Question 1

Pegmatites,which occur in dikes,are unusual among shallow intrusive rocks in that they ____________.

Accepted Answer

A) possess porphyritic texture 
B) possess exceptionally coarse grains 
C) are mineralogically identical to the extrusive rock basalt 
D) are glassy,cooling so rapidly that crystals do not have time to form 
A) possess porphyritic texture 
B) possess exceptionally coarse grains 
C) are mineralogically identical to the extrusive rock basalt 
D) are glassy,cooling so rapidly that crystals do not have time to form

Question 2

Consult the figure below.If you found tuff deposits at an ___________ igneous setting,you could conclude that the lava had a ___________ viscosity content.

Accepted Answer

A) intrusive;high 
B) intrusive;low 
C) extrusive;high 
D) extrusive;low 
A) intrusive;high 
B) intrusive;low 
C) extrusive;high 
D) extrusive;low

Question 3

Due to fractional crystallization and assimilation of surrounding host rock,most magmas that rise slowly through the crust chemically evolve to become ____________.

Accepted Answer

A) more felsic 
B) more mafic 
C) dominated by nonsilicate minerals 
A) more felsic 
B) more mafic 
C) dominated by nonsilicate minerals

Question 4

The difference between lava and magma is that magma ____________.

Accepted Answer

A) is light in color,whereas lava is dark 
B) usually has mafic composition,whereas lava usually has felsic composition 
C) is found beneath the Earth's surface,whereas lava has reached the surface 
D) flows more quickly than lava 
A) is light in color,whereas lava is dark 
B) usually has mafic composition,whereas lava usually has felsic composition 
C) is found beneath the Earth's surface,whereas lava has reached the surface 
D) flows more quickly than lava

Question 5

Vesicles are a term used to describe a texture in __________ igneous rocks.

Accepted Answer

A) crystalline 
B) glassy 
C) pyroclastic 
A) crystalline 
B) glassy 
C) pyroclastic

Question 6

If a body of magma becomes more felsic,its viscosity will ____________.

Accepted Answer

A) increase 
B) decrease 
C) stay the same 
A) increase 
B) decrease 
C) stay the same

Question 7

Consult the figure below.A dike is a(n)____________.

Accepted Answer

A) sheet-like intrusion that lies parallel to surrounding layers of sedimentary rock 
B) cooled layer of lava 
C) intrusion formed within the magma chamber of a volcano 
D) sheet-like intrusion that cuts across preexisting layers 
A) sheet-like intrusion that lies parallel to surrounding layers of sedimentary rock 
B) cooled layer of lava 
C) intrusion formed within the magma chamber of a volcano 
D) sheet-like intrusion that cuts across preexisting layers

Question 8

In Bowen's discontinuous reaction series,the first mineral to crystallize from a mafic melt is ____________.

Accepted Answer

A) olivine 
B) plagioclase 
C) pyroxene 
D) quartz 
A) olivine 
B) plagioclase 
C) pyroxene 
D) quartz

Question 9

Volcanoes that do NOT occur along either present or emergent plate boundaries are associated with ____________.

Accepted Answer

A) continental rifts 
B) mantle hot spots 
C) mid-ocean ridges 
D) subduction zones 
A) continental rifts 
B) mantle hot spots 
C) mid-ocean ridges 
D) subduction zones

Question 10

Obsidian,shown below,____________.

Accepted Answer

A) is volcanic glass 
B) possesses conchoidal fracture 
C) typically is felsic in composition 
D) All of the above are correct. 
A) is volcanic glass 
B) possesses conchoidal fracture 
C) typically is felsic in composition 
D) All of the above are correct.

Question 11

Geologically,melts are equivalent to both ____________ and ____________.

Accepted Answer

A) felsic magma;mafic magma 
B) felsic lava;mafic lava 
C) lavas;magmas 
D) fine-grained igneous rocks;coarse-grained igneous rocks 
A) felsic magma;mafic magma 
B) felsic lava;mafic lava 
C) lavas;magmas 
D) fine-grained igneous rocks;coarse-grained igneous rocks

Question 12

As compared to coarse-grained igneous rocks,all fine-grained igneous rocks ____________.

Accepted Answer

A) cool and solidify more quickly 
B) cool and solidify more slowly 
C) solidify at higher temperatures 
D) solidify at lower temperatures 
A) cool and solidify more quickly 
B) cool and solidify more slowly 
C) solidify at higher temperatures 
D) solidify at lower temperatures

Question 13

Coarse-grained granite is most similar in mineral composition to fine-grained ____________.

Accepted Answer

A) andesite 
B) basalt 
C) komatiite 
D) rhyolite 
A) andesite 
B) basalt 
C) komatiite 
D) rhyolite

Question 14

Viscosity depends on ____________.

