LSU GEOL 1001 GARELLO EXAM 2
MIDTERM REAL EXAM
QUESTIONS AND ANSWERS TOP
RATED STUDY MATERIAL PASS
LSU GEOL 1001 GARELLO EXAM 2 MIDTERM |
Comprehensive Examination
LSU GEOL 1001 GARELLO EXAM 2 MIDTERM REAL
EXAM QUESTIONS AND ANSWERS TOP RATED STUDY
MATERIAL PASS GUARANTEE LATEST VERSION
INTRODUCTION
This document is an important and very helpful preparation
resource for LSU GEOL 1001 GARELLO EXAM 2 MIDTERM
REAL EXAM QUESTIONS AND ANSWERS TOP RATED
STUDY MATERIAL PASS GUARANTEE LATEST VERSION
2026-2027!!. Every item uses a focused exam stem, four
response options, a keyed response, and a clear rationale,
making it easier to understand the subject, spot distractors, and
build real exam confidence.
Page 1
, Question 1
A basaltic magma undergoes fractional crystallization in a shallow magma
chamber. According to Bowen's Reaction Series, which mineral assemblage
would be the FIRST to crystallize from this melt, and what is the primary
control on the sequence?
A. Quartz and muscovite; controlled by silica saturation
B. Olivine and calcium-rich plagioclase; controlled by decreasing
temperature and melt composition
C. Biotite and orthoclase feldspar; controlled by increasing pressure
D. Amphibole and sodium-rich plagioclase; controlled by volatile content
Correct Answer: B - Olivine and calcium-rich plagioclase;
controlled by decreasing temperature and melt composition
RATIONALE
Bowen's Reaction Series shows that mafic minerals (olivine,
Ca-plagioclase) crystallize first at high temperatures from a basaltic
melt. The sequence is driven by falling temperature and changing melt
composition as early crystals are removed. The other options represent
minerals that crystallize at lower temperatures (felsic) or are not the
first to form from a basaltic magma.
Question 2
At a mid-ocean ridge, symmetric magnetic anomalies are recorded in oceanic
crust. If the half-spreading rate is 2.5 cm/yr and a magnetic reversal is
identified 75 km from the ridge axis, what is the age of that crust?
A. 1.5 million years
B. 3.0 million years
C. 7.5 million years
D. 15.0 million years
Correct Answer: B - 3.0 million years
Page 2
, RATIONALE
Age = distance / half-spreading rate = 75 km / 2.5 cm/yr. Convert 75
km to 7,500,000 cm; 7,500,000 cm ÷ 2.5 cm/yr = 3,000,000 years =
3.0 million years. The other options result from misplacing the
decimal or using full-spreading rate incorrectly.
Question 3
A metamorphic rock contains garnet, staurolite, kyanite, and biotite. Which
metamorphic facies and tectonic setting does this assemblage most likely
indicate?
A. Zeolite facies; shallow burial in a passive margin
B. Amphibolite facies; regional metamorphism in a continental collision
zone
C. Hornblende hornfels facies; contact metamorphism near a pluton
D. Blueschist facies; subduction zone with high pressure and low
temperature
Correct Answer: B - Amphibolite facies; regional metamorphism
in a continental collision zone
RATIONALE
The assemblage garnet + staurolite + kyanite + biotite is characteristic
of medium-grade amphibolite facies metamorphism, typical of
regional metamorphism in continental collision zones. Blueschist
facies would require glaucophane and lawsonite, while hornfels and
zeolite facies lack these index minerals.
Question 4
A geologist observes a fault where the hanging wall has moved down relative
to the footwall, and the fault plane dips 60°. Which type of fault is this, and
what stress regime does it indicate?
A. Reverse fault; compressional stress
Page 3
, B. Normal fault; tensional stress
C. Strike-slip fault; shear stress
D. Thrust fault; compressional stress
Correct Answer: B - Normal fault; tensional stress
RATIONALE
A normal fault is defined by the hanging wall moving down relative to
the footwall, and it typically forms in response to tensional
(extensional) stress. Reverse and thrust faults involve hanging wall
movement up, and strike-slip faults involve horizontal displacement.
Question 5
Which seismic wave type travels through the outer core but is refracted,
creating a shadow zone between 103° and 143° from the epicenter?
A. P-waves
B. S-waves
C. Surface waves
D. Love waves
Correct Answer: A - P-waves
RATIONALE
P-waves travel through solids and liquids but are refracted at the
core-mantle boundary, producing a P-wave shadow zone between
103° and 143°. S-waves cannot pass through the liquid outer core,
creating a larger S-wave shadow zone beyond 103°.
Question 6
A sandstone bed is cut by a dike that is offset by a fault. The fault also cuts an
overlying lava flow. Which principle allows you to determine the relative age
of the fault?
