Focus: Lithosphere, Plate Tectonics, Earth’s Composition, and Geological Processes
Correct answer of each question given just after D option
1. Which of the following is NOT a major discontinuity within the Earth’s interior?
a) Mohorovicic discontinuity b) Gutenberg discontinuity c) Lehmann discontinuity d) Conrad discontinuity
D
2. The asthenosphere is characterized by:
a) High rigidity and low viscosity b) Low rigidity and high viscosity c) High rigidity and high viscosity d) Low rigidity and low viscosity
D
3. Felsic minerals are typically enriched in:
a) Iron and magnesium b) Calcium and sodium c) Silicon and aluminum d) Potassium and manganese
C
4. Which type of plate boundary is associated with the formation of new oceanic crust?
a) Convergent b) Divergent c) Transform d) Subduction
B
5. The concept of isostasy explains the relationship between:
a) Crustal thickness and elevation b) Plate tectonics and earthquakes c) Mantle convection and volcanism d) Ocean currents and climate
A
6. The Wadati-Benioff zone is associated with:
a) Mid-ocean ridges b) Transform faults c) Subduction zones d) Hotspots
C
7. Which of the following is NOT a driving force of plate tectonics?
a) Slab pull b) Ridge push c) Mantle convection d) Earth’s rotation
D
8. The Wilson Cycle describes:
a) The formation and breakup of supercontinents b) The evolution of oceanic crust c) The cycle of volcanic activity d) The movement of continents through time
A
9. Oceanic crust is primarily composed of:
a) Granite b) Basalt c) Rhyolite d) Andesite
B
10. The deepest part of the ocean is found in:
a) The Mariana Trench b) The Puerto Rico Trench c) The Tonga Trench d) The Java Trench
A
11. The “Ring of Fire” is a region of high volcanic and seismic activity located around the:
a) Atlantic Ocean b) Indian Ocean c) Arctic Ocean d) Pacific Ocean
D
12. The Moho discontinuity marks the boundary between:
a) Crust and mantle b) Mantle and outer core c) Outer core and inner core d) Lithosphere and asthenosphere
A
13. Mantle plumes are thought to be responsible for:
a) The formation of mid-ocean ridges b) The creation of subduction zones c) The eruption of hotspot volcanoes d) The movement of tectonic plates
C
14. The process of continental rifting can eventually lead to the formation of:
a) Mountains b) New oceans c) Earthquakes d) Volcanoes
B
15. The oldest rocks on Earth are found in:
a) The ocean floor b) Continental shields c) Mid-ocean ridges d) Volcanic island arcs
B
16. The “supercontinent cycle” refers to the periodic assembly and breakup of large continental landmasses. Which supercontinent existed approximately 200 million years ago?
a) Rodinia b) Columbia c) Pannotia d) Pangaea
D
17. The Mohorovicic discontinuity (Moho) is a seismic boundary that separates:
a) The lithosphere from the asthenosphere b) The crust from the mantle c) The mantle from the outer core d) The outer core from the inner core
B
18. In plate tectonics, the process of “slab rollback” refers to:
a) The subduction of oceanic lithosphere beneath continental lithosphere b) The retreat of a subducting slab due to its own weight and density c) The collision of two continental plates d) The formation of new oceanic crust at mid-ocean ridges
B
19. Which type of seismic wave cannot travel through liquids?
a) P-waves b) S-waves c) Love waves d) Rayleigh waves
B
20. Ophiolites are geological complexes that represent:
a) Ancient continental crust b) Remnants of subducted oceanic lithosphere c) Volcanic island arcs d) Mantle plumes
B
21. Which of the following is NOT a major component of the Earth’s magnetic field?
a) Inner core b) Outer core c) Mantle d) Crust
C
22.The “Benioff zone” is a planar zone of seismicity associated with:
a) Transform plate boundaries b) Divergent plate boundaries c) Convergent plate boundaries d) Intraplate hotspots
C
23. The concept of “mantle convection” refers to:
a) The circulation of molten magma in the Earth’s mantle b) The movement of tectonic plates due to gravitational forces c) The slow, creeping motion of solid mantle rock due to heat transfer d) The generation of heat in the Earth’s interior through radioactive decay
C
24. Which type of rock is most likely to be found in a continental shield?
a) Basalt b) Granite c) Andesite d) Peridotite
B
25. The “Pacific Ring of Fire” is characterized by:
a) Frequent earthquakes and volcanic eruptions b) High rates of seafloor spreading c) Extensive mountain ranges d) Large sedimentary basins
A
26. The term “lithospheric plate” refers to:
a) A rigid segment of the Earth’s crust b) A rigid segment of the Earth’s mantle c) A rigid segment of the Earth’s crust and uppermost mantle d) A molten region within the Earth’s mantle
C
27. The “magnetic striping” observed on the ocean floor is evidence for:
a) Seafloor spreading and reversals of the Earth’s magnetic field b) The movement of continents through time c) The formation of volcanic island arcs d) The occurrence of earthquakes
A
28. The “shadow zone” for seismic waves is a region where:
a) Seismic waves are amplified b) Seismic waves are not detected c) Seismic waves change direction d) Seismic waves are refracted
B
29. The “elastic rebound theory” explains:
a) The formation of mountains b) The generation of earthquakes c) The movement of tectonic plates d) The circulation of magma in the mantle
B
30. The “mantle wedge” is a region of the mantle located:
a) Above a subducting slab b) Below a subducting slab c) At mid-ocean ridges d) At hotspots
