Lesson 2 The Geosphere

Transcription

1 Lesson 2 The Geosphere Student Labs and Activities Page Launch Lab 26 Content Vocabulary 27 Lesson Outline 28 MiniLab 30 Content Practice A 31 Content Practice B 32 Language Arts Support 33 School to Home 35 Key Concept Builders 36 Enrichment 40 Challenge 41 Lab A 44 Lab B 47 Lab C 50 Chapter Key Concepts Builder 51 The Earth System 25

2 Launch Lab LESSON 2: 20 minutes What can you learn from a core sample? Layers of Earth s crust can be studied easily when they are exposed on the side of a cliff. To learn about layers that are buried, however, scientists often drill into the ground to get a core sample. A core sample is a sample of rock and soil taken from inside Earth s upper crust. Procedure 1. Read and complete a lab safety form. 2. Fold a blank sheet of paper into four equal squares. Label the squares A, B, C, and D, respectively. 3. Place thin and thick layers of different-colored salt dough in a bowl. 4. To get core samples, push a clear straw straight down into the clay with a slight twisting motion. Slowly remove the straw. 5. Use scissors to snip off the end of the straw that contains the sample. Place the sample on the paper square labeled A. Write a description of the sample in your Science Journal. 6. Repeat steps 4 and 5 to take core samples B, C, and D from different parts and different depths of the dough crust. Think About This 1. What do the layers of salt dough represent? 2. How are the core samples alike? How are they different? 3. Which layers likely represent the oldest and youngest rock layers in your sample? How do you know? 4. Key Concept Based on your core samples, what can you infer about the materials that make up the upper part of Earth s crust? 26 The Earth System

3 Content Vocabulary LESSON 2 The Geosphere Directions: Explain the differences between the terms in each pair on the lines provided. Use complete sentences. 1. core; crust 2. fracture; cleavage 3. mantle; lithosphere 4. lithosphere; asthenosphere 5. asthenosphere; mantle 6. luster; streak 7. shape; structure The Earth System 27

4 Lesson Outline LESSON 2 The Geosphere A. Materials in the Geosphere 1. are the basic building blocks for soil, rocks, and metals in the geosphere. 2. A mineral is a naturally occurring, solid that has a(n) composition. structure and a definite a. Each mineral has unique properties, some of which can be used to identify a mineral. b. The way the surface of a mineral reflects light is called. c. If you scratch a mineral across a tile, it will leave powder, the color of which is called. d. Minerals are ranked by their relative on Mohs scale. e. The tendency of minerals to break along smooth faces is called. f. The tendency of minerals to break along irregular surfaces is called. 3. form from minerals and other materials. a. There are three main kinds of rocks: rock forms when molten rock cools and hardens; kind of rock is subject to high heat and pressure; forms from layers of tiny rock fragments cemented together. rock forms when any b. Physical and chemical cause rocks to break apart and involve all Earth systems. 4. is the loose, weathered material in which plants grow. a. Soil forms mainly from sediments from that get mixed with years to build up thick rock matter; it takes hundreds or thousands of of soil. 28 The Earth System

5 Lesson Outline continued b. Interactions among all systems occur in soil, and the soil plays important roles in the the cycle. B. Structure of the Geosphere 1. The geosphere has three main layers, which differ by their. Density is a measure of the of the material divided by its volume. cycle and 2. The outermost layer of the geosphere is called the and is formed of rocks. a. crust is formed mainly of the dense igneous rock basalt and gabbro, which have high levels of magnesium. b. crust is made of igneous, metamorphic, and sedimentary rocks that are rich in elements that have a fairly low. and and oxygen c. Continental crust is dense than oceanic crust. 3. The thick, rocky middle layer of the geosphere is called the and, therefore, are ; rocks of the mantle have more iron and magnesium than the rocks of the crust. a. The crust and the uppermost part of the mantle form a brittle outer layer called the. b. Under the lithosphere is a soft layer of partially melted mantle called the. 4. Earth s is the dense, metallic center of Earth. a. The core and the densest layer of the geosphere are made of rather than. b. Earth s outer core is, and its movement as Earth rotates causes a(n) field to form. c. Earth s inner core is mainly due to the pressure of the mass of Earth pushing down on it. The Earth System 29

6 MiniLab LESSON 2: 20 minutes Which mineral is which? Hardness, cleavage, and other properties can be used to distinguish one mineral from another. How can you determine the differences between quartz and calcite? Procedure 1. Read and complete a lab safety form. 2. Determine whether your mineral samples can be scratched by your fingernail and a penny. Record your results in the data table shown in the Data and Observations section below. 3. Examine the samples closely for cleavage planes. Record your observations in the table. 4. Place a few drops of hydrochloric acid on each sample. Record the results. Data and Observations Property Evidence Quartz Calcite Hardness scratches glass yes no scratched by penny scratched by fingernail Cleavage smooth, flat planes visible on surface Reacts with HCl fizzes and produces bubbles Analyze and Conclude 1. Summarize the differences between quartz and calcite. 2. Key Concept Why is calcite more likely to break apart than quartz? 30 The Earth System

7 Content Practice A LESSON 2 The Geosphere Directions: Complete the crossword puzzle with the correct terms from the word bank. asthenosphere cleavage core fracture lithosphere mantle streak Across 1. tendency of minerals to break along smooth, flat surfaces 4. thick, rocky middle layer of the geosphere 6. brittle outer layer formed by the crust and uppermost mantle 7. tendency for minerals to break along irregular surfaces 7 Down 2. weak, partially melted layer of the mantle 3. color of a mineral s powder 5. dense, metallic center of Earth The Earth System 31

8 Content Practice B LESSON 2 The Geosphere Directions: On the line before each statement, write I if the statement is associated with igneous rocks, M if the statement is associated with metamorphic rocks, or S if the statement is associated with sedimentary rocks. 1. The texture of rock is altered. 2. Magma cools and hardens inside Earth. 3. Sediments are eroded and deposited. 4. High temperatures and extreme pressure change rocks. 5. Lava cools and hardens on Earth s surface. 6. Sediments are compacted and compressed. 7. The chemical composition of rock is altered. Directions: Draw and label the layers of the geosphere in the space provided using the correct term from the word bank. crust inner core mantle outer core 32 The Earth System

9 Language Arts Support LESSON 2 Writing Activity: Writing Clear Instructions Learning the Skill Instructions are intended to explain how to do something such as assemble an object, conduct a procedure, or make a cake. Have you ever tried to follow written instructions that are unclear? It can be very difficult to accomplish a task if the instructions do not make sense. Follow the tips below to write clear instructions. Start by writing a statement of the overall purpose of the instructions. Number the steps of the procedure. Use short, direct sentences. Avoid nonspecific words such as this, that, or it. Instead, be specific about the materials involved. Remember that the person using the instructions may be following the process or procedure for the first time. Be thorough in your description. Use plenty of adjectives and exact measurements when it is necessary. Practicing the Skill Directions: Read the instructions below. Then answer each question or respond to each statement on the lines provided. Follow the instructions below to pour a glass of juice: Step 1: Remove the container of juice from the refrigerator. Step 2: Open it. Step 3: Place a 6 8 oz. glass or cup near the container of juice. Step 4: Pour it. Step 5: Replace the lid on the container of juice. Step 6: Return the container of juice to the refrigerator. 1. Which step(s) were least clear? 2. Explain why these step(s) were unclear. 3. Rewrite the step(s) that were unclear to make them clearer. The Earth System 33

10 Language Arts Support LESSON 2 Writing Activity: Writing Clear Instructions Applying the Skill Directions: Galena is a mineral that is gray in color and has a gray streak. It has metallic luster and smooth, flat cleavage planes. Suppose a classmate has an unknown mineral sample. Write instructions that a classmate could use to determine if the sample is the mineral galena. 34 The Earth System