Accepted Answer

A) temperature 
B) volatile content 
C) silica content 
D) All of the above are correct. 
A) temperature 
B) volatile content 
C) silica content 
D) All of the above are correct.

Question 15

Large igneous provinces are formed by ___________,which can flow tens to hundreds of kilometers.

Accepted Answer

A) flood basalts 
B) sills 
C) super plumes 
D) None of the above are correct. 
A) flood basalts 
B) sills 
C) super plumes 
D) None of the above are correct.

Question 16

If a body of igneous (source)rock is subjected to partial melting,the magma that is produced is expected to be ____________.

Accepted Answer

A) identical in chemical composition to the source rock 
B) more mafic than the source rock 
C) more felsic than the source rock 
A) identical in chemical composition to the source rock 
B) more mafic than the source rock 
C) more felsic than the source rock

Question 17

In regard to the cooling of molten rock,a __________ volume and a __________ shape cools faster.

Accepted Answer

A) larger;spherical 
B) larger;pancake 
C) smaller;spherical 
D) smaller;pancake 
A) larger;spherical 
B) larger;pancake 
C) smaller;spherical 
D) smaller;pancake

Question 18

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) have a tendency to evaporate and are stable as gases 
A) crystallize most rapidly out of a melt 
B) melt immediately upon contact with a hot body of magma 
C) have a tendency to evaporate and are stable as gases

Question 19

Mt.Kilimanjaro and the Basin and Range Province are the result of _____________.

Accepted Answer

A) converging plates 
B) subducting plates 
C) rifting 
D) None of the above are correct. 
A) converging plates 
B) subducting plates 
C) rifting 
D) None of the above are correct.

Question 20

Which of the following is NOT a factor controlling the cooling rate of magma?

Accepted Answer

A) depth of intrusion 
B) shape and size of magma body 
C) presence of circulating groundwater 
D) All of the above are factors. 
A) depth of intrusion 
B) shape and size of magma body 
C) presence of circulating groundwater 
D) All of the above are factors.

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

Pegmatites,which occur in dikes,are unusual among shallow intrusive rocks in that they ____________.

Consult the figure below.If you found tuff deposits at an ___________ igneous setting,you could conclude that the lava had a ___________ viscosity content.

Due to fractional crystallization and assimilation of surrounding host rock,most magmas that rise slowly through the crust chemically evolve to become ____________.

The difference between lava and magma is that magma ____________.

Vesicles are a term used to describe a texture in __________ igneous rocks.

If a body of magma becomes more felsic,its viscosity will ____________.

Consult the figure below.A dike is a(n)____________.

In Bowen's discontinuous reaction series,the first mineral to crystallize from a mafic melt is ____________.

Volcanoes that do NOT occur along either present or emergent plate boundaries are associated with ____________.

Obsidian,shown below,____________.

Geologically,melts are equivalent to both ____________ and ____________.

As compared to coarse-grained igneous rocks,all fine-grained igneous rocks ____________.

Coarse-grained granite is most similar in mineral composition to fine-grained ____________.

Viscosity depends on ____________.

Large igneous provinces are formed by ___________,which can flow tens to hundreds of kilometers.

If a body of igneous (source)rock is subjected to partial melting,the magma that is produced is expected to be ____________.

In regard to the cooling of molten rock,a __________ volume and a __________ shape cools faster.

Volatiles refer to substances that ____________.

Mt.Kilimanjaro and the Basin and Range Province are the result of _____________.

Which of the following is NOT a factor controlling the cooling rate of magma?

Cosmology and the Birth of Earth

Journey to the Center of the Earth

Drifting Continents and Spreading Seas

The Way the Earth Works: Plate Tectonics

Patterns in Nature: Minerals

Pages of Earths Past: Sedimentary Rocks

Metamorphism: A Process of Change

The Wrath of Vulcan: Volcanic Eruptions

A Violent Pulse: Earthquakes

Cracks, crags, and Crumples: Crustal Deformation and Mountain Building

Deep Time: How Old Is Old

A Biography of Earth

Squeezing Power From a Stone: Energy Resources

Riches in Rock: Mineral Resources

Unsafe Ground: Landslides and Other Mass Movements

Streams and Floods: The Geology of Running Water

Restless Realm: Oceans and Coasts

A Hidden Reserve: Groundwater

An Envelope of Gas: Earths Atmosphere and Climate

Dry Settings: the Geology of Deserts

Amazing Ice: Glaciers and Ice Ages

Global Change in the Earth System

Filters

Consult the figure below.If you found tuff deposits at an _ igneous setting,you could conclude that the lava had a _ viscosity content.

Geologically,melts are equivalent to both and .

In regard to the cooling of molten rock,a volume and a shape cools faster.