Chapter 15 Earths Crust

15. When melted rock rises through cracks in the sea floor, it cools and hardens to form new crust. The new crust pushes the older crust away from the mid-ocean ridge. What do you call this process? A. Sea-floor spreading B. Sea-floor erosion C. Sea-floor drift D. Sea-floor oozing

A

18. A mid-ocean ridge is most likely to form A. Where two oceanic plates move apart B. Where a continental plate slides under an oceanic plate C. Where one oceanic plate slides under another oceanic plate D. Where two continental plates collide

A

21. Which layer of the Earth is made up of mostly oxygen, silicon, and aluminum? A. Crust B. Mantle C. Inner core D. Outer core

A

28. At which of these locations is an earthquake most likely to occur? A. A transform boundary B. A convergent boundary between two oceanic plates C. A divergent boundary between two oceanic plates D. The middle of a continental plate

A

3. Which layer of Earth is composed mostly of liquid water and different types of rock crystals such as quartz? A. The crust B. The mantle C. The core D. The asthenosphere

A

32. What type of boundary forms when plates move apart; they are usually found under the ocean where mid-ocean ridges form? A. divergent boundary B. convergent boundary C. transform boundary D. earthquake boundary

A

33. There are three types of convergent boundaries. Which type forms when continental lithosphere on one plate collides with continental lithosphere on another plate; can produce very tall mountains? A. continent-continent boundaries B. continent-ocean boundaries C. ocean-ocean boundaries D. all of the above

A

36. Scientists theorize that there are the three possible reasons that tectonic plates move. According to scientists, which of the following are reasons that tectonic plates probably move? A. Convection, slab pull, ridge push B. Earthquakes, deformation, tidal waves C. Solar radiation, nuclear radiation, radiation from decay D. Earthquakes, volcanic activity, tidal waves

A

38. The layer of Earth that makes up approximately 1% of Earth's mass is the A. Crust B. Mantle C. Inner core D. Outer core

A

4. The thinnest layer of Earth ranges in thickness between 7 km and 70 km. Which layer is being described? A. The crust B. The mantle C. The outer core D. The inner core

A

42. What is it called when currents are produced when hot material in the mantle rises toward the surface and colder material sinks; and the currents pull the plates over the earth's surface? A. convection B. ridge push C. slab pull D. ridge-slab push

A

48. If the older rock is found on the outside of a fold, what type of fold is it? A. syncline B. anticline C. monocline D. octocline

A

52. In this type of fault the hanging wall moves up or the footwall moves down, or both happen; compression stress pushes the rock together. This type of fault is usually found at convergent boundaries. What type of fault is this? A. reverse fault B. normal fault C. divergent fault D. tension fault

A

54. What type of mountain is formed when tension makes the lithosphere break into many normal faults; pieces of the lithosphere drop down (Grand Tetons)? A. fault-block mountain B. folded mountain C. volcanic mountain D. snow-capped mountain

A

57. What are two types of vertical (up/down) movement of the crust? A. Uplift and subsidence B. Uplift and downpush C. Uplift and pushdown D. Uplift and sinking

A

6. What is the name of the outermost layer that is cool, solid, and includes all of the crust and a small part of the upper mantle; it is divided into pieces that move over the Earth's surface? A. lithosphere B. asthenosphere C. mesosphere D. outer core

A

1. Scientists divide the Earth into three main layers based upon composition. The Earth's three main layers are A. crust, lithosphere, mantle B. crust, mantle, core C. crust, mantle, mesosphere D. crust, lithosphere, core

B

10. Which of the following is the most likely place for an ocean trench to occur? A. A transform boundary between two oceanic plates. B. A convergent boundary between two oceanic plates. C. A divergent boundary between two continental plates. D. A transform boundary between a continental plate and an oceanic plate.

B

11. What is likely to form when two continental plates push together? A. New sea floor B. Mountains C. A volcano D. A rift valley

B

14. What do you call mountain chains on the ocean floor? A. Underwater volcanoes B. Mid-ocean ridges C. Pangaea hills D. Ocean alpines

B

2. Which layer of the Earth contains most (67%) of the Earth's mass? A. The crust B. The mantle C. The outer core D. The inner core

B

22. Which statement is true about Earth's tectonic plates? A. They float on the lithosphere and move many kilometers each year. B. They float on the asthenosphere and move a few centimeters each year. C. They do not move. D. They float on the core and move a few centimeters each year.

B

25. What are tectonic plates? A. The Earth's mantle broken into many gliding pieces. B. The Earth's lithosphere broken into many pieces moving slowly over the asthenosphere C. Depressions in the Earth's crust D. Non-moving, rocky pieces of the Earth's crust

B

29. A volcanic mountain chain is most likely to form A. Where two oceanic plates move apart B. Where an oceanic plate slides under a continental plate C. Where one oceanic plate slides under another oceanic plate D. Where two continental plates collide

B

31. What type of boundary forms when plates move together? (There are three types.) A. divergent boundary B. convergent boundary C. transform boundary D. earthquake boundary

B

35. There are three types of convergent boundaries. Which type forms when continental lithosphere on one plate collides with ocean lithosphere on another plate; can cause mountain chains to form? A. continent-continent boundaries B. continent-ocean boundaries C. ocean-ocean boundaries D. all of the above

B

41. What is it called when gravity pulls newly formed lithosphere downward and away from the mid- ocean ridge; and the rest of the plate moves because of this force? A. convection B. ridge push C. slab pull D. ridge-slab push

B

49. Where do you find the youngest rock on an anticline fold? A. The inside of the fold. B. The outside of the fold. C. The middle of the fold. D. The top of the fold.

