Question 1

Match the description with the appropriate texture
-____________magma cools and consolidates without growth of mineral grains

Accepted Answer

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

Question 2

What name would you assign to a dense phaneritic green rock having olivine and pyroxene as dominant minerals?

Accepted Answer

A)  gabbro 
B)  granite 
C)  diorite 
D)  peridotite 
A)  gabbro 
B)  granite 
C)  diorite 
D)  peridotite

Question 3

A____________ is an open cavity in a volcanic rock that was filled by a gas bubble when the lava was still mainly liquid.

Accepted Answer

A)  xenocryst 
B)  porphyrocryst 
C)  vesicle 
D)  phenocryst 
A)  xenocryst 
B)  porphyrocryst 
C)  vesicle 
D)  phenocryst

Question 4

Which of the following igneous rocks is composed mainly of ferromagnesian minerals with less than 20% feldspar?

Accepted Answer

A)  granite 
B)  rhyolite 
C)  andesite 
D)  peridotite 
A)  granite 
B)  rhyolite 
C)  andesite 
D)  peridotite

Question 5

The aphanitic equivalent of granite is

Accepted Answer

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

Question 6

What phenocryst minerals would you expect to find in an aphanitic rhyolite flow?

Accepted Answer

A)  quartz and K- feldspar 
B)  apatite and muscovite 
C)  intermediate (Ca- Na) plagioclase and amphibole or pyroxene 
D)  Ca- rich plagioclase and olivine 
A)  quartz and K- feldspar 
B)  apatite and muscovite 
C)  intermediate (Ca- Na) plagioclase and amphibole or pyroxene 
D)  Ca- rich plagioclase and olivine

Question 7

In a porphyritic volcanic rock, which mineral grains are the last to crystallize?

Accepted Answer

A)  vesicles 
B)  phenocrysts 
C)  matrix or groundmass 
D)  pegmatites 
A)  vesicles 
B)  phenocrysts 
C)  matrix or groundmass 
D)  pegmatites

Question 8

The last minerals to crystallize in Bowen's reaction series result in igneous rocks with a ________composition.

Accepted Answer

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

Question 9

________is a volcanic rock that is extremely vesicular and glassy.

Accepted Answer

A)  Pumice 
B)  Pegmatite 
C)  Tuff 
D)  Obsidian 
A)  Pumice 
B)  Pegmatite 
C)  Tuff 
D)  Obsidian

Question 10

Rocks that consist completely of disordered ions with no long range structures are called ________.

Accepted Answer

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

Question 11

Which of the following high silica igneous rocks can be of low enough density to float on water?

Accepted Answer

A)  obsidian 
B)  granite 
C)  rhyolite 
D)  pumice 
A)  obsidian 
B)  granite 
C)  rhyolite 
D)  pumice

Question 12

What is/are thought to be the main mechanism(s) for generating basaltic melts from hot peridotite near its melting point in the upper mantle?

Accepted Answer

A)  drop of confining pressure or introduction of water 
B)  frictional heating of basaltic ocean crust as it slides down subduction zones 
C)  intrusion of hotter solid mantle rocks from below 
D)  conductive heating of basaltic ocean crust subducted into the mantle 
A)  drop of confining pressure or introduction of water 
B)  frictional heating of basaltic ocean crust as it slides down subduction zones 
C)  intrusion of hotter solid mantle rocks from below 
D)  conductive heating of basaltic ocean crust subducted into the mantle

Question 13

Which of the following are used for studying rocks with a polarizing microscope?

Accepted Answer

A)  polished cubes 
B)  thin sections 
C)  broken chips 
D)  grain karats 
A)  polished cubes 
B)  thin sections 
C)  broken chips 
D)  grain karats

Question 14

Lava flows are typically finer grained than intrusive igneous rocks. Why?

Accepted Answer

A)  Intrusive magma is cooler because it is well insulated by the surrounding rock. 
B)  The extrusive magma, because it is deep below the surface, cools very slowly producing very small mineral grains. 
C)  Intrusive magma flows onto the Earth's surface and cools very slowly, allowing many small mineral grains to grow. 
D)  The extrusive magma cools quickly so the mineral grains do not have time to grow. 
A)  Intrusive magma is cooler because it is well insulated by the surrounding rock. 
B)  The extrusive magma, because it is deep below the surface, cools very slowly producing very small mineral grains. 
C)  Intrusive magma flows onto the Earth's surface and cools very slowly, allowing many small mineral grains to grow. 
D)  The extrusive magma cools quickly so the mineral grains do not have time to grow.

Question 15

What igneous rock is named for a prominent, volcanic mountain range in western South America?

Accepted Answer

A)  peridotite 
B)  andesite 
C)  basalt 
D)  pegmatite 
A)  peridotite 
B)  andesite 
C)  basalt 
D)  pegmatite

Question 16

98% of most common crustal igneous rocks are made of __________.

Accepted Answer

A)  titanium, manganese, gold, silver, and uranium 
B)  oxygen, silicon, aluminum, calcium, sodium, potassium, magnesium, and iron 
C)  oxygen, hydrogen, nitrogen carbon, and sulfur 
D)  lithium, cesium, uranium, and rare earths 
A)  titanium, manganese, gold, silver, and uranium 
B)  oxygen, silicon, aluminum, calcium, sodium, potassium, magnesium, and iron 
C)  oxygen, hydrogen, nitrogen carbon, and sulfur 
D)  lithium, cesium, uranium, and rare earths

Question 17

What weight percentage of silica (SiO2) typifies granites and rhyolites?