A. Principle of superposition
B. Principle of cross-cutting relationships
Page 4
MIDTERM REAL EXAM
QUESTIONS AND ANSWERS TOP
RATED STUDY MATERIAL PASS
LSU GEOL 1001 GARELLO EXAM 2 MIDTERM |
Comprehensive Examination
LSU GEOL 1001 GARELLO EXAM 2 MIDTERM REAL
EXAM QUESTIONS AND ANSWERS TOP RATED STUDY
MATERIAL PASS GUARANTEE LATEST VERSION
INTRODUCTION
This document is an important and very helpful preparation
resource for LSU GEOL 1001 GARELLO EXAM 2 MIDTERM
REAL EXAM QUESTIONS AND ANSWERS TOP RATED
STUDY MATERIAL PASS GUARANTEE LATEST VERSION
2026-2027!!. Every item uses a focused exam stem, four
response options, a keyed response, and a clear rationale,
making it easier to understand the subject, spot distractors, and
build real exam confidence.
Page 1
, Question 1
A basaltic magma undergoes fractional crystallization in a shallow magma
chamber. According to Bowen's Reaction Series, which mineral assemblage
would be the FIRST to crystallize from this melt, and what is the primary
control on the sequence?
A. Quartz and muscovite; controlled by silica saturation
B. Olivine and calcium-rich plagioclase; controlled by decreasing
temperature and melt composition
C. Biotite and orthoclase feldspar; controlled by increasing pressure
D. Amphibole and sodium-rich plagioclase; controlled by volatile content
Correct Answer: B - Olivine and calcium-rich plagioclase;
controlled by decreasing temperature and melt composition
RATIONALE
Bowen's Reaction Series shows that mafic minerals (olivine,
Ca-plagioclase) crystallize first at high temperatures from a basaltic
melt. The sequence is driven by falling temperature and changing melt
composition as early crystals are removed. The other options represent
minerals that crystallize at lower temperatures (felsic) or are not the
first to form from a basaltic magma.
Question 2
At a mid-ocean ridge, symmetric magnetic anomalies are recorded in oceanic
crust. If the half-spreading rate is 2.5 cm/yr and a magnetic reversal is
identified 75 km from the ridge axis, what is the age of that crust?
A. 1.5 million years
B. 3.0 million years
C. 7.5 million years
D. 15.0 million years
Correct Answer: B - 3.0 million years
Page 2
, RATIONALE
Age = distance / half-spreading rate = 75 km / 2.5 cm/yr. Convert 75
km to 7,500,000 cm; 7,500,000 cm ÷ 2.5 cm/yr = 3,000,000 years =
3.0 million years. The other options result from misplacing the
decimal or using full-spreading rate incorrectly.
Question 3
A metamorphic rock contains garnet, staurolite, kyanite, and biotite. Which
metamorphic facies and tectonic setting does this assemblage most likely
indicate?
A. Zeolite facies; shallow burial in a passive margin
B. Amphibolite facies; regional metamorphism in a continental collision
zone
C. Hornblende hornfels facies; contact metamorphism near a pluton
D. Blueschist facies; subduction zone with high pressure and low
temperature
Correct Answer: B - Amphibolite facies; regional metamorphism
in a continental collision zone
RATIONALE
The assemblage garnet + staurolite + kyanite + biotite is characteristic
of medium-grade amphibolite facies metamorphism, typical of
regional metamorphism in continental collision zones. Blueschist
facies would require glaucophane and lawsonite, while hornfels and
zeolite facies lack these index minerals.
Question 4
A geologist observes a fault where the hanging wall has moved down relative
to the footwall, and the fault plane dips 60°. Which type of fault is this, and
what stress regime does it indicate?
A. Reverse fault; compressional stress
Page 3
, B. Normal fault; tensional stress
C. Strike-slip fault; shear stress
D. Thrust fault; compressional stress
Correct Answer: B - Normal fault; tensional stress
RATIONALE
A normal fault is defined by the hanging wall moving down relative to
the footwall, and it typically forms in response to tensional
(extensional) stress. Reverse and thrust faults involve hanging wall
movement up, and strike-slip faults involve horizontal displacement.
Question 5
Which seismic wave type travels through the outer core but is refracted,
creating a shadow zone between 103° and 143° from the epicenter?
A. P-waves
B. S-waves
C. Surface waves
D. Love waves
Correct Answer: A - P-waves
RATIONALE
P-waves travel through solids and liquids but are refracted at the
core-mantle boundary, producing a P-wave shadow zone between
103° and 143°. S-waves cannot pass through the liquid outer core,
creating a larger S-wave shadow zone beyond 103°.
Question 6
A sandstone bed is cut by a dike that is offset by a fault. The fault also cuts an
overlying lava flow. Which principle allows you to determine the relative age
of the fault?
A. Principle of superposition
B. Principle of cross-cutting relationships
Page 4