11 School to Home LESSON 2 The Geosphere Directions: Use your textbook to complete the concept map. On the lines beneath each Earth layer, write a definition of the term. In the other boxes, describe the layer. Layers of Earth s Geosphere Mostly oxygen, silicon, and other light elements Includes the asthenosphere a weak, partly melted rock layer Crust Mantle Outer Core Geosphere Inner Core The Earth System 35

12 Key Concept Builder LESSON 2 The Geosphere Key Concept How do materials in the geosphere differ? Directions: Complete the concept map with the correct term or phrase from the word bank. Each term or phrase is used only once. cleavage luster tendency of a mineral to break along irregular surfaces how hard a mineral is streak tendency of a mineral to break along smooth, flat surfaces Mineral Properties way a mineral reflects light color of a mineral s powder hardness fracture 36 The Earth System

13 Key Concept Builder LESSON 2 The Geosphere Key Concept How do materials in the geosphere differ? Directions: On each line, write the term that correctly completes each sentence. 1. A(n) is a naturally occurring, inorganic solid that has a crystal structure and a definite chemical composition. 2. You can observe a mineral s by scratching the mineral across an unglazed porcelain tile. 3. A mineral that breaks with defined edges has. 4. A(n) is a naturally occurring solid composed of minerals and other materials. 5. Igneous rocks form when inside Earth cools and hardens. 6. Metamorphic rocks form when rocks are subjected to high temperatures and extreme. 7. form when sediments are compacted and compressed together. 8. is the loose, weathered material in which plants grow. 9. crust is thinner and denser than crust. 10. The has the largest volume of any layer of Earth. 11. The inner core and outer core are made mainly of. The Earth System 37

14 Key Concept Builder LESSON 2 The Geosphere Key Concept Why does the geosphere have a layered structure? Directions: Label this diagram by writing the correct terms from the word bank on the lines provided. Some terms may be used more than once. Then use the diagram to respond to the statement on the line provided. composed of iron composed of magnesium and iron silicates inner core liquid lower mantle outer core solid upper mantle 670 km below surface ,900 km below surface 5,150 km below surface 6,370 km from surface to center List the layers in order of density beginning with the least-dense layer. 38 The Earth System

15 Key Concept Builder LESSON 2 The Geosphere Key Concept Why does the geosphere have a layered structure? Directions: Answer each question in the space provided. Question Answer 1. What are the three main layers of Earth? 2. Which layer of the geosphere is densest? 3. Which layer of the geosphere is the least dense? 4. When did Earth s layers form? 5. How did the temperature of early Earth affect rocks? 6. Earth s layers can be distinguished by density and what other property? 7. How did the temperature of early Earth compare to Earth s temperature today? 8. What role did gravity have in forming Earth s layered structure? The Earth System 39

16 Enrichment LESSON 2 Sedimentation: From Rock to Rock When any igneous, metamorphic, or sedimentary rock is broken down into particles by physical or chemical weathering, those particles are called sediments. The debris of weathered rocks is constantly being carried away from bedrock by water, ice, and wind. The longer the particles travel and the longer they are in water, the smoother and rounder they become. The material is eventually deposited in places such as lakes, river valleys, and streams. Materials that accumulate as sediments come from two main sources. The first source is solid particles from weathered rocks, and the sedimentary rocks that they form are called detrital sedimentary rocks. The second major source of sediment is soluble material produced mostly by chemical weathering. When dissolved substances are precipitated back as solids, they are called chemical sediment, and they form chemical sedimentary rocks. Detrital Sedimentary Rocks A wide variety of minerals and rock fragments can be found in detrital rocks. Geologists use particle size to distinguish between different types of detrital sedimentary rocks. The size categories are listed in the table. Applying Critical-Thinking Skills Directions: Respond to each statement. Particle-Size Classification for Detrital Rocks Size Range (millimeters) Particle Name more than 256 boulder gravel cobble gravel 4 64 pebble gravel 2 4 granule gravel sand sand less than silt clay Common Sediment Name mud mud Chemical Sedimentary Rocks The sources of chemical sediments are materials that are carried in solution to lakes and seas. These materials, which are dissolved in water, precipitate to form chemical sediments. This precipitation can occur directly through a physical process such as salt left behind as a body of salt water evaporates or indirectly through a biochemical process such as the formation of chalk from the hard parts of microscopic organisms. 1. Hypothesize about the history of the particles in two detrital rocks. The particles in Rock A are rounded, and in Rock B the particles are angular. Explain your answer. 2. Draw a simple sketch of your school, home, or community neighborhood and plot where on the map you can find three of the following sediments: mud, clay, sand, gravel, boulder. Label each location. 40 The Earth System