A
31. What is the approximate average thickness of continental crust?
a) 5 km b) 15 km c) 40 km d) 70 km
C
32. Which type of plate boundary is associated with the formation of island arcs and volcanic mountains?
a) Oceanic-oceanic convergent boundary b) Oceanic-continental convergent boundary c) Continental-continental convergent boundary d) Transform boundary
A
33. Which mineral is NOT a major constituent of the Earth’s mantle?
a) Olivine b) Pyroxene c) Garnet d) Quartz
D
34. The Wadati-Benioff zone is a zone of seismicity that:
a) Marks the boundary between the crust and the mantle b) Occurs within the asthenosphere c) Defines the path of a subducting plate d) Is associated with mid-ocean ridges
C
35. Which type of rock is formed by the cooling and solidification of magma or lava?
a) Sedimentary b) Metamorphic c) Igneous d) None of the above
C
36. The term “orogeny” refers to:
a) The formation of volcanoes b) The breakup of supercontinents c) The process of mountain building d) The erosion of mountain ranges
C
37. Which of the following is NOT a major tectonic plate?
a) Eurasian Plate b) Pacific Plate c) Nazca Plate d) Siberian Plate
D
39. The “shadow zone” for P-waves is a region where:
a) P-waves are amplified b) P-waves are not detected c) P-waves change direction d) P-waves are refracted
B
40. The “Curie point” is the temperature at which:
a) Rocks become molten b) Minerals lose their magnetic properties c) Earthquakes are most likely to occur d) Volcanic eruptions are most violent
B
41. The “mantle transition zone” is a region within the mantle where:
a) Seismic wave velocities abruptly increase b) Seismic wave velocities abruptly decrease c) The mantle transitions from solid to liquid d) The mantle transitions from liquid to solid
A
42. Which type of plate boundary is associated with the formation of the Himalayas?
a) Oceanic-oceanic convergent boundary b) Oceanic-continental convergent boundary c) Continental-continental convergent boundary d) Transform boundary
C
43. The “Mid-Atlantic Ridge” is an example of a:
a) Convergent plate boundary b) Divergent plate boundary c) Transform plate boundary d) Subduction zone
B
44. The “San Andreas Fault” in California is an example of a:
a) Convergent plate boundary b) Divergent plate boundary c) Transform plate boundary d) Subduction zone
C
45. Which type of seismic wave causes the most damage during an earthquake?
a) P-waves b) S-waves c) Love waves d) Rayleigh waves
C
46. The “mantle plume” hypothesis explains the origin of:
a) Mid-ocean ridges b) Subduction zones c) Island arcs d) Hotspot volcanoes
D
47. The Earth’s mantle is primarily composed of:
a) Peridotite b) Basalt c) Granite d) Andesite
A
48. The concept of “apparent polar wander” is used to explain:
a) The migration of the Earth’s magnetic poles over geological time b) The rotation of the Earth on its axis c) The precession of the Earth’s rotational axis d) The change in the Earth’s tilt
A
49. Which of the following is NOT a type of mantle xenolith?
a) Peridotite b) Eclogite c) Kimberlite d) Obsidian
D
50. The “low velocity zone” (LVZ) in the mantle is characterized by:
a) Reduced seismic wave velocities b) Increased seismic wave velocities c) An absence of seismic waves d) Rapidly flowing molten rock
A
51. The “triple junction” is a point where:
a) Two tectonic plates meet b) Three tectonic plates meet c) A tectonic plate changes direction d) A tectonic plate is subducted
B
52. The “magnetic inclination” of a rock sample indicates:
a) The direction to the magnetic north pole at the time the rock formed b) The distance from the magnetic equator at the time the rock formed c) The latitude at which the rock formed d) The age of the rock
C
53. The “supercontinent cycle” is driven by:
a) Plate tectonics and mantle convection b) Changes in the Earth’s rotation rate c) Fluctuations in solar radiation d) Variations in the Earth’s magnetic field
A
54. The “Moho” discontinuity is deeper beneath:
a) Continents b) Oceans c) Mid-ocean ridges d) Subduction zones
55. The process of “delamination” refers to:
a) The detachment and sinking of dense lower crustal material into the mantle b) The collision of two continental plates c) The formation of new oceanic crust at mid-ocean ridges d) The eruption of hotspot volcanoes
A
56. The “geoid” is a model of the Earth’s shape that represents:
a) The average sea level b) The shape of the Earth’s core c) The distribution of continents and oceans d) The variations in the Earth’s gravity field
A
57. The “paleomagnetism” of a rock sample can reveal:
a) The age of the rock b) The composition of the rock c) The past location and orientation of the rock d) The intensity of the Earth’s magnetic field at the time of rock formation
C
58. The “olivine-spinel transition zone” in the mantle is marked by:
a) A decrease in seismic wave velocities b) An increase in seismic wave velocities c) A change in the mineralogy of the mantle d) A change in the density of the mantle
B
59. The “Wilson cycle” describes:
a) The opening and closing of ocean basins b) The formation and breakup of supercontinents c) The cycle of volcanic activity d) The movement of continents through time
A
60. The “mantle wedge” is a region of the mantle located:
a) Above a subducting slab b) Below a subducting slab c) At mid-ocean ridges d) At hotspots
A
61. The “elastic rebound theory” explains:
a) The formation of mountains b) The generation of earthquakes c) The movement of tectonic plates d) The circulation of magma in the mantle
B
