Question 1

Note the image showing a series of batholiths on the landscape. How did those batholiths get exposed at the surface?

Accepted Answer

A)   The batholiths were washed downhill from distant mountains and deposited here.
B)   Batholiths crystallize below the surface but then flow upwards towards the surface.
C)   Batholiths crystallize at the surface, so they are simply still in place.
D)   Batholiths crystallize below the surface but were later exposed by way of erosion of overlying material.E) A) and D)
F) B) and C)

Question 2

What is the connection between the amount of silica in a melt and how viscous it is?

Accepted Answer

A)   Higher silica content lowers the melting temperature and since increasing the temperature of a magma decreases viscosity increasing silica content increases viscosity.
B)   Silica forms strong bonds, so higher amounts of silica make for more viscous magma.
C)   Higher silica content means a larger amount of water a magma can dissolve and water decreases magma viscosity, so increasing silica content decreases magma viscosity.
D)   There is no correlation between silica content and magma viscosity.E) B) and D)
F) C) and D)

Question 3

Pyroclastic flows move_______ .

Accepted Answer

A)   as gravity flows similar to snow avalanches
B)   very rapidly, too fast to outrun on foot
C)   as a dense cloud that contains hot magma particles suspended in hot gases and moves rapidly downhill
D)   all of the above
E)   none of the aboveF) A) and D)
G) A) and C)

Question 4

The rock pumice often floats yet the density of the rock is greater than water. Why does it float?

Accepted Answer

A)   Pumice is a rock made of rhyolite glass that erupts into water, which traps water in voids and makes the material less dense than water.
B)   Pumice is a pyroclastic rock comprised largely of open voids formed by gases released when the magma solidified as froth- like material.
C)   Pumice is another name for dacite, a low- density rock that floats in water.
D)   Pumice is a pyroclastic rock derived from rhyolite glass, and rhyolite glass has a lower density than water.E) A) and C)
F) None of the above

Question 5

The main mechanism for melting at spreading ridges is_______ .

Accepted Answer

A)   surficial melting of sedimentary rock
B)   subduction produced andesitic magmas
C)   decompression melting of ultramafic mantle rock
D)   large scale melting of rhyolitic core rockE) None of the above
F) A) and D)

Question 6

Match the letter on the figure with the term.
 
-Identify what letter B represents in the diagram.

Accepted Answer

A)   bomb
B)   lava flow
C)   magma chamber
D)   vent
E)   pyroclastic materialF) A) and E)
G) None of the above

Question 7

The average composition of rocks comprising a large composite cone or stratovolcano is generally_______ .

Accepted Answer

A)   andesitic
B)   ultramafic
C)   rhyolitic
D)   basalticE) B) and C)
F) B) and D)

Question 8

The famous destruction of the Roman city of Pompeii was produced by_______ .

Accepted Answer

A)   a volcanic mudflow from Mt. Vesuvius that buried the people and the city
B)   a composite volcano erupted lava that buried the city, fossilizing people who were overridden by the fast moving flows
C)   a large cinder cone burying the city in tephra
D)   a pyroclastic eruption from a composite volcano that buried the city in ash and smothered the people living thereE) B) and C)
F) A) and B)

Question 9

Where can we find the most active volcanoes in the world?

Accepted Answer

A)   Italy
B)   Hawaii
C)   Washington State
D)   MexicoE) B) and D)
F) B) and C)

Question 10

Magmas are generated at mid- ocean ridges by _______melting.

Accepted Answer

A)   compression
B)   hot spot
C)   subductional
D)   decompressionE) B) and C)
F) A) and D)

Question 11

Paricutin volcano in Mexico is an example of a _______ .

Accepted Answer

A)   lava dome
B)   shield volcano
C)   composite volcano
D)   cinder coneE) All of the above
F) C) and D)

Question 12

Match the letter on the figure with the term.
 
-Identify what letter A represents in the diagram.

Accepted Answer

A)   bomb
B)   lava flow
C)   magma chamber
D)   vent
E)   pyroclastic materialF) D) and E)
G) A) and E)

Question 13

What type of volcanic material is indicative of eruption under water?

Accepted Answer

A)   Aa flows
B)   Pillow lavas
C)   Pyroclastic flows
D)   Pahoehoe flows
E)   Lava apronsF) C) and D)
G) All of the above

Question 14

_______is the major dissolved volatile constituent in both magmas and volcanic gases.

Accepted Answer

A)   Hydrogen chloride
B)   Carbon monoxide
C)   Methane
D)   WaterE) All of the above
F) B) and C)

Question 15

Dissolved gases may comprise up to_______ of a magma.

Accepted Answer

A)   about half
B)   all of
C)   most of
D)   a few percent ofE) C) and D)
F) A) and B)

Question 16

Which of the following best describes Shiprock, a famous volcanic feature in New Mexico?

Accepted Answer

A)   an extinct, highly symmetrical, composite volcanic cone
B)   an extinct, massive, rhyolitic shield volcano
C)   a very recently active, basaltic cinder cone
D)   the eroded remains of a volcanic pipe and radiating dikesE) C) and D)
F) A) and B)

Question 17

Volcanoes are generally not preserved in the geologic rock record because the upper part of the volcano is eroded away. However, the igneous rocks associated with volcanoes are often found preserved in the rock record as layers of volcanic rock and associated intrusions. How could you infer what type of volcano erupted in a given area based on the type of volcanic deposits? Give specific examples and briefly discuss if some materials may be linked to different types of volcanoes.

