Multiple Choice
1. Which one of the following is NOT part of the continental margin?
a. continental shelf b.
continental slope
c. continental rise d.
continental trench
2. It is
thought that submarine canyons on the continental slope have been generated by
__________.
a. streams when sea level was much lower than
it is today
b. streams when sea level was much higher
than it is today
c. a submarine glaciation
d. turbidity currents
3. Which one of the following would you NOT associate with turbidity
currents?
a.
deposits of graded beds b.
density current
c.
excavation of submarine canyons d.
formation of seamounts
4. Which one of the following would most likely be
covered with thick turbidite layers?
a.
axial rift zone of an active mid-ocean spreading center
b.
upper part of a steep, narrow, submarine canyon
c.
deep-sea fan at the base of a continental slope
d.
ocean floor around a conical-shaped seamount
5. Which of the following is NOT true of deep ocean
trenches?
a. They are long and
narrow depressions.
b. They are sites
where plates plunge back into the mantle.
c. They are
geologically very stable.
d.
They may act as sediment traps.
6. The
BEST definition of the outer edge of the continental shelf is that point where
__________.
a. the gradient becomes very
gentle b. the water
depth reaches 100 fathoms
c. it meets an oceanic ridge d. a rapid
steepening of the gradient occurs
7. Seamounts ____________.
a. are a special type of oceanic
trench
b. are volcanoes that form on the
ocean floor
c. form only in the
d.
are submarine canyons found near
8. Submarine canyons found on the continental
slope are believed to have been created ____________.
a. by rivers during the ice age b. by faulting
c. because of a plate plunging into
the mantle d. none of these
9. Which
of the following is associated with ocean ridges?
a. rift zones b.
mountainous topography
c. volcanic structures d. all of these
10. How do
calcareous oozes form?
a. The particles are precipitated in warm surface waters
and sink to the bottom.
b. The particles are precipitated by bottom-dwelling
organisms.
c. The particles are
precipitated in the water column below the depth of sunlight penetration and
then sink to the bottom.
d.
The particles settle out from calcite-rich turbidity currents at depths greater
than 15,000 feet.
11. Sediments
derived primarily from the products of weathering on the continents are called
__________.
a. terrigenous sediment b.
biogenous sediment
c. hydrogenous sediment d. both terrigenous and biogenous
sediment
12. Manganese nodules are an example of
__________.
a. terrigenous sediment b. biogenous
sediment
c. hydrogenous sediment d. both terrigenous and biogenous
sediment
13. Minerals
that crystallize directly from seawater are examples of __________.
a. terrigenous sediment b. biogenous
sediment
c. hydrogenous sediment d. both
terrigenous and biogenous sediment
14. The gently
sloping submerged surface extending from the shoreline toward the deep ocean is
termed the ____________.
a. continental shelf b.
continental slope
c.
continental rise d.
submarine canyon
15. The crests of mid-oceanic ridges __________.
a. are heavily mantled with
sediment b. lie at
depths exceeding 6 kilometers
c. contain active rift zones d. are
geologically old features
16. ____________
develop where oceanic lithosphere bends downward and sinks into the mantle.
a.
Submarine canyons b.
Abyssal seamounts
c. Deep ocean trenches d. Rift
valleys on mid-ocean ridges
17. An echo
sounder operates by measuring the time required for a ____________.
a. light beam to travel from a satellite at a known
altitude to the sea bottom and back
b. radar beam to travel from a harbor patrol boat to a
fuzz-buster on a speeding yacht
c. radar beam to travel from a ship to the seafloor and
back
d. sound pulse travels from
a ship to the seafloor and back
18. The oceans cover
approximately __________ percent of Earth's surface.
a. 40 b. 50 c. 60 d. 70
19. The _______ Ocean is largest.
a.
Atlantic b. Pacific c. Indian d.
20. Which ocean has the greatest average depth?
a. Atlantic b. Pacific c. Indian d.
21. Concerning the distribution of land and water, which of the
following statements is true?
a. The percentage of land
and water is about the same in both the Northern and Southern Hemispheres.
b. The Southern Hemisphere
has much more water surface than the Northern Hemisphere.
c. The Northern Hemisphere
has much more water surface than the Southern Hemisphere.
d. None of the above is
true.