17 Challenge LESSON 2 Rock History The formation of sedimentary rocks involves interactions among Earth s geosphere, atmosphere, hydrosphere, and biosphere. Weathering breaks rock into small pieces. Weathering occurs when rock is physically broken down as well as from chemical reactions on rock surfaces. Trace the History of a Sedimentary Rock A rock s properties give information about its history. 1. Find an interesting sedimentary rock in your school, home, or neighborhood. It can be natural or human-made. If it is a small, loose rock, bring it to school; if not, write a specific description of its location. 2. Describe the rock in detail and fill out an identification table such as the one below. You might have to do some extra research on the color and composition of the rock. Location Colors All the same color? Minimum grain size cm Maximum grain size cm All the same size? Grain shapes Strength Other comments 3. Hypothesize about where your rock might have originated and how it got to where you found it. Describe your hypothesis in one of the presentations listed below: a map a poem an illustrated time line a television or magazine ad a cartoon a television news report a video clip other product of your choice approved a song by your teacher The Earth System 41

18 Lab A 1 3 class periods Design an Earth-System Game In this chapter, you learned about interactions among the atmosphere, the hydrosphere, the geosphere, and the biosphere. The four systems interact by exchanging matter and energy. Can you design a game that shows the interactions among Earth systems? Question How can a game model interactions among Earth systems? Materials blank index cards glue markers magazines poster board scissors Procedure 1. Read and complete a lab safety form. 2. The object of the game is to collect or earn points for as many different Earth-system interactions as possible. As a group, decide whether to invent an original game or model it after an existing one. 3. You can design a board game or a card game. A board game should have a playing board with interaction squares; playing pieces representing air, water, rock, and a living thing; written instructions. A card game should have two cards each for air, water, rock, and living things; 44 interaction cards (11 for each system). 4. Design and construct your game. Illustrate system interaction squares or cards with drawings, photos, computer graphics, poems, or riddles. 44 The Earth System

19 Lab A continued 5. Write clear directions for your game. Give your game a title. Have your teacher review your game before playing it. 6. Make a copy of the rules for each group member. 7. Read and follow the instructions carefully. Play trial runs of the game with another group. 8. Evaluate the game, and make any necessary improvements. 9. Copy and complete the Game Requirements Checklist. Does your game include all of the required parts? Describe any optional materials that you added to improve the game. Lab Tips Game Requirements Checklist Board Game 1. Illustrated game board 2. Playing pieces: Air, Water, Rock, Living Thing 3. Illustrated system interaction squares 4. Optional chance cards 5. Other optional materials 6. Written instructions Card Game 1. Illustrated Earth-system cards (total: 8) 2. Illustrated Earth-system interaction cards (total: 44) 3. Other optional materials 4. Written instructions Laminate playing cards for durability. Create playing pieces that clearly represent the systems. For example, use a rock to represent the geosphere. The Earth System 45

20 Lab A continued Analyze and Conclude 10. Evaluate Did your game accurately represent Earth systems and their interactions? Use examples to support your answer. 11. Assess What new insights about interactions among Earth systems did you gain by playing the game? 12. The Big Idea Which interactions in the game involved the recycling of Earth materials by Earth systems? Remember to use scientific methods. Make Observations Ask a Question Communicate Your Results Share your game with another group. Play the other group s game. Then, donate your game to the school library so that other classes can play it. Form a Hypothesis Test your Hypothesis Analyze and Conclude Communicate Results 46 The Earth System

