The Theory of Plate Tectonics Name

The Theory of Plate Tectonics Name Intermediate Version Block CHAPTER 1 INTRODUCTION 1. The scientific theory that describes the movement of Earth s outer layer is called. CHAPTER 2 CONTINENTAL DRIFT: AN IDEA BEFORE ITS TIME 2. The hypothesis that states that the continents drift about is called and was proposed by a German scientist named. 3. He proposed that a supercontinent named existed over 200 million years ago (mya). The supercontinent began to break into smaller continents which drifted apart about 180 mya. FIT OF THE CONTINENTS 4. Alfred Wegener first thought the continents might have been joined when he noticed the similarities between coastlines of South America and. FOSSIL EVIDENCE 5. Fossils of, a reptile that existed 240 mya, are found in both South America and Africa. 6. Fossils of, a land reptile that existed 240 mya, are found in Africa, India and the Antarctic. 7. Evidence of, a plant that existed 260 mya, appears in all of these continents. 8. Fossils of, a swimming reptile that existed 260 mya, are found in both South America and Africa. 9. Click on the clock (Geologic Time Scale) and shovel (fossils found in North and South America) for further information. Record one point of interest for each topic. Geologic Time Scale Fossils found in North and South America

2 EVIDENCE FROM ROCKS 10. The Appalachian Mountains along the eastern coast of North America disappear off the coast of. 11. Mountains of the same age and structure are found in the and Scandinavia. PALEOCLIMATIC EVIDENCE 12. Vast ice sheets covered the Southern Hemisphere about 250 mya. The glaciated area in extends into the equatorial region. (Refer to map for answer.) 13. During the same period of time, large tropical swamps existed in the Northern Hemisphere. These became the major fields of the USA, Europe and Asia. 14. The areas containing these ancient landscapes must have been joined together in the supercontinent of and located far south of their present positions. REVIEW: THE GREAT DEBATE 1. What was Pangaea? 2. When did Pangaea exist? 3. Who proposed the continental drift hypothesis? 4. Evidence that Wegener used to support his hypothesis: (4 points) 5. True or False: Wegener's hypothesis was accepted. 6. One reason Wegener's hypothesis was rejected was: 7. Why was a major cooling period ruled out as a reason for glaciation in Australia? 8. Why didn't Mesosaurus swim freely from South America to Africa?

3 CHAPTER 3 EXPLORING CONTINENTAL DRIFT REVIEW: APPLYING THE EVIDENCE Name of your planet: REVIEW: A CLOSER LOOK 1. Rotate the Earth to 150 degrees west longitude. What lies opposite of Pangaea? 2. True or False: The North Atlantic opened before South Atlantic. 3. When did the opening of the North Atlantic Ocean occur? 4. When did South America completely separate from Africa? 5. India's path during the last 100 million years: 6. Africa's direction during the last 100 million years: 7. During the last 20 million years, what sea formed between Africa and the Arabian Peninsula? 8. What is the name of the chain of islands in the Pacific Ocean? 9. When did the first islands form in this chain? 10. Where was Australia located 135 million years ago? 11. When did North and South America rejoin? CHAPTER 4 EARTH S INTERIOR 15. The four major layers of the earth are the: - solid nickel and iron. - a fluid metallic layer which generates Earth s magnetic field. - a dense rocky, layer that contains silicate minerals which are rich in iron and magnesium. CRUST - a thin outer skin which is made of two parts; the crust (which is composed of a dark igneous rock called basalt) and the crust (which is composed of the lighter and less dense igneous rock granite). 16. A hot weak zone of the upper mantle is called the. 17. The solid portion of earth above this layer is called the and consists of the crust and the rigid upper most part of the mantle.

4 18. The weak rock within the allows Earth s rigid outer shell ( ) to move. CHAPTER 5 NEW EVIDENCE: MAPPING THE OCEAN FLOOR 19. Most of the scientific community did not support Wegener s continental drift hypothesis for at least 50 years. Improvement in technology permitted mapping of the ocean floor. 20. Based on these studies the floor of the ocean is divided into three broad zones: The, the and the. 21. The is considered a flooded extension of the continent. 22. The is the seaward edge of the continental shelf. 23. Many deep-ocean parallel the continental shelves along the margin of the Pacific Ocean. 24. Ocean basins are characterized by large flat areas buried in layers of and submerged volcanic peaks called. 25. The longest topographic feature on Earth s surface is the system. The summit of the oceanic ridge usually has a deep, narrow valley called a valley. 26. Volcanic activity and geyser like features called are also commonly associated with the ridge system. CHAPTER 6 PLATE TECTONICS: A SCIENTIFIC REVOLUTION UNFOLDS 27. By 1968 additional discoveries led to a more encompassing theory known as. 28. This theory holds that the crust consists of numerous segments called. 29. Some of the plates are composed mostly of oceanic crust while others consist of both continents and ocean basins. These plates tend to be than the oceanic plates. 30. According to the plate tectonic model each plate moves as a distinct unit. The distances between locations on the same plate remain, while the distances between locations on plates are constantly changing.

5 31. Because each plate moves as a unit all major interactions between plates occur along their. 32. The three major types of boundaries are: Boundaries - which move apart Boundaries - which move together Faults or Boundaries - which slide past each other 33. Refer to Slide #172. Record the names of these plates on the diagram below. A African B Eurasian C Australian-Indian D South American E Caribbean F Nazca G Pacific H Juan de Fuca I North American J Philippine K Coco L Scotia M Antarctic CHAPTER 7 DIVERGENT PLATE BOUNDARIES (REVIEW) 34. Plates are moving apart at boundaries. 35. At divergent plate boundaries new is forming. 36. New oceanic crust is created at a rate of centimeters per year. 37. Most divergent boundaries are located along.