Accepted Answer

The answers to this question could vary,...

Question 18

In what plate tectonic setting are magmas generated predominantly by fluids from ocean waters in trenches "fluxing" the melting process by decreasing melting temperature?

Accepted Answer

A)   transform faults
B)   hot spots
C)   convergent plate margins
D)   spreading ridgesE) A) and B)
F) A) and C)

Question 19

Which of the following is considered pyroclastic debris?

Accepted Answer

A)   aa
B)   water vapor
C)   volcanic ash
D)   pahoehoeE) B) and C)
F) All of the above

Question 20

The viscosities of magmas _______with increasing percentages of silica.

Accepted Answer

A)   increase
B)   decrease
C)   are unrelatedD) All of the above
E) A) and B)

Exam 6: Volcanoes and Other Igneous Activity

Paricutin volcano in Mexico is an example of a _______ .

Correct Answer
verified

Where can we find the most active volcanoes in the world?

Correct Answer
verified

What type of volcanic material is indicative of eruption under water?

Correct Answer
verified

In what plate tectonic setting are magmas generated predominantly by fluids from ocean waters in trenches "fluxing" the melting process by decreasing melting temperature?

Correct Answer
verified

The rock pumice often floats yet the density of the rock is greater than water. Why does it float?

Correct Answer
verified

Which of the following best describes Shiprock, a famous volcanic feature in New Mexico?

Correct Answer
verified

The main mechanism for melting at spreading ridges is_______ .

Correct Answer
verified

Match the letter on the figure with the term. -Identify what letter B represents in the diagram.

Correct Answer
verified

Pyroclastic flows move_______ .

Correct Answer
verified

The average composition of rocks comprising a large composite cone or stratovolcano is generally_______ .

Correct Answer
verified

Note the image showing a series of batholiths on the landscape. How did those batholiths get exposed at the surface?

Correct Answer
verified

The viscosities of magmas _______with increasing percentages of silica.

Correct Answer
verified

Dissolved gases may comprise up to_______ of a magma.

Correct Answer
verified

Correct Answer
verified
The answers to this question could vary,...
View Answer

What is the connection between the amount of silica in a melt and how viscous it is?

Correct Answer
verified

_______is the major dissolved volatile constituent in both magmas and volcanic gases.

Correct Answer
verified

The famous destruction of the Roman city of Pompeii was produced by_______ .

Correct Answer
verified

Which of the following is considered pyroclastic debris?

Correct Answer
verified

Magmas are generated at mid- ocean ridges by _______melting.

Correct Answer
verified

Match the letter on the figure with the term. -Identify what letter A represents in the diagram.

Correct Answer
verified

Exam 6: Volcanoes and Other Igneous Activity

Paricutin volcano in Mexico is an example of a _______ .

Correct AnswerverifiedShow Answer

Where can we find the most active volcanoes in the world?

Correct AnswerverifiedShow Answer

What type of volcanic material is indicative of eruption under water?

Correct AnswerverifiedShow Answer

In what plate tectonic setting are magmas generated predominantly by fluids from ocean waters in trenches "fluxing" the melting process by decreasing melting temperature?

Correct AnswerverifiedShow Answer

The rock pumice often floats yet the density of the rock is greater than water. Why does it float?

Correct AnswerverifiedShow Answer

Which of the following best describes Shiprock, a famous volcanic feature in New Mexico?

Correct AnswerverifiedShow Answer

The main mechanism for melting at spreading ridges is_______ .

Correct AnswerverifiedShow Answer

Match the letter on the figure with the term. -Identify what letter B represents in the diagram.

Correct AnswerverifiedShow Answer

Pyroclastic flows move_______ .

Correct AnswerverifiedShow Answer

The average composition of rocks comprising a large composite cone or stratovolcano is generally_______ .

Correct AnswerverifiedShow Answer

Note the image showing a series of batholiths on the landscape. How did those batholiths get exposed at the surface?

Correct AnswerverifiedShow Answer

The viscosities of magmas _______with increasing percentages of silica.

Correct AnswerverifiedShow Answer

Dissolved gases may comprise up to_______ of a magma.

Correct AnswerverifiedShow Answer

Correct AnswerverifiedThe answers to this question could vary,...View AnswerShow Answer

What is the connection between the amount of silica in a melt and how viscous it is?

Correct AnswerverifiedShow Answer

_______is the major dissolved volatile constituent in both magmas and volcanic gases.

Correct AnswerverifiedShow Answer

The famous destruction of the Roman city of Pompeii was produced by_______ .

Correct AnswerverifiedShow Answer

Which of the following is considered pyroclastic debris?

Correct AnswerverifiedShow Answer

Magmas are generated at mid- ocean ridges by _______melting.

Correct AnswerverifiedShow Answer

Match the letter on the figure with the term. -Identify what letter A represents in the diagram.

Correct AnswerverifiedShow Answer

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified
The answers to this question could vary,...
View Answer

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified