_WeatheringErosion.docx attached)
Laboratory materials: / (For the teacher or the class as a whole)
- 10 Sugar cubes
- 10 pebbles/rocks
- Jar with lid (tupperware or coffee canister work fine)
-One bar of soap
Other materials: / Weathering and Erosion video from StudyJams:

Rock slide video:

Lesson 1 Activities

Lesson 1 Introduction (10 minutes)

●Establishing the Problem

○We will show a compilation of pictures of interesting land formations from National Geographic’s weathering and erosion photomontage, and then say that the goal for the day is to explain surface features using weathering and erosion.

○On the board, we will have the 3-day lesson’s objective and the day’s activities. We will make the objective clear: “During the next three days, your goal it to be able to explain how weathering and erosion shape Earth’s surface”.

Show video to help students better understand the difference between weathering and erosion and how they work together.

●Weathering and Erosion video from StudyJams:

○

○Review of previous lessons. This should help students review and understand the different vocabulary (mechanical weathering, chemical weathering, erosion) and understand how weathering and erosion are a “superduo” and work together to form Earth’s surface

●Set up the bar of soap PEOE. The Instructor should show students the new bar of soap, and say that you will place it under the faucet for the entire class period, with the faucet dripping very slowly. Ask students to write their prediction of what the soap will look like at the end of the class period, and to explain why. We will return to this at the end of class.

Lesson 1 Main Teaching Activities (30 minutes)

●Modeling

○Materials

■10 Sugar cubes

■10 pebbles

■Jar with lid (tupperware or coffee canister work fine)

○Put 10 sugar cubes and 10 pebbles into the container and put on lid.

●Explain to students that rocks can be broken down when they tumble down a mountain.

○Ask “What causes the rock to first go down the mountain?”

■Students might explain earthquakes, rain, someone pushes it…

■Explain that gravity is always pulling down on us. So yes, rocks can be broken down by weathering and these new fragments of rocks might become unstable and gravity now pulls them down the slope of the mountain.

●Ask “What is another way that rocks can get broken down?”

■Transport in water by rivers and streams. The rocks tumble against each other and get smoothed down.

●We are going to explore what happens as these rocks fall down the mountain by taking some sugar cubes and pebbles and shaking them in this container.

○Explain that the sugar cubes represent a softer rock (like limestone) but we are using sugar cubes in order to see a result in less time.

○Select 2 students to shake the container. (or pass the container around the class?)

●As we are waiting, I want you to predict what is going to happen to the sugar cubes and the rocks and why. We will walk around and check your predictions.

○Select 2 students to replace original volunteers so that they have a chance to write their predictions.

●Show the contents of the tupperware on the overhead. Put the now rounded sugar cube next to an untouched one.

●Ask students to describe their observations. What happened to the sugar cubes?

●Every rock tells a story.

○This activity showed that rocks can be worn down by the direct actions of other rocks.

○What if we kept shaking the container, what might happen (the sugar cubes would become smaller and rounder)? What if we shook it for a few months, a few years (the pebbles would start to break down as well)?

●Model a good response on the overhead (see scaffolding below). Explain the components of our scaffolded response and why we included each part.

○Scaffolding that applies to all examples

■Each explanation should include:

●A drawing that shows the movement of the rock material with arrows (when applicable) and the weathering agent (wind, water, ice)

●The name of the processes involved (erosion and/or the specific type of weathering)

●A written explanation of what is happening in the drawing

●Show this video of a real rock slide (starting at 1 min.).

○Coach a good response on the overhead (see scaffolding above) as a class. Call on students to contribute parts of the response. Encourage class discussion (ex. does anyone disagree?, does anyone want to add something?, can you explain more…?)Make sure students explain the components of our scaffolded response and why we included each part.

Lesson 1 Conclusion (10 minutes)

● Show the bar of soap of the overhead, and ask students to write their observations. Pass the soap around the room as well. Then, ask them to write an explanation of what they observed following the scaffolding criteria on the board. Collect this explanation before they leave.

Lesson 2 Materials

Presentation materials (Overhead transparencies or PowerPoint presentations, etc)
Copied materials (Handouts, worksheets, tests, lab directions, etc.) / Worksheets with lab directions and questions
Laboratory materials:
For the teacher or the class as a whole:
For each laboratory station: / Station 1: tub, sand, water, small pitcher
Station 2: cake pan, cardboard, sand
Station 3:
Ahead of time, the teacher prepares two containers filled with plaster of paris. One with a balloon filled with water (size of a golf ball) and nothing in the other.
At the station: 2 milk cartons (one cracked with remnants of balloon) filled with plaster, explanation of the experiment
Station 4: cake pan, sand, bucket/sink (with filter to collect sand), water, small water pitcher, pipe cleaners
Other materials:

Lesson 2 Introduction (8 minutes)

●Review student responses to the bar of soap example. Go over example responses (one poor, one medium, and one good) and remind the class what constitutes a complete response.