Lesson 3 The Theory of Tectonics LA.7.2.2.3, MA.6.A.3.6, SC.7.E.6.4, SC.7.E.6.5, SC.7.E.6.7, SC.7.N.1.1, SC.7.N.1.5, SC.7.N.1.6 Skim or scan the heading, boldfaced words, and pictures in the lesson. Identify or predict three facts you will learn from the lesson. Discuss your thoughts with a classmate. The Tectonics Theory I found this on page. State the problem that scientists had with seafloor spreading. I found this on page. Define plate tectonics. Explain what the word tectonic means as part of your definition. Benchmark Practice Chapter Review Study Guide I found this on page. Boundaries NGSSS Check What are the three types of plate boundaries? SC.7.E.6.5 Identify the layers of Earth involved in plate movements. Describe how these layers interact. Layer Asthenosphere Description consists of the crust and the solid, uppermost mantle Organize information about divergent plate boundaries. Use arrows to show how plates move relative to one another at this type of boundary. Type of Boundary Divergent Description Movement 134 Tectonics
Lesson 3 The Theory of Tectonics (continued) I found this on page. Model transform plate boundaries. Either write a description or illustrate this type of plate interaction. Include arrows to show the direction of movement. Label the plates and the structures that result from the collisions. I found this on page. Transform Boundaries Continent-to-Continent Collision Study Guide Chapter Review Benchmark Practice Tectonics 135
Lesson 3 The Theory of Tectonics (continued) Evidence for Tectonics I found this on page. Identify evidence for plate motion provided by plate tectonics. 1. 2. 3. 4. Motion I found this on page. Define convection, and give an example of convection you have experienced in your everyday life. Definition: Benchmark Practice Chapter Review Study Guide I found this on page. Example: Explain how convection occurs in the mantle by completing the sequence diagram. The elements heat the inside of Earth. is transferred from the to the. currents form. These currents in the asthenosphere move the above it. In this way, move in response to. 136 Tectonics
Lesson 3 The Theory of Tectonics (continued) I found this on page. Describe the forces that cause plate motion. Force Basal drag Description Ridge push A Theory in Progress I found this on page. Slab pull Identify four questions scientists have about plate tectonics. 1. 2. 3. 4. What explanation can you offer for several volcanoes located in a line on the seafloor erupting over time to form islands? Study Guide Chapter Review Benchmark Practice Tectonics 137
Review Tectonics Chapter Wrap-Up Now that you have read the chapter, think about what you have learned. Use this checklist to help you study. Complete your Foldables Chapter Project. Study this chapter in your Notebook. Study the definitions of vocabulary words. Reread the chapter, and review the charts, graphs, and illustrations. Review the Understanding Key Concepts at the end of each lesson. Look over the Chapter Review at the end of the chapter. THINK ABOUT IT! Summarize It Reread the Think About It question and the lesson Key Concepts. Draw a world map showing how the continents might be arranged 100 million years from now. Label the landmasses on your map, and explain why you positioned them in the way that you did. Benchmark Practice Chapter Review Study Guide Challenge Suppose that you are designing a new scientific instrument to record or measure some geological data that previously could not be observed. Describe what your new super-technology could detect and how those discoveries might solve remaining mysteries of plate tectonics. 138 Tectonics
6 Earth Structures Movement of Boundaries SC.7.E.6.4 Earth s surface is broken into 12 major tectonic plates. Wherever these plates touch, one of four things occurs. The plates might collide and crumple or fold, making mountains. One plate might subduct under another, forming volcanoes. They might move apart and form a mid-ocean ridge, or they may slide past each other, causing an earthquake. This investigation models plate movements. Question What happens where two plates come together? Materials graham crackers waxed paper (four 10-cm 10-cm squares) dropper frosting plastic spoon Safety Procedure Part I 1. Read and complete a lab safety form. 2. Obtain the materials from your teacher. 3. Break a graham cracker along the perforation line into two pieces. 4. Lay the pieces side by side on a piece of waxed paper. 5. Slide crackers in opposite directions so that the edges of the crackers rub together. Part II 6. Place two new graham crackers side by side but not touching. 7. In the space between the crackers, add several drops of water. 8. Slide the crackers toward each other and observe what happens. Part III 9. Place a spoonful of frosting on the waxed-paper square. 10. Place two graham crackers on top of the frosting so that they touch. 11. Push the crackers down and spread them apart in one motion. Lab Tips Use fresh graham crackers. Slightly heat frosting to make more fluid for experiments. Study Guide Chapter Review Benchmark Practice Tectonics 139
