GL101 Exam Review 2025 Questions and
Answers Verified 100% Correct
All silicate minerals contain which two elements?
A) iron, silicon
B) silicon, sodium
C) oxygen, carbon
D) silicon, oxygen - ANSWER -D
All ferromagnesian minerals contain which two elements?
A) calcium, sodium
B) iron, magnesium
C) iron, potassium
D) chlorine, silicon - ANSWER -B
Which mineral is composed of silicon dioxide (SiO2)?
A) calcite
B) diamond
C) olivine
D) quartz - ANSWER -D
Why doesn't quartz have any cleavages, only fractures?
A) All oxygens are shared between strongly bonded silicons in a 3-D framework.
B) All of the metallic cations form strong webs between the silicate chains.
C) It is made of pure silicon which is very strong.
D) It has strong helical chains in three perpendicular directions. - ANSWER -A
Silicate igneous rocks make up the ________.
A) bulk of volcanic mountains but not much else on Earth
B) bulk of the Earth's crust and mantle
C) densest rocks and are mainly found in the core
,D) majority of shallow rocks covering the continents but everything deeper is
sedimentary and metamorphic - ANSWER -B
Three processes contribute to the formation of every igneous rock: ________.
A) assimilation, crystallization, and dyke injection
B) extrusion, intrusion, and consolidation
C) partial melting, buoyant rise, and crystallization
D) volcanism, plutonism, and magmatic differentiation - ANSWER -C
Plutonic rocks are emplaced at depth yet they can be seen at the Earth's surface
due mainly to
A) catastrophic violent upheavals that bring them to the surface
B) continual ongoing intrusion after the magma solidifies
C) erosion of overlying rocks due to uplift
D) widespread igneous inversion - ANSWER -C
Which of the following is the major dissolved volatile constituent in both magmas
and volcanic gases?
A) carbon monoxide
B) methane
C) nitrous oxide
D) water - ANSWER -D
The behaviour and processes that govern the textures of magmatic rocks depend
on the content of a magma's three distinct parts: ________.
A) andesite, basalt, and rhyolite
B) quartz, feldspar, and ferromagnesian minerals
C) solid, liquid, and gas
D) high pressure, medium pressure, and low pressure - ANSWER -C
The molten portion of magmas and lavas is made up of ________.
A) complex anion frameworks of oxygen with silicon and aluminum and cation
modifiers made up of different amounts of calcium, sodium, iron, magnesium, and
potassium
B) metamorphic fluids
,C) silicate minerals that have already crystallized
D) solid high pressure forms of water, carbon dioxide, and sulfur dioxide -
ANSWER -A
All of the following are factors that affect the generation of magma except for
________.
A) heat
B) pressure
C) crystal size
D) volatiles - ANSWER -C
The process of ________ is driven by ________ and transforms a magma into an
igneous rock.
A) crystallization, cooling (heat loss)
B) intrusion, overlying rock weight
C) partial melting, pressure increase
D) volcanism, internal heating - ANSWER -A
As melts cool their viscosity increases (they lose their mobility and get stiffer)
even before they start to crystallize because ________.
A) all of the sodium and potassium escape
B) their ions become more disordered
C) the silica tetrahedra in the melt start to link up and make larger and stronger
units
D) they increase in volume - ANSWER -C
The earliest formed crystals (phenocrysts) in a magma tend to be ________.
A) crowded and irregular in shape
B) small and clouded with inclusions of everything that formed later on
C) those that can form only at the lowest temperatures
D) larger and well formed because they have space to grow and a ready supply of
ions - ANSWER -D
The last minerals to crystallize in Bowen's reaction series result in igneous rocks
with a ________composition.
, A) felsic
B) intermediate
C) mafic
D) ultramafic - ANSWER -A
The mechanism of magmatic differentiation involving the removal of denser, early
formed high temperature mineral phases is ________.
A) assimilation
B) crystal settling
C) magma mixing
D) zone refining - ANSWER -B
Which of the following minerals crystallize early in Bowen's reaction series?
A) biotite
B) quartz
C) olivine
D) muscovite - ANSWER -C
Changing the composition of magma by incorporating surrounding host rock is
known as
A) magma mixing
B) partial melting
C) differentiation
D) assimilation - ANSWER -D
The mechanism of selectively removing the minerals which melt at the lowest
temperature is ________.
A) assimilation
B) magmatic differentiation
C) magma mixing
D) partial melting - ANSWER -D
The most abundant elements in common crustal igneous rocks are ________.