6 38. Which of these water bodies was once a rift valley? 39. As plates move apart, the gap between them is filled with molten rock called. 40. The mechanism that has generated the floors of the world's oceans is called. 41. When divergent plate boundaries continue to operate within a continent, the landmass may develop a and split into two smaller continents. CHAPTER 8 CONVERGENT BOUNDARIES (REVIEW) 42. At convergent plate boundaries old lithosphere is being. 43. The region where oceanic lithosphere descends into the asthenosphere is called a zone. 44. Convergent plate margins occur where two plates are moving toward one another and the movement is accommodated by one plate beneath the other. 45. Whenever a slab of oceanic lithosphere converges with a slab of continental lithosphere the oceanic descends into the. 46. What is the main factor that triggers the formation of magma during subduction? 47. Volcanoes associated with continental volcanic arcs generally erupt. 48. The Andes and Cascades exemplify these features: 49. The Aleutian Islands, Tonga Islands, and Japan are examples of: 50. Most volcanic island arcs are located near 51. Most volcanic island arcs are located in the: 52. Which of these mountain belts formed by continental collisions? 53. TRUE or FALSE: Collision mountain belts form because continental crust is too buoyant to undergo appreciable subduction, and results in a collision between continental fragments.

CHAPTER 9 TRANSFORM FAULT BOUNDARIES (REVIEW) 54. Which of these are true about transform faults: (Check all that apply.) plates slide horizontally past each other most join two segments of the oceanic ridge system sometimes connect convergent and divergent plate boundaries 55. Which arrows indicate the direction of fault motion? 56. TRUE or FALSE: Great earthquakes can be generated at transform boundaries. 57. Which are characteristics of the San Andreas Fault? (Check all that apply.) produces offset stream channels it is a transform fault generates great earthquakes 58. TRUE or FALSE: Along the San Andreas Fault, the Pacific plate is moving toward the northwest, relative to the North American plate. CHAPTER 10 A CLOSER LOOK AT PLATE BOUNDARIES (REVIEW) PRINT YOUR SCORE SHEET AND ATTACH IT TO THIS PACKAGE. 7 CHAPTER 11 TESTING THE PLATE TECTONICS MODEL EARTHQUAKE PATTERNS 42. Which of type of seismic waves travel the fastest? 43. Which seismic waves travel the slowest? 44. Compare the seismograms. Which city is located farthest from the epicenter? How many minutes separate the arrival of the first P wave and the first S wave for this location? minutes When the first P wave arrives 4 minutes before the S wave, the distance from the recording station was km How far is the epicenter from a recording station located in Nagpur, India? km Darwin, Australia? km Paris, France? km

8 45. There is a close association between the distribution of earthquakes and. 46. Earthquakes are thought to be generated within the. 47. TRUE or FALSE: Earthquakes occur in the lithosphere because it is able to store elastic energy like a stretched rubber band. 48. Energy released by an earthquake travels in the form of. 49. The source of an earthquake is called the. 50. The location at the surface directly above the source of an earthquake is called the. 51. The instrument used to record seismic waves is called a. 52. Most earthquakes occur in a region known as the. 53. Plate Tectonics seems to account for the close association between deep-focus earthquakes and trenches. 54. Shallow focus earthquakes are produced as the descending plate is bent and interacts with the overriding plate. As the cold, rigid slab descends further into the asthenosphere deeper earthquakes are generated. These earthquakes occur within the plate rather than within the hot asthenosphere and allow scientists to track the plate s descent. Shallow focus earthquakes also occur along the oceanic ridge system where sea-floor spreading is occurring. 55. The only places where cold slabs of oceanic crust reach the great depths of the deepfocus earthquakes are the zones of convergent boundaries. The absence of deep-focus earthquakes along spreading centers and transform faults supports the Theory of Plate Tectonics. HOT SPOTS AND MANTLE PLUMES 56. Scientific dating of the Hawaiian chain of volcanic structures, which extend from the Hawaiian Islands to the Aleutian Trench, indicated that the volcanoes get older with increasing distance from Hawaii. This chain of progressively older volcanoes is the result of the Pacific Plate moving over a stationary rising plume or. 57. Five mya the island of Kauai rather than Hawaii was located over this. At that point it was the ONLY Hawaiian Island. 58. Hot Spots provide a method of tracing the of plate motion.

9 59. Over 40 Hot Spots have been identified. About a dozen of these are located along the Ridge. It has also been suggested that about 200 mya these Hot Spots contributed to the breakup of Pangea. CHAPTER 12 WHAT DRIVES PLATE MOTIONS 60. The main force driving Earth's plates is. 61. A form of gravity sliding caused by the elevated position of oceanic ridges is called. 62. is driven by cool oceanic lithospheric plates that sink into the asthenosphere. 63. consists of large cells in which warm, less dense material rises and cooler, more dense material sinks. 64. consist of narrow zones of upward flow of hot material. 65. slabs of oceanic lithosphere represent the downwardmoving portion of the convective flow in the mantle. 66. Upwelling at oceanic ridges and represent the upward-flowing arms of the convective mechanism in the mantle. CHAPTER 13 PANGAEA: BEFORE AND AFTER 67. Scientists are confident that Plate Tectonics has operated for at least billion years. 68. They predict that in 10 million years Los Angeles will lie of San Francisco. 69. The movement of Africa towards may be the next big mountain building event as the Mediterranean Sea is consumed in much the same way as the Tethys sea was consumed as India docked on Asia to form the Himalayas. 70. They also predict that Australia, New Guinea and the Philippines are on a collision course with Southeast. 71. These movements indicate that at some time in the future a new will be formed. Submit this worksheet for marks.