Big Idea Lab continued Analyze and Conclude Part I 12. Analyze the movement of the crackers in each of your models. 13. What type of plate boundary do the crackers in this model represent? 14. What do the crumbs in the model represent? 15. Did you feel or hear anything when the crackers moved past each other? Explain. 16. How does this model simulate an earthquake? Benchmark Practice Chapter Review Study Guide Part II 17. What does the water in this model represent? 18. What type of plate boundary do the graham crackers in this model represent? 19. Why didn t one graham cracker slide beneath the other in this model? Part III 20. What type of plate boundary do the graham crackers in this model represent? 21. What does the frosting represent? 140 Tectonics
Big Idea Lab continued 22. What shape does the frosting create when the crackers move? 23. What is the formation formed from the crackers and frosting? Communicate Your Results Create a flip book of one of the boundaries to show a classmate who was absent. Show how each boundary plate moves and the results of those movements. Remember to use scientific methods. Make Observations Ask a Question Form a Hypothesis Test your Hypothesis Analyze and Conclude Communicate Results Extension Place a graham cracker and a piece of cardboard side by side. Slide the two pieces toward each other. What type of plate boundary does this model represent? How is this model different from the three that you observed in the lab? Study Guide Chapter Review Benchmark Practice Tectonics 141
Big Idea Lab Notes Benchmark Practice Chapter Review Study Guide 142 Tectonics
Study Guide Use Vocabulary Use vocabulary terms from the chapter to complete the sentences and answer the questions below. 1. The process in which hot mantle rises and cold mantle sinks is called. 2. What is the plate tectonics theory? 3. What was Pangaea? 4. Identify the three types of plate boundaries and the relative motion associated with each type. 5. Magnetic reversals occur when. 6. Explain seafloor spreading in your own words. Link Vocabulary and Key Concepts Use vocabulary terms from the chapter to complete the concept map below. 7. 8. 9. 10. magnetic data on seafloor mantle convection evidence from forces Tectonics boundary types 13. explains location of 14. 12. 11. transform mountains Study Guide Chapter Review Benchmark Practice Tectonics 143
Chapter 4 Review Understand Key Concepts Circle the correct answer below. 1. Alfred Wegener proposed the hypothesis. SC.7.E.6.5 A. continental drift B. plate tectonics C. ridge push D. seafloor spreading 2. Ocean crust is SC.7.E.6.5 5. Mid-ocean ridges are associated with SC.7.E.6.5 A. convergent plate boundaries. B. divergent plate boundaries. C. hotspots. D. transform plate boundaries. 6. Two plates of equal density form mountain ranges along SC.7.E.6.5 A. continent-to-continent convergent boundaries. B. ocean-to-continent convergent boundaries. C. divergent boundaries. D. transform boundaries. Benchmark Practice Chapter Review Study Guide A. made from submerged continents. B. magnetically produced crust. C. produced at the mid-ocean ridge. D. produced at all plate boundaries. 3. What technologies did scientists NOT use to develop the theory of seafloor spreading? SC.7.N.1.6 A. echo-sounding measurements B. GPS (global positioning system) C. magnetometer measurements D. seafloor thickness measurements 4. The picture below shows Pangaea s position on Earth approximately 280 million years ago. Where did geologists discover glacial features associated with a cooler climate? SC.7.E.6.4 A. Antarctica B. Asia C. North America D. South America Pangaea 7. Which type of plate boundary is shown in the figure below? SC.7.E.6.5 A. convergent boundary B. divergent boundary C. subduction zone D. transform boundary 8. What happens to Earth s magnetic field over time? SC.7.E.6.4 A. It changes polarity. B. It continually strengthens. C. It stays the same. D. It weakens and eventually disappears. 9. Which of Earth s outermost layers includes the crust and the upper mantle? SC.7.E.6.1 A. asthenosphere B. lithosphere C. mantle D. outer core 144 Tectonics
Chapter 4 Review continued Critical Thinking Use the lines below to respond to the following questions. 10. Evaluate The oldest seafloor in the Atlantic Ocean is located closest to the edge of continents, as shown in the image below. Explain how this age can be used to figure out when North America first began to separate from Europe. SC.7.E.6.5 Pangaea 11. Examine the evidence used to develop the theory of plate tectonics. How has new technology strengthened the theory? SC.7.N.1.5 12. Explain Sediments deposited by glaciers in Africa are surprising because Africa is now warm. How does the hypothesis of continental drift explain these deposits? SC.7.E.6.4 Study Guide Chapter Review Benchmark Practice Tectonics 145
Chapter 4 Review continued Critical Thinking Use the lines below to respond to the following questions. 13. Draw a diagram to show subduction of an oceanic plate beneath a continental plate along a convergent plate boundary. Explain why volcanoes form along this type of plate boundary. SC.7.E.6.5 Benchmark Practice Chapter Review Study Guide 14. Infer Warm peanut butter is easier to spread than cold peanut butter. How does knowing this help you understand why the mantle is able to deform in a plastic manner? SC.7.E.6.7 146 Tectonics
Chapter 4 Review continued 15. Predict If continents continue to move in the same direction over the next 200 million years, how might the appearance of landmasses change? Write a paragraph to explain the possible positions of landmasses in the future. Based on your understanding of the plate tectonic theory, is it possible that new supercontinents will form in the future? SC.7.E.6.7 Study Guide Chapter Review Benchmark Practice Tectonics 147
Chapter 4 Review continued Review the Big Idea 16. What is the theory of plate tectonics? Distinguish between continental drift, seafloor spreading, and plate tectonics. What evidence was used to support the theory of plate tectonics? SC.7.E.6.5 Benchmark Practice Chapter Review Study Guide 17. Use the image on page 143 of your textbook to interpret how the theory of plate tectonics helps to explain formation of huge mountains like the Himalaya. SC.7.E.6.5 Math Skills Use Proportions MA.6.A.3.6 18. Mountains on a convergent plate boundary may grow at a rate of 3 mm/y. How long would it take a mountain to grow to a height of 3,000 m? (1 m = 1,000 mm) 19. The North American and the Pacific have been sliding horizontally past each other along the San Andreas fault zone for about 10 million years. The plates move at an average rate of about 5 cm/y. a. How far have the plates traveled, assuming a constant rate, during this time? b. How far has the plate traveled in kilometers? (1 km = 100,000 cm) 148 Tectonics
Name Date Class Science Benchmark Practice Mark your answer in the answer bubbles below each question. Multiple Choice Use the diagram below to answer questions 1 and 2. Caribbean Arabian African Scotia Antarctic B island chain C mid-ocean ridge D polar axis 2 What do the arrows indicate? F magnetic polarity G ocean flow H plate movement I volcanic eruption deduction H induction I subduction 5 What causes plate motion? SC.7.E.6.7 A convection in Earth s mantle B currents in Earth s oceans C reversal of Earth s polarity D rotation on Earth s axis 6 Ocean basins will expand as new oceanic crust forms and moves away from a midocean ridge during SC.7.E.6.7 F continental drift. G magnetic reversal. H normal polarity. I seafloor spreading. Use the diagram below to answer question 7. SC.7.E.6.5 3 What evidence helped to support the theory of seafloor spreading? SC.7.E.6.5 Chapter Review Pangaea 7 What is the name of Alfred Wegener s ancient supercontinent pictured in the diagram above? SC.7.E.6.5 A magnetic equality B magnetic interference C magnetic north A Caledonia D magnetic polarity B continental drift C Glossopteris D Pangaea Tectonics Benchmark Practice abyssal plain G Study Guide A conduction 1 In the diagram above, what does the irregular line between tectonic plates represent? SC.7.E.6.5 F South American 4 Which plate tectonic process creates a deep ocean trench? SC.7.E.6.5 149
