TITLE OF LESSON PLAN: Rocks

Transcription

1 TITLE OF LESSON PLAN: Rocks LENGTH OF LESSON: One class period GRADE LEVEL: 6-8 SUBJECT AREA: Earth Science CREDIT: Betsy Hedberg, former middle school teacher and current freelance curriculum writer and consultant. OBJECTIVES: Students will understand the following: 1. Old rocks on Earth's surface are gradually reduced to tiny pieces, or sediments, by erosion caused by water, wind, or glacial ice. 2. Sedimentary rock is formed when those small pieces of rock are compressed into larger rock formations. 3. Erosion breaks the rock down again, and the cycle continues. MATERIALS: For this lesson, you will need: Research materials on rock formation and different types of rock Computer with Internet access

2 PROCEDURE: 1. Review with your students what they know about the three types of rock sedimentary, igneous, and metamorphic. 2. Tell them that they are going to write children's stories to explain to younger students how sedimentary rock is formed. 3. Suggest they create characters that are tiny pieces of rock or grains of sand. The plot should illustrate the process by which tiny rock fragments are deposited into riverbeds, seas, or deserts and compressed to form layers of sedimentary rock. 4. Encourage students to do research about sedimentary rock and the rock cycle before they begin their stories, to be sure they do not convey any incorrect information to younger readers. 5. Instruct students that their stories should dramatize their understanding of the rock cycle and should be illustrated with diagrams that clearly show the cycle's different stages. Students should include decorative illustrations as well. ADAPTATIONS: Adaptations for Older Students: Have students use the Internet and other research materials to find out about the Mohs scratch test and how it is used to identify different types of rock. Students can then collect rock samples and use the Mohs test to classify and label their samples. They should use a field guide to check their identifications.

3 DISCUSSION QUESTIONS: 1. Have you noticed the effects of erosion on any rock formations that you've seen, either near your home or elsewhere? Discuss the places where you've noticed erosion, and speculate about the causes for that erosion. 2. Compare the geology of your home to one of the well-known regions of the country that has distinct types of rock formations, such as northern Arizona (where the Grand Canyon is located) and Hawaii (volcanic islands). How were the rock formations in each place created, and what are the main differences between them? 3. Why do you think geologists are eager to study the processes involved in creating and changing rock formations? Explain what useful knowledge can be gained from studying rocks and rock formations. EVALUATION: You can evaluate your students on their stories and illustrations using the following threepoint rubric: Three points:story imaginative and creative; story accurately and clearly explains the rock cycle; diagrams and illustrations clearly show the cycle's different stages Two points:story lacking in imagination and creativity; story adequately explains the rock cycle; diagrams and illustrations show some of the cycle's stages One point:story lacking in imagination and creativity; rock cycle inadequately explained; diagrams and illustrations unclear or entirely lacking You can ask your students to contribute to the assessment rubric by determining which stages of the rock cycle should be explained and illustrated. EXTENSION: Investigating Local Geology Have students investigate what types of rocks and rock formations are common in their home region. They can find this information in the library, on the Internet, or from knowledgeable people in the community. Then ask them to spend some time over a weekend taking photographs or drawing pictures of nearby rock formations. Once they get back to the classroom, ask them to determine, to the best of their ability, what types of rocks they have photographed or illustrated. Have them conduct further research to learn

4 how those formations were most likely created; then ask them to write captions describing their pictures. You can conclude by having your students combine their pictures into a Local Geology Portfolio, which can take the form of a poster, booklet, or multimedia presentation. Rock Hunt Take your class on a field trip to find examples of different kinds of rock used for practical purposes. Look at buildings and monuments for blocks of the igneous rock granite, the sedimentary rock sandstone(or brownstone), and the metamorphic rock slate. Look at museums and public buildings for examples of the metamorphic rock marble, used in many floors, monuments, and statues. Chalk, a type of limestone (sedimentary), and slate can be found right in your classroom. Have students make a chart to record the kinds of rock they saw, where they saw them, and for what purposes they were used. SUGGESTED READINGS: Discover Nature in the Rocks: Things to Know and Things to Do Rebecca Lawton, Diana Lawton, and Susan Panttaja. Stackpole Books, Making rice treats as an example of conglomerate rocks and rubbing and freezing rocks to illustrate the effects of erosion are just two of the fascinating experiments contained in this book, all of which help bring geology to life. The glossary, bibliography, and many line drawings enhance the very readable text. The Smithsonian Guides to Natural America: The Southwest Jake Page. Smithsonian Books, Spectacular photos illustrate the variety of geological formations found in New Mexico and Arizona while landform maps assist in locating them. WEB LINKS: Geology Tour of the Solar System A fascinating site that allows one to compare and contrast geologic features as they exist on different planetary bodies Nevada Mining Association This site features a fun geology project each month like chocolate chip mining or peanut butter and jam geology and is a great resource for teachers.

5 Rocks and Mineral Slide Show Part of the famous Volcano World site, this page provides a great resource for rocks and minerals with clear pictures and descriptions Bob's Rock Shop A non-commercial online site that is in partnership with Gems and Minerals Magazine. The site is for rock collecters and provides a nice selection of rocks and minerals on display. Chamber of Mines of South Africa This site provides a comprehensive history of gold for students. VOCABULARY: erosion The action or process of wearing away by the action of water, wind, or glacial ice. Wind, water, or ice can cause erosion of sedimentary rock, resulting in some of the rock being broken down into smaller pieces and carried away. igneous Relating to, resulting from, or suggestive of the intrusion or extrusion of magma or volcanic activity; formed by solidification of magma. After a volcanic eruption, lava cools and forms igneous rock. metamorphic Of or relating to a change of physical form, structure, or substance. Metamorphic rock is formed when sedimentary or igneous rock is exposed to high heat and pressure, thus transforming the rock. sedimentary Formed by or from material transported and deposited by water, wind, or glaciers, or by the secretions of organisms. Sedimentary rock is created when small pieces of rock are deposited and compressed into larger rock formations.

6 ACADEMIC STANDARDS: Grade Level: 3-5, 6-8 Subject Area: science: Earth and space Standard: Understands basic Earth processes. Benchmarks: Benchmark 3-5: Knows that smaller rocks come from the breakage and weathering of bedrock and larger rocks. Benchmark 3-5: Knows how features on the Earth's surface are constantly changed by a combination of slow and rapid processes (e.g., weathering, erosion, and deposition of sediment caused by waves, wind, water, and ice; sudden changes in the landscape caused by landslides, volcanic eruptions, and earthquakes). Benchmark 3-5: Knows that fossils provide evidence about the plants and animals that lived long ago and the nature of the environment at that time. Benchmark 6-8: Knows that sedimentary, igneous, and metamorphic rocks contain evidence of the minerals, temperatures, and forces that created them. Benchmark 6-8: Knows processes involved in the rock cycle (e.g., old rocks at the surface gradually weather and form sediments that are buried, then compacted, heated, and often recrystallized into new rock; this new rock is eventually brought to the surface by the forces that drive plate motions, and the rock cycle continues). DiscoverySchool.com Copyright 2001 Discovery.com. Teachers may reproduce copies of these materials for classroom use only.