Accepted Answer

A)  90% 
B)  50% 
C)  30% 
D)  70% 
A)  90% 
B)  50% 
C)  30% 
D)  70%

Question 18

Which process describes how the removal and isolation of early- formed mineral grains can cause the composition of the remaining magma to change?

Accepted Answer

The answer of Which process describes how the removal and...

Question 19

All of the following are factors that affect the generation of magma except for__________ .

Accepted Answer

A)  heat 
B)  crystal size 
C)  volatiles 
D)  pressure 
A)  heat 
B)  crystal size 
C)  volatiles 
D)  pressure

Question 20

Xenoliths are likely to be associated with which magmatic process and igneous rock body?

Accepted Answer

A)  magmatic differentiation; gabbro sill 
B)  intrusion; granitic batholith 
C)  flattening; welded ash flow tuffs 
D)  columnar jointing; lava flow 
A)  magmatic differentiation; gabbro sill 
B)  intrusion; granitic batholith 
C)  flattening; welded ash flow tuffs 
D)  columnar jointing; lava flow

Match the description with the appropriate texture -____________magma cools and consolidates without growth of mineral grains

What name would you assign to a dense phaneritic green rock having olivine and pyroxene as dominant minerals?

A____________ is an open cavity in a volcanic rock that was filled by a gas bubble when the lava was still mainly liquid.

Which of the following igneous rocks is composed mainly of ferromagnesian minerals with less than 20% feldspar?

The aphanitic equivalent of granite is

What phenocryst minerals would you expect to find in an aphanitic rhyolite flow?

In a porphyritic volcanic rock, which mineral grains are the last to crystallize?

The last minerals to crystallize in Bowen's reaction series result in igneous rocks with a ________composition.

________is a volcanic rock that is extremely vesicular and glassy.

Rocks that consist completely of disordered ions with no long range structures are called ________.

Which of the following high silica igneous rocks can be of low enough density to float on water?

What is/are thought to be the main mechanism(s) for generating basaltic melts from hot peridotite near its melting point in the upper mantle?

Which of the following are used for studying rocks with a polarizing microscope?

Lava flows are typically finer grained than intrusive igneous rocks. Why?

What igneous rock is named for a prominent, volcanic mountain range in western South America?

98% of most common crustal igneous rocks are made of __________.

What weight percentage of silica (SiO2) typifies granites and rhyolites?

Which process describes how the removal and isolation of early- formed mineral grains can cause the composition of the remaining magma to change?

All of the following are factors that affect the generation of magma except for__________ .

Xenoliths are likely to be associated with which magmatic process and igneous rock body?

An Introduction to Geology and Plate Tectonics

Minerals: the Building Blocks of Rocks

Igneous Rocks

Volcanoes and Volcanic Processes

Weathering and Soil

Sedimentary Rocks

Metamorphism and Metamorphic Rocks

Geologic Time

Crustal Deformation

Earthquakes and Earths Interior

The Ocean Floor

Plate Tectonics: the Framework for Modern Geology

Mountain Building and Continental Frameworks

Running Water

Groundwater

Glaciers and Glaciation

Deserts and Winds

Shorelines

Mineral and Energy Resources

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Exam 14: Mass Wasting: the Work of Gravity

Match the description with the appropriate texture -____________magma cools and consolidates without growth of mineral grains

What name would you assign to a dense phaneritic green rock having olivine and pyroxene as dominant minerals?

A____________ is an open cavity in a volcanic rock that was filled by a gas bubble when the lava was still mainly liquid.

Which of the following igneous rocks is composed mainly of ferromagnesian minerals with less than 20% feldspar?

The aphanitic equivalent of granite is

What phenocryst minerals would you expect to find in an aphanitic rhyolite flow?

In a porphyritic volcanic rock, which mineral grains are the last to crystallize?

The last minerals to crystallize in Bowen's reaction series result in igneous rocks with a ________composition.

________is a volcanic rock that is extremely vesicular and glassy.

Rocks that consist completely of disordered ions with no long range structures are called ________.

Which of the following high silica igneous rocks can be of low enough density to float on water?

What is/are thought to be the main mechanism(s) for generating basaltic melts from hot peridotite near its melting point in the upper mantle?

Which of the following are used for studying rocks with a polarizing microscope?

Lava flows are typically finer grained than intrusive igneous rocks. Why?

What igneous rock is named for a prominent, volcanic mountain range in western South America?

98% of most common crustal igneous rocks are made of __________.

What weight percentage of silica (SiO2) typifies granites and rhyolites?

Which process describes how the removal and isolation of early- formed mineral grains can cause the composition of the remaining magma to change?

All of the following are factors that affect the generation of magma except for__________ .

Xenoliths are likely to be associated with which magmatic process and igneous rock body?

An Introduction to Geology and Plate Tectonics

Minerals: the Building Blocks of Rocks

Igneous Rocks

Volcanoes and Volcanic Processes

Weathering and Soil

Sedimentary Rocks

Metamorphism and Metamorphic Rocks

Geologic Time

Crustal Deformation

Earthquakes and Earths Interior

The Ocean Floor

Plate Tectonics: the Framework for Modern Geology

Mountain Building and Continental Frameworks

Running Water

Groundwater

Glaciers and Glaciation

Deserts and Winds

Shorelines

Mineral and Energy Resources

Filters