NGSSS for Science Benchmark Practice continued Use the diagram below to answer question 8. 1 2 3 4 5 Oceanic crust Mid-ocean ridge 11 What is the dominant type of rock formed at mid-ocean ridges? SC.7.E.6.2 A granite B basalt C sediment D sedimentary rock Asthenosphere Magma Asthenosphere Use the diagram below to answer questions 12 and 13. Benchmark Practice Chapter Review Study Guide 8 The numbers in the diagram represent seafloor rock. Which represent the oldest rock? SC.7.E.6.5 F 1 and 5 G 2 and 4 H 3 and 4 I 4 and 5 9 Which part of the ocean basin contains the thickest sediment layer? SC.7.E.6.2 A abyssal plain B deposition band C mid-ocean ridge D tectonic zone 10 What type of rock forms when lava cools and crystallizes on the seafloor? SC.7.E.6.2 F a fossil G a glacier H basalt I magma 12 According to the theory of plate tectonics, what is the source of the force that causes the plates to move? SC.7.E.6.7 F convection currents G magnetic reversal H normal polarity I ridge push 13 What is the energy source that powers plate movement? SC.7.E.6.7 A slab pull B less dense continents C magma and lava D Earth s hot interior 150 Tectonics
Benchmark Mini-Assessment Chapter 4 Lesson 1 Multiple Choice Bubble the correct answer. Greenland Caledonian Mountains North America Appalachian Mountains British Isles Scandinavia Eurasia Africa South America Africa India Antarctica 1. In the image above, what suggests that North America and Europe once were connected? SC.7.E.6.4 A The continents have the same fossils. B The continents share the same year-round climate. C The Appalachian and Caledonian mountain ranges connect. D The rocks from the British Isles also exist in North America. 2. One continental portion of Pangaea became part of Asia. Which subcontinent joined Asia during the breakup of Pangaea? SC.7.E.6.4 F Africa G Australia H Europe I India Australia 3. What is happening in the image above? SC.7.E.6.5 A climate changes B continental drift C fossil formation D glacial movement 4. According to Wegener s theory, in which direction did the North American continental mass move? SC.7.E.6.4 F northeast G northwest H due north I due west Extend Your Learning Turn the page to Learn Out Loud Study Guide Chapter Review Benchmark Practice Tectonics 151
Think, Discuss, Share Benchmark Practice Chapter Review Study Guide From My Teacher 152 Tectonics
Benchmark Mini-Assessment Chapter 4 Lesson 2 Multiple Choice Bubble the correct answer. Use the illustration below to answer questions 1 3. L M N O P 3. At which point is the lithosphere the thinnest? SC.7.E.6.4 A M B N C O D P 4. What evidence was found to support the theory of seafloor spreading? SC.7.E.6.5 1. At which point in the ocean-floor diagram above will the oldest rock be found? SC.7.E.6.3 A L B M C N D O 2. At what point will sediment have made the seafloor smoothest? SC.7.E.6.7 F L G N H O I P F Earth s magnetic field has reversed direction many times. G Earth s magnetic field has stayed the same for hundreds of years. H More heat is released from beneath the abyssal plains than near mid-ocean ridges. I The iron-rich minerals found on the seafloor have proved not to be magnetic. Extend Your Learning Turn the page to Learn Out Loud Study Guide Chapter Review Benchmark Practice Tectonics 153
Think, Discuss, Share Benchmark Practice Chapter Review Study Guide From My Teacher 154 Tectonics
Name Date Benchmark Mini-Assessment Class Chapter 1 Lesson 3 Multiple Choice Bubble the correct answer. 3. Which image shows a transform plate boundary? SC.7.E.6.5 Use the illustration below to answer questions 1 and 2. North American Juan Caribbean de Fuca Cocos Pacific Nazca South American Scotia North American Eurasian Arabian Mid-ocean ridge Oceanic crust Philippine Pacific African Indo-Australian Antarctic Rift valley Divergent boundary Convergent boundary boundary A Lithosphere Asthenosphere 1. At the boundaries of which plates would you expect to find volcanoes? SC.7.E.6.5 A African and Arabian s B Eurasian and Indo-Australian s C North American and Caribbean s B Continental crust Continental crust D Pacific and Nazca s Lithosphere African and South American s Deep ocean trench G Eurasian and African s Volcanoes Oceanic crust H Eurasian and Indo-Australian s I Nazca and South American s C Lithosphere Continental crust Study Guide Asthenosphere Mountains Chapter Review D Continental crust Lithosphere Asthenosphere Benchmark Practice F 2. At the boundaries of which plates would you expect to find a rift? SC.7.E.6.5 Extend Your Learning Turn the page to Learn Out Loud Tectonics 155
Think, Discuss, Share Benchmark Practice Chapter Review Study Guide From My Teacher 156 Tectonics
Notes Study Guide Chapter Review Benchmark Practice Earth Dynamics 157