22. The
continental rise is located ____________.
a. at the top of a mid-ocean ridge
b. at the top of the continental slope
c. between an abyssal plain and continental slope
d. at the seaward edge of a
deep ocean trench
23. Which one
of the following concerning mid-ocean ridges is false?
a. They are sites for submarine eruptions of basaltic
lava.
b. They are where young lithosphere is added to the edges
of spreading, oceanic plates.
c. Terrigenous sediment coverings are very thin or
absent.
d. Sediments include thick
siliceous ooze deposits and sandy turbidite beds.
24. The __________ Ocean has more extensive abyssal plains
than the
a. Indian b. Atlantic c.
Arctic d. none of
these
25. "Black
smokers" are associated with ____________.
a. oceanic ridges
b.
mineral-rich waters
c.
hot water
d.
all of these
Matching:
Questions 28–33:
Match the ocean floor sediment with each phrase. All are level 1
questions.
a. biogenous b. terrigenous c.
hydrogenous
26. ____
manganese nodule
27. ____
calcareous ooze
28. ____
quartz sand
29. ____
diatom ooze
30. ____
turbidite deposits
31. ____ abyssal plain clay
Word Analysis:
Examine the words and/or phrases for
each question below and determine the relationship among the majority of
words/phrases. Choose the option which does not fit the pattern.
32. a. sodium chloride b. magnesium chloride c. sodium sulfate d. carbon dioxide
33. a. echo sounder b. doppler radar c.
sidescan sonar d. radar
altimeters
34. a. continental shelf b. continental rise c.
continental slope d. continental
volcanic arc
35. a. rift valley b. subduction c.
volcanic island arc d. trench
36. a. manganese nodules b. calcareous ooze c. metal sulfides d. evaporites
True –
False
______37. The west
coast of South America and the east coast of
______38. Abyssal plains with sediments covering the
seafloor igneous rocks are more extensive in the central Pacific basin than in
the
______39. Submerged, flat-topped seamounts are known as
guyots.
______40. The Atlantic and Pacific basins have oceanic
ridges; the
______41. Manganese nodules do not accumulate below 4500
meters depth because the manganese minerals are
highly soluble in seawater below that depth.
______42. Turbidites
and siliceous oozes are both biogenous sediments.
______43. Submarine
canyons form the deepest parts of the ocean basins.
______44. Compared to the Southern Hemisphere, a higher
percentage of the Northern Hemisphere is water covered.
______45. The continental rise lies at the bottom of the
continental slope.
______46. Seafloor
______47. Sand, silt, and clays deposited on the ocean
floor are described as terrigenous sediments.
Short Answer
48. The most extensive mountain range on Earth extends for about 65,000
kilometers on the ocean floor and is known as the ____________.
49. Flat-topped volcanic structures located on the floor of the deep
ocean basin are termed ____________.
50. A prominent feature of the Mid-Atlantic Ridge is a very deep linear
valley known as a ____________ valley.
51. The gently sloping submerged
surface extending from the shoreline toward the deep ocean is termed the
____________.
52. ____________ sediment consists of shells and hard parts of marine organisms.
53. Valleys
that lead from the continental shelf into deeper waters are known as ____________.
54. ____________ continental
margins typically exhibit wide, extensive, continental shelves.
55. Manganese nodules are an example of ____________ sediment.
56. A(n)
____________ is a volcanic mountain, built up from the seafloor that never reached
the sea surface.
57. ____________
continental margins occur where oceanic lithosphere is being subducted beneath
the edge of a continent.
58. A(n)
____________ is the vast, relatively deep, flat, sediment-covered portion of
the deep-ocean basin.
59. A(n)
____________ marks the site where old, oceanic lithosphere begins its descent
into a subduction zone.
Critical Thinking and Discussion Questions.
Use complete sentences,
correct spelling, and the information presented in Chapter 13 to answer the
questions below.
60. Discuss the distribution of seafloor sediments
in the ocean basins. What are the different types of sediments, and what are
the factors that control their distribution (geologic setting, climate, etc.)?
level:
2
61. How might you distinguish an ancient passive
continental margin from an active continental margin? What geologic features or
rock sequences would be unique to each one? Also, what features of modern
continental margins may not be preserved in the geologic record?
level:
3
Visualization Questions
62. Label the different features of the passive
continental margin on the diagram below.
level:
1 answer: See Figure 13.9 in Earth Science, 11e.
63. What type of continental margin is illustrated
in the diagram below?
level: 1 answer: active continental margin
64. Examine Figure 13.C below. Briefly explain the
main points of Charles Darwin’s hypothesis on coral atoll formation. Have we
tested his hypothesis and is it still thought to be correct today? Can you
think of another possible explanation that would explain the origin of such
coral atolls?
level:
2
