Question 1

Viscosity does NOT depend on

Accepted Answer

A)   temperature.
B)   volatile content.
C)   silica content.
D)   the total volume of the magma body.E) C) and D)
F) A) and D)

Question 2

Bombs,ash,and cinders are all examples of

Accepted Answer

A)   intrusive igneous rocks.
B)   lava flows.
C)   volatiles.
D)   pyroclastic debris.E) A) and B)
F) None of the above

Question 3

In general,when rock is partially melted,the chemistry of the melt is

Accepted Answer

A)   more mafic than the original chemistry of the rock that was partially melted.
B)   more felsic than the original chemistry of the rock that was partially melted.
C)   identical to the original chemistry of the rock that was partially melted.
D)   completely unpredictable (it could be more mafic or more felsic) .E) None of the above
F) All of the above

Question 4

A fragmental,extrusive igneous rock is referred to as which of the following?

Accepted Answer

A)   crystalline
B)   vitric
C)   pyroclastic
D)   vesicularE) All of the above
F) A) and C)

Question 5

An igneous rock with a mixed texture consisting of coarse crystals (phenocrysts) surrounded by fine crystals (groundmass) is termed

Accepted Answer

A)   porphyritic.
B)   phaneritic.
C)   aphanitic.
D)   vitric.E) B) and D)
F) A) and B)

Question 6

What is obsidian? How does it form?

Accepted Answer

Obsidian is a vesicle-free,fel...

Question 7

A body of rock starts at location A in the graph below.The rock,over a period of time,moves to location B and begins to melt.This is an example of melting due to

Accepted Answer

A)   fractional crystallization.
B)   heat transfer.
C)   addition of volatiles.
D)   decompression.E) B) and C)
F) None of the above

Question 8

Important volatiles in magmas include

Accepted Answer

A)   mafic minerals,such as olivine.
B)   potassium and aluminum.
C)   water and carbon dioxide.
D)   silicon and iron.E) None of the above
F) A) and D) C

Question 9

Which of the following processes is not responsible for the formation of magma within the Earth?

Accepted Answer

A)   decompression (due to a drop in pressure) 
B)   addition of volatiles
C)   transfer of heat from adjacent magma or very hot rocks
D)   loss of volatiles to the atmosphereE) B) and D)
F) A) and C)

Question 10

List the four major magma compositions in order of silica content.
 $\begin{array}{c}
\begin{array}{|l|}
 \hline \text { Silica Content}\
 \hline \
\text { Highest}\
\
\
\text { Lowest}\
 \hline 
\end{array}
\begin{array}{l|}
 \hline \text { Magma Compositions }\
 \hline \
 \hline \
 \hline \
 \hline \
 \hline \
 \hline 
\end{array}
\end{array}$

Accepted Answer

The answer of List the four major magma compositions in...

Question 11

Briefly explain why and how magmas rise within the Earth.

Accepted Answer

Magmas are less dense than their solid s...

Question 12

If you find a tuff in the field,what type of geologic activity could you reasonably assume has occurred?

Accepted Answer

A)   an igneous intrusion
B)   sea-level rise
C)   a volcanic eruption
D)   tectonic upliftE) All of the above
F) C) and D)

Question 13

When magma solidifies below the surface of the Earth,________ are formed.

Accepted Answer

A)   intrusive igneous rocks
B)   extrusive igneous rocks
C)   volatiles
D)   pyroclastic rocksE) None of the above
F) A) and D)

Question 14

Which type of magma has the greatest silica content?

Accepted Answer

A)   felsic
B)   intermediate
C)   mafic
D)   ultramaficE) None of the above
F) A) and D)

Question 15

Volatiles refer to substances that

Accepted Answer

A)   crystallize most rapidly out of a melt.
B)   melt immediately upon contact with a hot body of magma.
C)   are highly flammable.
D)   evaporate easily and exist as gases.E) B) and D)
F) A) and B) D

Question 16

The figure below shows mafic magma as it meets the seafloor,which cools to form an igneous rock called

Accepted Answer

A)   pegmatite.
B)   pillow basalt.
C)   laccolith.
D)   pluton.E) C) and D)
F) B) and D) B

Question 17

The difference between magma and lava is

Accepted Answer

A)   magma cools more rapidly than lava.
B)   magma is found at the surface,whereas lava is found below the surface.
C)   magma is melt underground,whereas lava is melt that has emerged from the surface.
D)   There is no difference; the two terms mean the same thing.E) A) and D)
F) A) and B)

Question 18

Rhyolite and granite are both felsic igneous rocks,although they have different cooling histories,and consequently different textures.Explain the difference between the two rock types from a cooling perspective and be specific about which igneous texture can be applied to which rock.

Accepted Answer

Rhyolite is extrusive and consequently c...

Question 19

What is fractional crystallization? Briefly explain how it works and why different types of magmas result.

Accepted Answer

Fractional crystallization is a process ...

