Name Class Date
Chapter 10Volcanoes and Other Igneous ActivityChapter Test
Multiple Choice
Write the letter that best answers the question or completes the statement on
the line provided.
1.Magma forms when solid rock in the crust and upper
mantle
a.partially melts.
b.crystallizes.
c.vaporizes.
d.cools.
2.Which type of landform develops at plate boundaries where
one oceanic plate descends beneath another?
a.rift valley
b.volcanic island arc
c.mountain formed by a batholith
d.lava plateau
3.At divergent plate boundaries in the ocean, magma rises
and melts because of
a.higher temperatures at the surface.
b.a decrease in pressure.
c.intrusive plutons at the boundary.
d.increased silica content of magma.
4.What are the landforms at divergent ocean plate
boundaries?
a.mid-ocean ridges
b.island arcs
c.continental arcs
d.ocean trenches
5.Most intraplate volcanic activity occurs where
a.oceanic plates diverge.
b.mantle plumes rise toward the surface within a plate.
c.hot magma descends into the mantle under a plate.
d.oceanic and continental plates converge.
6.As the temperature of lava increases,
a.its viscosity decreases.
b.it begins to harden.
c.its viscosity increases.
d.it can flow a much shorter distance.
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7.What type of volcano is fairly symmetrical and has both
layers of lava and pyroclastic deposits?
a.a cinder cone volcano
b.a shield volcano
c.a pyroclastic volcano
d.a composite cone volcano
8.What is a caldera?
a.a fiery volcanic explosion
b.a type of volcano
c.a large depression in a volcano
d.a very large volcanic bomb
9.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.
10.Structures that form from the cooling and hardening of
magma beneath Earth’s surface are
a.vents.
b.calderas.
c.lahars.
d.plutons.
11.Which of the following is NOT a factor in how violently or
quietly a volcano erupts?
a.magma’s composition
b.magma’s temperature
c.magma’s concentration of dissolved gases
d.magma’s depth inside a volcano’s vent
12.What is a volcanic bomb
a.a very violent volcanic explosion
b.a particle larger than 64 mm in size ejected as glowing lava
c.a pocket of gas that is released suddenly
d.a tiny particle of ejected rock less than 64 mm in size
13.The particles produced in volcanic eruptions are called
a.pyroclastic materials.
b.laccoliths.
c.calderas.
d.volcanic stocks.
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14.Which of the following plays a major part in determining
the form of a volcano?
a.elevation above sea level
b.magma composition
c.local soil type
d.nearness of other volcanoes
15.When a common type of basaltic lava hardens, it forms aa,
which has
a.a surface made of cinders.
b.a smooth surface that is wrinkled.
c.a rough, jagged surface.
d.holes that ooze hot water.
16.Most shield volcanoes have grown from the ocean floor
to form
a.islands.
b.dikes.
c.canyons.
d.tectonic plates.
17.The broad, slightly dome-shaped volcanoes of Hawaii are
a.composite cone volcanoes.
b.pyroclastic volcanoes.
c.shield volcanoes.
d.cinder cone volcanoes.
18.Which type of intrusive feature forms when magma is
injected into fractures cutting across rock layers?
a.a laccolith
b.a dike
c.a lava plateau
d.a sill
19.Which of the following is NOT true of a batholith?
a.It may be uplifted and then exposed by erosion.
b.It is the largest intrusive igneous body.
c.It may form the core of a mountain range.
d.It is often a small part of a sill.
20.Which of the following is similar to a batholith but has less
than 100 square kilometers exposed?
a.stock
b.sill
c.laccolith
d.dike
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Completion
Complete each statement on the line provided.
1.Descending into Earth’s interior, temperature, as well as pressure
on rock, .
2.Where slabs of oceanic lithosphere are subducted under
continental lithosphere, a volcanic arc
can form.
3.Gases escaping from volcanoes often include
, , nitrogen, and sulfur,
with lesser amounts of chlorine, hydrogen, and argon.
4.The accumulation of fluid basaltic lava produces a(n)
volcano.
5.The most explosive volcanic eruptions come from
volcanoes.
6.Saturated volcanic debris that rapidly moves down steep, volcanic
slopes as a mudflow is a(n) .
7.The magma that feeds most volcanoes moves from a magma
chamber toward the surface through .
8.Rhyolitic lavas are very viscous
because they have a high
content.
9.A(n) lava
flow resembles the twisted braids
in rope as it cools and hardens.
10.A volcanic
forms when the rock in a pipe is
resistant to erosion and remains
standing above the surface after
the rest of the volcano has worn
away.
11.Another name for a composite
cone volcano is a(n)
.
Use Figure 1 to answer the following
four questions. Write the correct letter
on the line provided.
12.Using Models Sills are located at
.
13.A batholith is the underground
feature at .
14.Feature is a laccolith.
15.A(n) forms as a flat layer when magma is
forced between sedimentary layers near the surface.
16.Part of a dike is exposed at the surface at .
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Short Answer
In complete sentences, write the answers to the questions on the lines
provided.
1.Describe three factors that affect how magma forms.
2.How is the location of most of Earth’s volcanoes related to plate
boundaries?
3.Why do volcanoes with very viscous magmas erupt the most
explosively?
Use the table to answer the following two questions.
Magma CompositionVolcano Type / Composition / Silica Con / Viscosity / Gas Content
A / Basaltic / least (~50%) / least / least (1–2%)
B / Andesitic / Intermediate
(~60%) / intermediate / Intermediate
(3–4%)
C / Rhyolitic / most (~70%) / greatest / most (4–6%)
4.Using Tables and Graphs Which type of volcano will have the
quietest type of eruption? Explain your answer.
5.Why is the type C volcano likely to explode violently?
6.Describe the shape and composition of a cinder cone.
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7.Applying Concepts Is it likely that a volcano that erupted
thousands of years ago and is still active today is a cinder cone
volcano? Explain your answer.
8.Why are pyroclastic flows not associated with shield volcanoes?
9.Classifying How do scientists classify intrusive igneous features?
10.Inferring How might the surface landscape above a laccolith
look? Explain your answer.
Essay
In complete sentences, write the answer to the question on the lines provided.
1.Earth as a System The eruption of Mount Pinatubo in 1991 sent
huge clouds of ash into the atmosphere. For a short period after
the eruption, instruments measured a slight drop in global
temperatures. Infer why this happened.
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