B

5. Scientists divide the Earth into five layers based on physical properties. These five layers are called A. upper crust, lower crust, mantle, outer core, inner core B. crust, upper mantle, lower mantle, outer core, inner core C. lithosphere, asthenosphere, mesosphere, outer core, inner core D. lithosphere, asthenosphere, upper mantle, lower mantle, core

B

51. In this type of fault the hanging wall moves down or the footwall moves up, or both happen; tension stress pulls the rock apart. This type of fault is usually found at divergent boundaries. What type of fault is this? A. reverse fault B. normal fault C. divergent fault D. tension fault

B

53. What type of mountain is formed when rock layers are squeezed together and pushed upward, usually at convergent boundaries where continents collide (Smoky Mountains)? A. fault-block mountain B. folded mountain C. volcanic mountain D. snow-capped mountain

B

7. What is the name of the layer that is hot, solid rock; it is the "plastic" layer of the mantle on which tectonic plates move? A. lithosphere B. asthenosphere C. mesosphere D. outer core

B

9. In which layer of Earth is the asthenosphere located? A. Crust B. Mantle C. Inner core D. Outer core

B

13. Approximately 245 million years ago, all continents were joined into a single "super continent" landmass called A. Laurasia B. Eurasia C. Pangaea D. Gondwana

C

16. Throughout Earth's history, the north and south poles have switched places many times. What is this process called? A. pole switching B. pole diffraction C. magnetic reversal D. magnetic switching

C

27. What type of boundary forms when plates slide past each other horizontally; usually found near mid-ocean ridges. (The San Andreas fault system in California is this type of boundary.) A. divergent boundary B. convergent boundary C. transform boundary D. earthquake boundary

C

34. There are three types of convergent boundaries. Which type forms when ocean lithosphere on one plate collides with ocean lithosphere on another plate; can form volcanic islands along the plate boundaries? A. continent-continent boundaries B. continent-ocean boundaries C. ocean-ocean boundaries D. all of the above

C

37. Which is the best description of where earthquakes are likely to occur? A. In the middle of a continent B. Along a coastline C. Along two plate boundaries D. In the middle of the ocean

C

39. Which of these must happen for the sea floor to spread apart? A. A flood B. A hurricane C. Plate movement D. Volcanic eruption

C

40. What is it called when cold, sinking lithosphere at the edges of a tectonic plate pulls the rest of the plate across the earth's surface? A. convection B. ridge push C. slab pull D. ridge-slab push

C

47. What is most likely to happen when two plates carrying oceanic crust converge? A. A lake will form. B. A hot spot will form. C. One plate will be subducted. D. Folded mountains will form.

C

50. What occurs when rock actually breaks under stress? A. It folds. B. It forms a vee shape. C. It gets a fault. D. It shatters.

C

55. What type of mountain is formed when melted rock erupts onto the earth's surface; most are found at convergent boundaries (Andes)? A. fault-block mountain B. folded mountain C. volcanic mountain D. snow-capped mountain

C

59. What do you call a set of deep cracks that form at a divergent boundary? A. subsistence zone B. rip zone C. rift zone D. sink hole

C

8. What is the name of the layer that is comprised of the lower part of the mantle and extends to the Earth's core? A. lithosphere B. asthenosphere C. mesosphere D. outer core

C

20. ______________ boundaries form when continental lithosphere on one plate collides with oceanic lithosphere on another plate.

Convergent

44. In a reverse fault, the hanging wall moves up, or the footwall moves down, or both. Reverse faults are common at ____________ boundaries, where plates collide.

Convergent

12. Which of the following best describes the composition of the inner core of the Earth? A. Liquid iron and nickel B. Carbon dioxide and ice C. Quartz and oxygen D. Solid iron and nickel

D

17. Where are volcanic mountains most likely to form? A. At a convergent boundary between two oceanic plates. B. At a transform boundary between two oceanic plates C. At a convergent boundary between two continental plates. D. At a convergent boundary between a continental plate and an oceanic plat

D

23. Which of these processes is not related to tectonic plate movement? A. Volcanic activity. B. Earthquakes C. Sea-floor spreading D. erosion

D

26. What is the rate of movement of tectonic plates? A. few millimeters per year B. few feet per year C. approximately one mile per year D. approximately 2.5 centimeters per year

D

30. Earth's crust is made up of oceanic crust and continental crust. Which statement about oceanic crust is true? A. It is less dense than continental crust. B. It is older than continental crust. C. It is thicker than continental crust. D. It is denser than continental crust.

D

56. What is the area (found around the edge of the Pacific Ocean) where most of the Earth's active volcanoes are located called? A. Ring of Smoke B. Ring of Volcanoes C. Ring of Pluto D. Ring of Fire

D

58. Which of the following may cause subsidence and/or uplift? A. temperature changes B. changes in weight on the crust C. fault-block mountains D. all of the above

D

19. There are three types of plate boundaries: • _____________ boundaries, where plates move apart; • _____________ boundaries, where plates move together; and • _____________ boundaries, where plates slide past each other.

Divergent Convergent Transform

45. Fault-block mountains form when tension makes the ___________ break into many __________faults. Along these faults, pieces of the lithosphere drop down compared with other pieces.

Lithosphere, Normal

46. Most of Earth's active volcanoes are concentrated around the edge of the Pacific Ocean. This area is known as the ___________.

Ring of Fire

24. When denser oceanic lithosphere sinks underneath the continental lithosphere, the process is called ___________________.

Subduction

43. In a normal fault, the hanging wall moves down, or the footwall moves up, or both. Normal faults form when rock is under____________. Tension is stress that pulls rock apart. Therefore, normal faults are common along ____________ boundaries, where Earth's crust stretches.

Tension, Divergent