California Professional Geologist (PG) Actual Exam
(Latest Update ) Questions & Answers with
Rationales| 100% Correct | Grade.
1. The primary purpose of a geologic site investigation is to:
A) Determine property value
B) Identify geologic hazards and subsurface conditions ✅
C) Measure surface vegetation
D) Conduct archeological surveys
Answer: B
Rationale: Professional Geologists must evaluate soil, rock, and hazard
conditions to guide safe development.
2. An active fault in California is defined as one that:
A) Has moved within the last 1,000 years
B) Has moved within the last 11,000 years ✅
C) Is visible on the surface
D) Is underwater only
Answer: B
Rationale: Active faults are Holocene-aged and may produce future
earthquakes.
3. Liquefaction is most likely in soils that are:
A) Dense clay
B) Loose, saturated sand ✅
C) Bedrock
D) Gravel
Answer: B
Rationale: Saturated, loose sands lose strength under seismic shaking.
4. The angle of repose of unconsolidated granular material refers to:
A) The slope where material remains stable ✅
B) Fault dip angle
C) Bedding strike
, D) Water table gradient
Answer: A
Rationale: It represents the steepest stable slope for granular materials.
5. Standard Penetration Test (SPT) is used to determine:
A) Groundwater depth
B) Soil shear strength and density ✅
C) Surface slope angle
D) Rock hardness only
Answer: B
Rationale: SPT provides resistance data used for engineering design.
6. A translational landslide moves:
A) Rotationally
B) Along a planar surface ✅
C) Free-fall
D) As a debris flow
Answer: B
Rationale: Translational slides slide along a planar failure surface.
7. Which geologic process most commonly causes coastal cliff retreat in
California?
A) Volcanism
B) Wave erosion ✅
C) Tectonic uplift
D) Wind deposition
Answer: B
Rationale: Wave action undermines cliffs, leading to collapse.
8. Blind faults are:
A) Visible at the surface
B) Not expressed at the surface ✅
C) Non-seismic
D) Found only offshore
Answer: B
Rationale: Blind faults can generate earthquakes without surface rupture.
, 9. Expansive clay soils can:
A) Cause foundation heave or cracking ✅
B) Reduce earthquake risk
C) Improve drainage
D) Prevent landslides
Answer: A
Rationale: They swell when wet and shrink when dry, damaging structures.
10. Geologic maps show:
A) Vegetation only
B) Rock types, faults, and structures ✅
C) Property boundaries
D) Road networks
Answer: B
Rationale: They depict lithology, structures, and hazard features.
11. The California Geological Survey (CGS) designates:
A) Seismic Hazard Zones ✅
B) Building permits
C) Flood zones only
D) Water rights
Answer: A
Rationale: CGS maps areas susceptible to earthquakes, landslides, and
liquefaction.
12. Groundwater flow direction is generally perpendicular to:
A) Contour lines ✅
B) Slope face
C) Fault line
D) Rock bedding
Answer: A
Rationale: Groundwater flows from high to low hydraulic head,
perpendicular to equipotential lines.
13. Which slope failure is characterized by rotational movement along a curved
surface?
(Latest Update ) Questions & Answers with
Rationales| 100% Correct | Grade.
1. The primary purpose of a geologic site investigation is to:
A) Determine property value
B) Identify geologic hazards and subsurface conditions ✅
C) Measure surface vegetation
D) Conduct archeological surveys
Answer: B
Rationale: Professional Geologists must evaluate soil, rock, and hazard
conditions to guide safe development.
2. An active fault in California is defined as one that:
A) Has moved within the last 1,000 years
B) Has moved within the last 11,000 years ✅
C) Is visible on the surface
D) Is underwater only
Answer: B
Rationale: Active faults are Holocene-aged and may produce future
earthquakes.
3. Liquefaction is most likely in soils that are:
A) Dense clay
B) Loose, saturated sand ✅
C) Bedrock
D) Gravel
Answer: B
Rationale: Saturated, loose sands lose strength under seismic shaking.
4. The angle of repose of unconsolidated granular material refers to:
A) The slope where material remains stable ✅
B) Fault dip angle
C) Bedding strike
, D) Water table gradient
Answer: A
Rationale: It represents the steepest stable slope for granular materials.
5. Standard Penetration Test (SPT) is used to determine:
A) Groundwater depth
B) Soil shear strength and density ✅
C) Surface slope angle
D) Rock hardness only
Answer: B
Rationale: SPT provides resistance data used for engineering design.
6. A translational landslide moves:
A) Rotationally
B) Along a planar surface ✅
C) Free-fall
D) As a debris flow
Answer: B
Rationale: Translational slides slide along a planar failure surface.
7. Which geologic process most commonly causes coastal cliff retreat in
California?
A) Volcanism
B) Wave erosion ✅
C) Tectonic uplift
D) Wind deposition
Answer: B
Rationale: Wave action undermines cliffs, leading to collapse.
8. Blind faults are:
A) Visible at the surface
B) Not expressed at the surface ✅
C) Non-seismic
D) Found only offshore
Answer: B
Rationale: Blind faults can generate earthquakes without surface rupture.
, 9. Expansive clay soils can:
A) Cause foundation heave or cracking ✅
B) Reduce earthquake risk
C) Improve drainage
D) Prevent landslides
Answer: A
Rationale: They swell when wet and shrink when dry, damaging structures.
10. Geologic maps show:
A) Vegetation only
B) Rock types, faults, and structures ✅
C) Property boundaries
D) Road networks
Answer: B
Rationale: They depict lithology, structures, and hazard features.
11. The California Geological Survey (CGS) designates:
A) Seismic Hazard Zones ✅
B) Building permits
C) Flood zones only
D) Water rights
Answer: A
Rationale: CGS maps areas susceptible to earthquakes, landslides, and
liquefaction.
12. Groundwater flow direction is generally perpendicular to:
A) Contour lines ✅
B) Slope face
C) Fault line
D) Rock bedding
Answer: A
Rationale: Groundwater flows from high to low hydraulic head,
perpendicular to equipotential lines.
13. Which slope failure is characterized by rotational movement along a curved
surface?
