Question 1

A volcanic neck,such as that seen at Shiprock,New Mexico (below),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 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 a volcano 
D)  sheet-like intrusion that cuts across preexisting layers

Question 2

Bombs,ash,and cinders are all examples of ____________.

Accepted Answer

A)  intrusive igneous rocks 
B)  hot spots 
C)  volatiles 
D)  pyroclastic debris 
A)  intrusive igneous rocks 
B)  hot spots 
C)  volatiles 
D)  pyroclastic debris

Question 3

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) 
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)

Question 4

A majority of the melts in the Earth form through the partial melting of ultramafic mantle rock.These newly formed magmas are ____________.

Accepted Answer

A)  ultramafic 
B)  mafic 
C)  felsic 
D)  intermediate 
A)  ultramafic 
B)  mafic 
C)  felsic 
D)  intermediate

Question 5

Bowen's continuous reaction series describes the crystallization behavior of a single mineral (with variable chemical composition),____________.

Accepted Answer

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

Question 6

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

Accepted Answer

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

Question 7

A volcanic island arc occurs at ____________.

Accepted Answer

A)  the Aleutian Islands of Alaska 
B)  the Andes Mountains 
C)  Hawaii 
D)  Mt. St. Helens, Washington 
A)  the Aleutian Islands of Alaska 
B)  the Andes Mountains 
C)  Hawaii 
D)  Mt. St. Helens, Washington

Question 8

Which of the following would help distinguish continental hot spots from oceanic hot spots?

Accepted Answer

A)  the presence of water 
B)  the presence of both mafic and felsic magmas 
C)  the presence of other, extinct or active, volcanoes nearby 
D)  the presence of basalt 
A)  the presence of water 
B)  the presence of both mafic and felsic magmas 
C)  the presence of other, extinct or active, volcanoes nearby 
D)  the presence of basalt

Question 9

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 10

Why don't all igneous rocks contain all the minerals listed in Bowen's Reaction Series?

Accepted Answer

A)  Minerals degrade with time, leaving only some of the series behind in igneous rocks. 
B)  Crystallization may be complete before all of the minerals in the series have had time to form. 
C)  Not all of the minerals in the series have the ability to form in every rock. 
D)  Bowen's Reaction Series only applies to some igneous rocks, not all. 
A)  Minerals degrade with time, leaving only some of the series behind in igneous rocks. 
B)  Crystallization may be complete before all of the minerals in the series have had time to form. 
C)  Not all of the minerals in the series have the ability to form in every rock. 
D)  Bowen's Reaction Series only applies to some igneous rocks, not all.

Question 11

Pillow basalts,shown below,attain their distinctive blob-like shapes because their parent lavas do not travel far prior to solidification.This is because the parent lavas ____________.

Accepted Answer

A)  are completely devoid of volatiles and thus travel slowly 
B)  erupt underwater and thus cool very quickly 
C)  are highly felsic and thus travel slowly 
D)  are ultramafic and thus freeze at exceptionally high temperatures 
A)  are completely devoid of volatiles and thus travel slowly 
B)  erupt underwater and thus cool very quickly 
C)  are highly felsic and thus travel slowly 
D)  are ultramafic and thus freeze at exceptionally high temperatures

Question 12

As compared to mafic igneous rocks,all felsic 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

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 14

If you determine the composition of an igneous rock,you can deduce a number of things about the rock's origin.Which one of these is NOT one of those things?

Accepted Answer

A)  the rate at which it cooled 
B)  the environment in which it formed 
C)  the original source of the magma 
D)  the exact age of the rock 
A)  the rate at which it cooled 
B)  the environment in which it formed 
C)  the original source of the magma 
D)  the exact age of the rock

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)  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 16

A famous example of hot-spot volcanism occurs at ____________.

Accepted Answer

A)  the Aleutian Islands of Alaska 
B)  the Andes Mountains 
C)  the island of Hawaii 
D)  Mt. St. Helens, Washington 
A)  the Aleutian Islands of Alaska 
B)  the Andes Mountains 
C)  the island of Hawaii 
D)  Mt. St. Helens, Washington

Question 17

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

Accepted Answer

A)  porphyritic 
B)  phaneritic 
C)  aphanitic 
D)  necrotic 
A)  porphyritic 
B)  phaneritic 
C)  aphanitic 
D)  necrotic

Question 18

The geotherm is the rate of change of ____________.

Accepted Answer

A)  pressure with depth in Earth's interior 
B)  temperature with depth in Earth's interior 
C)  temperature with altitude in Earth's atmosphere 
D)  temperature with latitude on Earth's surface 
A)  pressure with depth in Earth's interior 
B)  temperature with depth in Earth's interior 
C)  temperature with altitude in Earth's atmosphere 
D)  temperature with latitude on Earth's surface

Question 19

Stoping by magmas occurs when ____________.

Accepted Answer

A)  pieces of surrounding country rock are broken off and assimilated 
B)  the magma stops flowing and starts to solidify 
C)  the magma becomes fully solidified to form intrusive rock 
D)  the magma alters a thin rind of surrounding country rock 
A)  pieces of surrounding country rock are broken off and assimilated 
B)  the magma stops flowing and starts to solidify 
C)  the magma becomes fully solidified to form intrusive rock 
D)  the magma alters a thin rind of surrounding country rock

Question 20

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 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 Earth's surface, whereas lava has reached the surface 
D)  flows more quickly than lava

Exam 4: Up From the Inferno: Magma and Igneous Rocks

A volcanic neck,such as that seen at Shiprock,New Mexico (below),is a(n)____________.

Bombs,ash,and cinders are all examples of ____________.

When rock is partially melted,the chemistry of the melt is ____________.

A majority of the melts in the Earth form through the partial melting of ultramafic mantle rock.These newly formed magmas are ____________.

Bowen's continuous reaction series describes the crystallization behavior of a single mineral (with variable chemical composition),____________.

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

A volcanic island arc occurs at ____________.

Which of the following would help distinguish continental hot spots from oceanic hot spots?

Viscosity depends on ____________.

Why don't all igneous rocks contain all the minerals listed in Bowen's Reaction Series?

Pillow basalts,shown below,attain their distinctive blob-like shapes because their parent lavas do not travel far prior to solidification.This is because the parent lavas ____________.

As compared to mafic igneous rocks,all felsic igneous rocks ____________.

Geologically,melts are equivalent to both ____________ and ____________.

If you determine the composition of an igneous rock,you can deduce a number of things about the rock's origin.Which one of these is NOT one of those things?

Volatiles refer to substances that ____________.

A famous example of hot-spot volcanism occurs at ____________.

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

The geotherm is the rate of change of ____________.

Stoping by magmas occurs when ____________.

The difference between lava and magma is that magma ____________.

The Earth in Context

The Way the Earth Works: Plate Tectonics

Patterns in Nature: Minerals

The Wrath of Vulcan: Volcanic Eruptions

Pages of Earths Past: Sedimentary Rocks

Metamorphism: a Process of Change

A Violent Pulse: Earthquakes

Crags, cracks, and Crumples: Crustal Deformation and Mountain Building

Deep Time: How Old Is Old

A Biography of Earth

Riches in Rock: Energy and 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

Dry Regions: the Geology of Deserts

Amazing Ice: Glaciers and Ice Ages

Global Change in the Earth System

Rock Groups

A Surface Veneer: Sediments and Soils

The Rock Cycle

The Earths Interior Revisited: Insights From Geophysics

Memories of Past Life: Fossils and Evolution

An Introduction to Landscapes and the Hydrologic Cycle

Filters

Geologically,melts are equivalent to both and .