Multiple Choice
Identify the
letter of the choice that best completes the statement or answers the question.
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1.
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Which
of the following is NOT considered to be a pyroclastic material? a. | ash | c. | cinders | b. | lapilli | d. | pahoehoe | | | | |
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2.
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Which
of the following is responsible for the partial melting of rock beneath ocean
ridges? a. | chemical
reactions with atmospheric oxygen | b. | increases in pressure | c. | decreases in
pressure | d. | increases in temperature | | |
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3.
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Most
of the active volcanoes on Earth are located in a belt known as the ____. a. | circum-Atlantic
belt | c. | Ring of
Lava | b. | Ring of
Fire | d. | East African
Rift Valley | | | | |
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4.
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A volcanic bomb is a ____. a. | very violent
volcanic explosion | b. | piece of semi-molten rock ejected as glowing
lava | c. | pocket of gas
that is released suddenly | d. | tiny particle of ejected rock less than 64 mm in
size | | |
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5.
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A volcano that is fairly symmetrical and has both layers of
lava and pyroclastic deposits is a ____. a. | cinder cone volcano | c. | pyroclastic volcano | b. | shield
volcano | d. | composite cone
volcano | | | | |
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6.
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At divergent plate boundaries in the ocean, magma rises and
melts because of ____. a. | higher temperatures at the
surface | c. | intrusive plutons at the boundary | b. | a decrease in pressure | d. | increased silica content of magma | | | | |
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7.
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Which
of the following is true about volcanic blocks and bombs? a. | Blocks are
semi-molten when ejected. | b. | Bombs are larger than blocks. | c. | Bombs are found
closer to the volcano than blocks. | d. | Bombs often have a streamlined shape. | | |
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8.
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The
most violent volcanic eruptions are associated with what type of volcano? a. | cinder
cones | c. | composite
cones | b. | shield volcanoes | d. | fissure eruptions | | | | |
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9.
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Which
of the following factors helps determine whether a volcanic eruption will be violent or relatively
quiet? a. | amount of
dissolved gases in the magma | b. | temperature of the magma | c. | composition of
the magma | d. | all of the above | | |
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10.
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What
volcanic feature is illustrated at A in Figure 10-2? a. | continental
volcanic arc | c. | hot
spot | b. | volcanic island
arc | d. | ocean
ridge | | | | |
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11.
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In
general, what is true about the composition of the igneous rocks produced in association with
subduction zone volcanic activity? a. | The rocks are rich in silica. | b. | The rocks are
low in silica. | c. | The rocks have the highest possible silica
content. | d. | The rocks contain no silica. | | |
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12.
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In
general, an increase in the confining pressure results in what change in a rock’s melting
temperature? a. | Melting
temperature stays the same. | b. | Melting temperature decreases. | c. | Melting
temperature increases. | d. | Melting temperature is not related to confining
pressure. | | |
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13.
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Which
of the following is NOT a factor affecting how violently or quietly a volcano
erupts? a. | magma’s
composition | b. | magma’s
temperature | c. | concentration of
dissolved gases in the magma | d. | size of the
volcano’s cone | | |
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14.
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The
igneous activity in Yellowstone National Park is associated with what tectonic
setting? a. | divergent plate
boundary | b. | convergent oceanic-oceanic plate
boundary | c. | intraplate setting | d. | convergent
oceanic-continental plate boundary | | |
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15.
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As the temperature of lava increases, ____. a. | its viscosity decreases | c. | its viscosity increases | b. | it begins to harden | d. | it can flow a much shorter distance | | | | |
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16.
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Lava plateaus form when ____. a. | the top of a
volcano collapses | b. | fluid basaltic lava flows out of
fissures | c. | lahars create
new landforms | d. | pyroclastic
flows erupt from volcanoes | | |
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17.
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Which of the following plays a major part in determining the
form of a volcano? a. | elevation above
sea level | c. | magma
composition | b. | local soil type | d. | nearness of
other volcanoes | | | | |
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18.
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What
type of volcano is built almost entirely from ejected lava fragments? a. | cinder
cone | c. | shield
volcano | b. | composite cone | d. | pahoehoe volcano | | | | |
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19.
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Crater Lake in Oregon was produced when ____. a. | a lava dam
blocked a river | b. | a large explosion blew out the side of a large
volcano | c. | the summit of a volcano collapsed | d. | a lava flow
erupted from a volcano | | |
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20.
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What
feature is labeled A in Figure 10-1? a. | pipe | c. | crater | b. | volcanic
neck | d. | vent | | | | |
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21.
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Most shield volcanoes have grown from the ocean floor to form
____. a. | islands | c. | tectonic
plates | b. | dikes | d. | canyons | | | | |
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