A) calcium and sodium
B) iron and magnesium
Answers Verified 100% Correct
All silicate minerals contain which two elements?
A) iron, silicon
B) silicon, sodium
C) oxygen, carbon
D) silicon, oxygen - ANSWER -D
All ferromagnesian minerals contain which two elements?
A) calcium, sodium
B) iron, magnesium
C) iron, potassium
D) chlorine, silicon - ANSWER -B
Which mineral is composed of silicon dioxide (SiO2)?
A) calcite
B) diamond
C) olivine
D) quartz - ANSWER -D
Why doesn't quartz have any cleavages, only fractures?
A) All oxygens are shared between strongly bonded silicons in a 3-D framework.
B) All of the metallic cations form strong webs between the silicate chains.
C) It is made of pure silicon which is very strong.
D) It has strong helical chains in three perpendicular directions. - ANSWER -A
Silicate igneous rocks make up the ________.
A) bulk of volcanic mountains but not much else on Earth
B) bulk of the Earth's crust and mantle
C) densest rocks and are mainly found in the core
,D) majority of shallow rocks covering the continents but everything deeper is
sedimentary and metamorphic - ANSWER -B
Three processes contribute to the formation of every igneous rock: ________.
A) assimilation, crystallization, and dyke injection
B) extrusion, intrusion, and consolidation
C) partial melting, buoyant rise, and crystallization
D) volcanism, plutonism, and magmatic differentiation - ANSWER -C
Plutonic rocks are emplaced at depth yet they can be seen at the Earth's surface
due mainly to
A) catastrophic violent upheavals that bring them to the surface
B) continual ongoing intrusion after the magma solidifies
C) erosion of overlying rocks due to uplift
D) widespread igneous inversion - ANSWER -C
Which of the following is the major dissolved volatile constituent in both magmas
and volcanic gases?
A) carbon monoxide
B) methane
C) nitrous oxide
D) water - ANSWER -D
The behaviour and processes that govern the textures of magmatic rocks depend
on the content of a magma's three distinct parts: ________.
A) andesite, basalt, and rhyolite
B) quartz, feldspar, and ferromagnesian minerals
C) solid, liquid, and gas
D) high pressure, medium pressure, and low pressure - ANSWER -C
The molten portion of magmas and lavas is made up of ________.
A) complex anion frameworks of oxygen with silicon and aluminum and cation
modifiers made up of different amounts of calcium, sodium, iron, magnesium, and
potassium
B) metamorphic fluids
,C) silicate minerals that have already crystallized
D) solid high pressure forms of water, carbon dioxide, and sulfur dioxide -
ANSWER -A
All of the following are factors that affect the generation of magma except for
________.
A) heat
B) pressure
C) crystal size
D) volatiles - ANSWER -C
The process of ________ is driven by ________ and transforms a magma into an
igneous rock.
A) crystallization, cooling (heat loss)
B) intrusion, overlying rock weight
C) partial melting, pressure increase
D) volcanism, internal heating - ANSWER -A
As melts cool their viscosity increases (they lose their mobility and get stiffer)
even before they start to crystallize because ________.
A) all of the sodium and potassium escape
B) their ions become more disordered
C) the silica tetrahedra in the melt start to link up and make larger and stronger
units
D) they increase in volume - ANSWER -C
The earliest formed crystals (phenocrysts) in a magma tend to be ________.
A) crowded and irregular in shape
B) small and clouded with inclusions of everything that formed later on
C) those that can form only at the lowest temperatures
D) larger and well formed because they have space to grow and a ready supply of
ions - ANSWER -D
The last minerals to crystallize in Bowen's reaction series result in igneous rocks
with a ________composition.
, A) felsic
B) intermediate
C) mafic
D) ultramafic - ANSWER -A
The mechanism of magmatic differentiation involving the removal of denser, early
formed high temperature mineral phases is ________.
A) assimilation
B) crystal settling
C) magma mixing
D) zone refining - ANSWER -B
Which of the following minerals crystallize early in Bowen's reaction series?
A) biotite
B) quartz
C) olivine
D) muscovite - ANSWER -C
Changing the composition of magma by incorporating surrounding host rock is
known as
A) magma mixing
B) partial melting
C) differentiation
D) assimilation - ANSWER -D
The mechanism of selectively removing the minerals which melt at the lowest
temperature is ________.
A) assimilation
B) magmatic differentiation
C) magma mixing
D) partial melting - ANSWER -D
The most abundant elements in common crustal igneous rocks are ________.
A) calcium and sodium
B) iron and magnesium