21 Lab B 1 3 class periods Design an Earth-System Game In this chapter, you learned about interactions among the atmosphere, the hydrosphere, the geosphere, and the biosphere. The four systems interact by exchanging matter and energy. Can you design a game that shows the interactions among Earth systems? Question How can a game model interactions among Earth systems? Materials blank index cards glue markers magazines poster board scissors Procedure 1. Read and complete a lab safety form. 2. The object of the game is to collect or earn points for as many different Earth-system interactions as possible. As a group, decide whether to invent an original game or model it after an existing one. 3. You can design a board game or a card game. A board game should have a playing board with interaction squares; playing pieces representing air, water, rock, and a living thing; written instructions. A card game should have two cards each for air, water, rock, and living things; 44 interaction cards (11 for each system). 4. Design and construct your game. Illustrate system interaction squares or cards with drawings, photos, computer graphics, poems, or riddles. 5. Write clear directions for your game. Give your game a title. Have your teacher review your game before playing it. 6. Make a copy of the rules for each group member. 7. Read and follow the instructions carefully. Play trial runs of the game with another group. 8. Evaluate the game, and make any necessary improvements. The Earth System 47

22 Lab B continued 9. Copy and complete the Game Requirements Checklist. Does your game include all of the required parts? Describe any optional materials that you added to improve the game. Game Requirements Checklist Board Game 1. Illustrated game board 2. Playing pieces: Air, Water, Rock, Living Thing 3. Illustrated system interaction squares 4. Optional chance cards 5. Other optional materials 6. Written instructions Card Game 1. Illustrated Earth-system cards (total: 8) 2. Illustrated Earth-system interaction cards (total: 44) 3. Other optional materials 4. Written instructions Lab Tips Laminate playing cards for durability. Create playing pieces that clearly represent the systems. For example, use a rock to represent the geosphere. Analyze and Conclude 10. Evaluate Did your game accurately represent Earth systems and their interactions? Use examples to support your answer. 48 The Earth System

23 Lab B continued 11. Assess What new insights about interactions among Earth systems did you gain by playing the game? 12. The Big Idea Which interactions in the game involved the recycling of Earth materials by Earth systems? Communicate Your Results Share your game with another group. Play the other group s game. Then, donate your game to the school library so that other classes can play it. Remember to use scientific methods. Make Observations Ask a Question Form a Hypothesis Extension Test your Hypothesis Analyze and Conclude Communicate Results Select a location outside your school or home. Observe and record Earth-system interactions. Take photos, if possible, or sketch the interactions. Work with other students to create a classroom display of Earth-system interactions. The Earth System 49

24 Lab C Human Influences on Earth Systems Directions: Use the information and data from the Lab Design an Earth-System Game to perform this lab. You have learned that interactions occur between Earth s hydrosphere, atmosphere, biosphere, and geosphere. In Lab B, you investigated these interactions by making a game that shows how these systems interact. Consider the effects of human influence on these interactions by adding human activities and possible effects, both positive and negative, to your game. Please note that you must complete Lab B before beginning Lab C. Also, have your teacher approve your design and safety procedures before beginning your experiment. 50 The Earth System

25 Chapter Key Concepts Builder The Earth System End-of-Chapter Practice Directions: Work with a group to design a field guide for minerals. A field guide is a book that contains information about a particular subject, such as birds, trees, or minerals. To design and create your field guide for minerals, first gather information about minerals. Which mineral properties should we test? Which materials will we need to conduct the tests? Who will conduct each test? Complete your tests. Then share your results with your group. Next, brainstorm your design. Consider the following issues: What information should be included in the field guide? How should we arrange the information? Share your design with the class. Ask for feedback from class members. Use the feedback to improve your design. Then create your field guide. Make copies for the classroom and the school library. Field Guide requirements: based on results from mineral tests organized in a logical manner includes title page, table of contents, glossary, and index includes contributions from all group members The Earth System 51