Question 1

What role does stoping play in the emplacement of batholiths?

Accepted Answer

Fracturing and assim...

Question 2

Igneous rocks with a two-stage intrusive-extrusive origin are recognized by a texture which is ____.

Accepted Answer

A)   aphanitic
B)   porphyritic
C)   glassy
D)   phaneritic
E)   pyroclasticF) C) and D)
G) B) and E)

Question 3

Most plutons form ____.

Accepted Answer

A)   well within plates
B)   at plate boundaries
C)   without regard to plate boundaries
D)   above the land surface
E)   all of theseF) C) and E)
G) All of the above

Question 4

Natural glass such as obsidian forms when magma does what?

Accepted Answer

A)   cools too rapidly for crystals to form
B)   cools rapidly and very tiny crystals form
C)   cools too slowly for crystals to form
D)   doesn't cool
E)   none of theseF) All of the above
G) A) and D)

Question 5

Laccoliths are sills that inflate,causing the overlying rock to bow upward.

Accepted Answer

A) True 
 B)False

Question 6

The ultramafic rock composed predominantly of ____________________ is known as peridotite and is likely the rock that makes up the part of Earth known as the ____________________.

Accepted Answer

olivine,up...

Question 7

Where are mantle plumes primarily found?

Accepted Answer

A)   divergent plate boundaries
B)   convergent plate boundaries
C)   transform plate boundaries
D)   not at plate boundaries
E)   none of theseF) B) and C)
G) D) and E)

Question 8

Briefly explain batholith formation.

Accepted Answer

Most batholiths appear to have...

Question 9

Briefly explain how pegmatites form.

Accepted Answer

Pegmatites are extremely coarse-grained granitic rocks which form as dikes,sills,and stocks from the cooling of the liquid-vapor-rich phases of felsic magmas.

Question 10

____________________ are concordant,mushroom-shaped plutons.

Accepted Answer

Laccoliths

Question 11

Granite and rhyolite are extrusive and intrusive igneous rocks of the same composition.

Accepted Answer

A) True 
 B)False

Question 12

Rapid cooling of magma results in a(n)____________________ grained texture called ____________________.

Accepted Answer

The answer of Rapid cooling of magma results in a(n)____________________...

Question 13

What two types of volcanic features result from volcanism above a mantle plume? How are hot spots related to plate boundaries?

Accepted Answer

Mantle plumes are responsible for linear...

Question 14

The process of assimilation includes the incorporation of felsic country rock.

Accepted Answer

A) True 
 B)False

Question 15

Explain how a laccolith is similar to a sill.

Accepted Answer

Both are near-surfac...

Question 16

A dark colored igneous rock with no visible crystals cooled ____.

Accepted Answer

A)   slowly in a magma chamber
B)   quickly in a magma chamber
C)   slowly on the Earth's surface
D)   quickly on the Earth's surface
E)   none of theseF) B) and C)
G) A) and E) D

Question 17

Most igneous rocks are classified by what?

Accepted Answer

A)   texture
B)   composition
C)   size
D)   texture and composition
E)   size and compositionF) A) and C)
G) A) and E)

Question 18

The most widely accepted explanation for chains of volcanoes in the oceans and lines of volcanoes on land is that they formed at ____.

Accepted Answer

A)   divergent plate boundaries
B)   normal faults
C)   hot spots
D)   convergent plate boundaries
E)   transform faultsF) A) and B)
G) A) and C)

Question 19

What does a glassy texture tell us about the history of an igneous rock?

Accepted Answer

The magma ...

Question 20

Is the process of partial melting more likely to produce magmas which are more mafic or more felsic? Why?

Accepted Answer

Felsic rocks melt at...

Exam 4: Igneous Rocks and Plutons

What role does stoping play in the emplacement of batholiths?

Correct AnswerverifiedFracturing and assim...View AnswerShow Answer

Igneous rocks with a two-stage intrusive-extrusive origin are recognized by a texture which is ____.

Correct AnswerverifiedShow Answer

Most plutons form ____.

Correct AnswerverifiedShow Answer

Natural glass such as obsidian forms when magma does what?

Correct AnswerverifiedShow Answer

Laccoliths are sills that inflate,causing the overlying rock to bow upward.

Correct AnswerverifiedShow Answer

The ultramafic rock composed predominantly of ____________________ is known as peridotite and is likely the rock that makes up the part of Earth known as the ____________________.

Correct Answerverifiedolivine,up...View AnswerShow Answer

Where are mantle plumes primarily found?

Correct AnswerverifiedShow Answer

Briefly explain batholith formation.

Correct AnswerverifiedMost batholiths appear to have...View AnswerShow Answer

Briefly explain how pegmatites form.

Correct AnswerverifiedPegmatites are extremely coarse-grained granitic rocks which form as dikes,sills,and stocks from the cooling of the liquid-vapor-rich phases of felsic magmas.

____________________ are concordant,mushroom-shaped plutons.

Correct AnswerverifiedLaccoliths

Granite and rhyolite are extrusive and intrusive igneous rocks of the same composition.

Correct AnswerverifiedShow Answer

Rapid cooling of magma results in a(n)____________________ grained texture called ____________________.

Correct AnswerverifiedShow Answer

What two types of volcanic features result from volcanism above a mantle plume? How are hot spots related to plate boundaries?

Correct AnswerverifiedMantle plumes are responsible for linear...View AnswerShow Answer

The process of assimilation includes the incorporation of felsic country rock.

Correct AnswerverifiedShow Answer

Explain how a laccolith is similar to a sill.

Correct AnswerverifiedBoth are near-surfac...View AnswerShow Answer

A dark colored igneous rock with no visible crystals cooled ____.

Correct AnswerverifiedD

Most igneous rocks are classified by what?

Correct AnswerverifiedShow Answer

The most widely accepted explanation for chains of volcanoes in the oceans and lines of volcanoes on land is that they formed at ____.

Correct AnswerverifiedShow Answer

What does a glassy texture tell us about the history of an igneous rock?

Correct AnswerverifiedThe magma ...View AnswerShow Answer

Is the process of partial melting more likely to produce magmas which are more mafic or more felsic? Why?

Correct AnswerverifiedFelsic rocks melt at...View AnswerShow Answer

Correct Answer
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Fracturing and assim...
View Answer

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The ultramafic rock composed predominantly of is known as peridotite and is likely the rock that makes up the part of Earth known as the .

Correct Answer
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olivine,up...
View Answer

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Correct Answer
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Most batholiths appear to have...
View Answer

Correct Answer
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Pegmatites are extremely coarse-grained granitic rocks which form as dikes,sills,and stocks from the cooling of the liquid-vapor-rich phases of felsic magmas.

Correct Answer
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Laccoliths

Correct Answer
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Rapid cooling of magma results in a(n) grained texture called .

Correct Answer
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Correct Answer
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Mantle plumes are responsible for linear...
View Answer

Correct Answer
verified

Correct Answer
verified
Both are near-surfac...
View Answer

Correct Answer
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D

Correct Answer
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Correct Answer
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Correct Answer
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The magma ...
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Correct Answer
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Felsic rocks melt at...
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