ESS 101 FINAL EXAM 2026/2027
QUESTIONS AND ANSWERS WITH
VERIFIED SOLUTIONS. JUST
RELEASED
1. Which of the following processes is considered the primary driver of plate motion, exerting
the greatest force on subducting lithosphere?
A. Slab pull
B. Ridge push
C. Mantle convection cells
D. Basal drag
Answer: A
Conceptual Explanation: Slab pull, resulting from the sinking of cold, dense oceanic
lithosphere into the mantle, is considered the most significant force driving plate tectonics.
2. In the silicate mineral group, what is the basic building block consisting of one silicon atom
and four oxygen atoms?
A. Silicon-oxygen tetrahedron
B. Silicate octahedron
C. Silicon dioxide crystal
,D. Silicate polymer chain
Answer: A
Conceptual Explanation: The silicon-oxygen tetrahedron is the fundamental unit of all
silicate minerals, organized in various structures like chains, sheets, or frameworks.
3. According to Bowen’s Reaction Series, which mineral is the first to crystallize from a cooling
mafic magma?
A. Olivine
B. Quartz
C. Muscovite
D. Biotite
Answer: A
Conceptual Explanation: Olivine is at the top of the discontinuous series, crystallizing at
the highest temperatures from ultramafic and mafic melts.
4. What type of sedimentary deposit is characterized by a sequence of graded bedding, often
associated with underwater landslides on the continental slope?
A. Evaporites
B. Alluvial fans
C. Varves
D. Turbidites
, Answer: D
Conceptual Explanation: Turbidites are deposits from turbidity currents that show
graded bedding (coarse at the bottom, fine at the top) as the current slows down.
5. Which seismic wave is unable to travel through the Earth’s liquid outer core, providing
evidence for its state?
A. P-waves
B. S-waves
C. Love waves
D. Rayleigh waves
Answer: B
Conceptual Explanation: S-waves (secondary waves) are shear waves and cannot
propagate through fluids, which is why they are blocked by the liquid outer core.
6. The presence of which index mineral in a metamorphic rock typically indicates high-grade
(high temperature and high pressure) metamorphism?
A. Chlorite
B. Sillimanite
C. Muscovite
D. Biotite
Answer: B
QUESTIONS AND ANSWERS WITH
VERIFIED SOLUTIONS. JUST
RELEASED
1. Which of the following processes is considered the primary driver of plate motion, exerting
the greatest force on subducting lithosphere?
A. Slab pull
B. Ridge push
C. Mantle convection cells
D. Basal drag
Answer: A
Conceptual Explanation: Slab pull, resulting from the sinking of cold, dense oceanic
lithosphere into the mantle, is considered the most significant force driving plate tectonics.
2. In the silicate mineral group, what is the basic building block consisting of one silicon atom
and four oxygen atoms?
A. Silicon-oxygen tetrahedron
B. Silicate octahedron
C. Silicon dioxide crystal
,D. Silicate polymer chain
Answer: A
Conceptual Explanation: The silicon-oxygen tetrahedron is the fundamental unit of all
silicate minerals, organized in various structures like chains, sheets, or frameworks.
3. According to Bowen’s Reaction Series, which mineral is the first to crystallize from a cooling
mafic magma?
A. Olivine
B. Quartz
C. Muscovite
D. Biotite
Answer: A
Conceptual Explanation: Olivine is at the top of the discontinuous series, crystallizing at
the highest temperatures from ultramafic and mafic melts.
4. What type of sedimentary deposit is characterized by a sequence of graded bedding, often
associated with underwater landslides on the continental slope?
A. Evaporites
B. Alluvial fans
C. Varves
D. Turbidites
, Answer: D
Conceptual Explanation: Turbidites are deposits from turbidity currents that show
graded bedding (coarse at the bottom, fine at the top) as the current slows down.
5. Which seismic wave is unable to travel through the Earth’s liquid outer core, providing
evidence for its state?
A. P-waves
B. S-waves
C. Love waves
D. Rayleigh waves
Answer: B
Conceptual Explanation: S-waves (secondary waves) are shear waves and cannot
propagate through fluids, which is why they are blocked by the liquid outer core.
6. The presence of which index mineral in a metamorphic rock typically indicates high-grade
(high temperature and high pressure) metamorphism?
A. Chlorite
B. Sillimanite
C. Muscovite
D. Biotite
Answer: B