Question 20

A vast,composite intrusive igneous body that covers hundreds of square kilometers (in a map view) is called a

Accepted Answer

A)   pluton.
B)   dike.
C)   batholith.
D)   sill.E) B) and C)
F) None of the above

Exam 6: Up From the Inferno: Magma and Igneous Rocks

Viscosity does NOT depend on

Correct Answer
verified

Bombs,ash,and cinders are all examples of

Correct Answer
verified

In general,when rock is partially melted,the chemistry of the melt is

Correct Answer
verified

A fragmental,extrusive igneous rock is referred to as which of the following?

Correct Answer
verified

An igneous rock with a mixed texture consisting of coarse crystals (phenocrysts) surrounded by fine crystals (groundmass) is termed

Correct Answer
verified

What is obsidian? How does it form?

Correct Answer
verified
Obsidian is a vesicle-free,fel...
View Answer

Correct Answer
verified

Important volatiles in magmas include

Correct Answer
verified
C

Which of the following processes is not responsible for the formation of magma within the Earth?

Correct Answer
verified

Correct Answer
verified

Briefly explain why and how magmas rise within the Earth.

Correct Answer
verified
Magmas are less dense than their solid s...
View Answer

If you find a tuff in the field,what type of geologic activity could you reasonably assume has occurred?

Correct Answer
verified

When magma solidifies below the surface of the Earth,________ are formed.

Correct Answer
verified

Which type of magma has the greatest silica content?

Correct Answer
verified

Volatiles refer to substances that

Correct Answer
verified
D

The figure below shows mafic magma as it meets the seafloor,which cools to form an igneous rock called

Correct Answer
verified
B

The difference between magma and lava is

Correct Answer
verified

Rhyolite and granite are both felsic igneous rocks,although they have different cooling histories,and consequently different textures.Explain the difference between the two rock types from a cooling perspective and be specific about which igneous texture can be applied to which rock.

Correct Answer
verified
Rhyolite is extrusive and consequently c...
View Answer

What is fractional crystallization? Briefly explain how it works and why different types of magmas result.

Correct Answer
verified
Fractional crystallization is a process ...
View Answer

A vast,composite intrusive igneous body that covers hundreds of square kilometers (in a map view) is called a

Correct Answer
verified

Exam 6: Up From the Inferno: Magma and Igneous Rocks

Viscosity does NOT depend on

Correct AnswerverifiedShow Answer

Bombs,ash,and cinders are all examples of

Correct AnswerverifiedShow Answer

In general,when rock is partially melted,the chemistry of the melt is

Correct AnswerverifiedShow Answer

A fragmental,extrusive igneous rock is referred to as which of the following?

Correct AnswerverifiedShow Answer

An igneous rock with a mixed texture consisting of coarse crystals (phenocrysts) surrounded by fine crystals (groundmass) is termed

Correct AnswerverifiedShow Answer

What is obsidian? How does it form?

Correct AnswerverifiedObsidian is a vesicle-free,fel...View AnswerShow Answer

A body of rock starts at location A in the graph below.The rock,over a period of time,moves to location B and begins to melt.This is an example of melting due to

Correct AnswerverifiedShow Answer

Important volatiles in magmas include

Correct AnswerverifiedC

Which of the following processes is not responsible for the formation of magma within the Earth?

Correct AnswerverifiedShow Answer

Correct AnswerverifiedShow Answer

Briefly explain why and how magmas rise within the Earth.

Correct AnswerverifiedMagmas are less dense than their solid s...View AnswerShow Answer

If you find a tuff in the field,what type of geologic activity could you reasonably assume has occurred?

Correct AnswerverifiedShow Answer

When magma solidifies below the surface of the Earth,________ are formed.

Correct AnswerverifiedShow Answer

Which type of magma has the greatest silica content?

Correct AnswerverifiedShow Answer

Volatiles refer to substances that

Correct AnswerverifiedD

The figure below shows mafic magma as it meets the seafloor,which cools to form an igneous rock called

Correct AnswerverifiedB

The difference between magma and lava is

Correct AnswerverifiedShow Answer

Rhyolite and granite are both felsic igneous rocks,although they have different cooling histories,and consequently different textures.Explain the difference between the two rock types from a cooling perspective and be specific about which igneous texture can be applied to which rock.

Correct AnswerverifiedRhyolite is extrusive and consequently c...View AnswerShow Answer

What is fractional crystallization? Briefly explain how it works and why different types of magmas result.

Correct AnswerverifiedFractional crystallization is a process ...View AnswerShow Answer

A vast,composite intrusive igneous body that covers hundreds of square kilometers (in a map view) is called a

Correct AnswerverifiedShow Answer

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified
Obsidian is a vesicle-free,fel...
View Answer

Correct Answer
verified

Correct Answer
verified
C

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified
Magmas are less dense than their solid s...
View Answer

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified
D

Correct Answer
verified
B

Correct Answer
verified

Correct Answer
verified
Rhyolite is extrusive and consequently c...
View Answer

Correct Answer
verified
Fractional crystallization is a process ...
View Answer

Correct Answer
verified