California Professional Geologist (PG)
Exam With Actual Questions & Verified
Answers, Plus Explained
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Guaranteed Pass 2026/Latest
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1. The Mohs hardness scale is primarily used to:
A. Determine mineral density
B. Identify minerals based on scratch resistance
C. Measure specific gravity
D. Determine cleavage quality
Answer: B
Rationale: Hardness is defined by a mineral’s resistance to scratching,
which is what the Mohs scale measures.
2. A rock formed from the cooling and solidification of magma
beneath the Earth’s surface is:
A. Extrusive igneous
B. Sedimentary
C. Metamorphic
D. Intrusive igneous
Answer: D
,Rationale: Intrusive igneous rocks form from slowly cooled magma
below the surface, producing coarse crystals.
3. Strike refers to:
A. The angle between bedding planes
B. The direction of the line formed by the intersection of a plane with a
horizontal surface
C. The dip direction relative to north
D. The angle of inclination
Answer: B
Rationale: Strike is the compass direction of the line where a geologic
feature intersects a horizontal plane.
4. The San Andreas Fault is classified as a:
A. Normal fault
B. Reverse fault
C. Right-lateral strike-slip fault
D. Thrust fault
Answer: C
Rationale: The San Andreas system is a major right-lateral strike-slip
boundary between the North American and Pacific Plates.
5. A confined aquifer is characterized by:
A. Being above the water table
B. Being overlain by an impermeable layer
C. Having no recharge
D. Only occurring in fractured rock
Answer: B
,Rationale: Confined aquifers are bounded by low-permeability
confining layers.
6. The best indicator of high permeability in an unconsolidated
sediment is:
A. Fine grain size
B. Angular grains
C. Poor sorting
D. Good sorting
Answer: D
Rationale: Well-sorted sediments have interconnected pore spaces
that enhance permeability.
7. Hornfels forms primarily due to:
A. Low-grade regional metamorphism
B. Chemical weathering
C. Contact metamorphism
D. High-pressure subduction
Answer: C
Rationale: Hornfels results from heating of surrounding rocks by
intrusive magma.
8. A geologic map depicting rock units and structures is usually
created at what common scale for site investigations?
A. 1:500,000
B. 1:250,000
C. 1:24,000
D. 1:500
Answer: C
, Rationale: The 1:24,000 scale is standard for detailed USGS
quadrangle maps.
9. The geologic time period in which dinosaurs became extinct:
A. Triassic
B. Permian
C. Cretaceous
D. Jurassic
Answer: C
Rationale: The Cretaceous–Paleogene boundary marks the mass
extinction event.
10. The primary driver of slope instability in California’s coastal ranges
is:
A. High winds
B. Tectonic uplift
C. Weak, clay-rich rocks and high rainfall
D. Solar heating
Answer: C
Rationale: Weathered shales and Franciscan mélange combined with
seasonal rains lead to landslides.
11. Darcy’s law applies to:
A. Turbulent flow only
B. Laminar groundwater flow
C. Surface water velocity
D. Tidal flow
Exam With Actual Questions & Verified
Answers, Plus Explained
Rationales/Expert Verified For
Guaranteed Pass 2026/Latest
Updated/Instant Download Pdf
1. The Mohs hardness scale is primarily used to:
A. Determine mineral density
B. Identify minerals based on scratch resistance
C. Measure specific gravity
D. Determine cleavage quality
Answer: B
Rationale: Hardness is defined by a mineral’s resistance to scratching,
which is what the Mohs scale measures.
2. A rock formed from the cooling and solidification of magma
beneath the Earth’s surface is:
A. Extrusive igneous
B. Sedimentary
C. Metamorphic
D. Intrusive igneous
Answer: D
,Rationale: Intrusive igneous rocks form from slowly cooled magma
below the surface, producing coarse crystals.
3. Strike refers to:
A. The angle between bedding planes
B. The direction of the line formed by the intersection of a plane with a
horizontal surface
C. The dip direction relative to north
D. The angle of inclination
Answer: B
Rationale: Strike is the compass direction of the line where a geologic
feature intersects a horizontal plane.
4. The San Andreas Fault is classified as a:
A. Normal fault
B. Reverse fault
C. Right-lateral strike-slip fault
D. Thrust fault
Answer: C
Rationale: The San Andreas system is a major right-lateral strike-slip
boundary between the North American and Pacific Plates.
5. A confined aquifer is characterized by:
A. Being above the water table
B. Being overlain by an impermeable layer
C. Having no recharge
D. Only occurring in fractured rock
Answer: B
,Rationale: Confined aquifers are bounded by low-permeability
confining layers.
6. The best indicator of high permeability in an unconsolidated
sediment is:
A. Fine grain size
B. Angular grains
C. Poor sorting
D. Good sorting
Answer: D
Rationale: Well-sorted sediments have interconnected pore spaces
that enhance permeability.
7. Hornfels forms primarily due to:
A. Low-grade regional metamorphism
B. Chemical weathering
C. Contact metamorphism
D. High-pressure subduction
Answer: C
Rationale: Hornfels results from heating of surrounding rocks by
intrusive magma.
8. A geologic map depicting rock units and structures is usually
created at what common scale for site investigations?
A. 1:500,000
B. 1:250,000
C. 1:24,000
D. 1:500
Answer: C
, Rationale: The 1:24,000 scale is standard for detailed USGS
quadrangle maps.
9. The geologic time period in which dinosaurs became extinct:
A. Triassic
B. Permian
C. Cretaceous
D. Jurassic
Answer: C
Rationale: The Cretaceous–Paleogene boundary marks the mass
extinction event.
10. The primary driver of slope instability in California’s coastal ranges
is:
A. High winds
B. Tectonic uplift
C. Weak, clay-rich rocks and high rainfall
D. Solar heating
Answer: C
Rationale: Weathered shales and Franciscan mélange combined with
seasonal rains lead to landslides.
11. Darcy’s law applies to:
A. Turbulent flow only
B. Laminar groundwater flow
C. Surface water velocity
D. Tidal flow
