PROFESSIONAL GEOLOGIST (PG) CERTIFICATION
EXAMINATION
PRACTICE OF GEOLOGY (PG) EXAMINATION –
ASBOG
2026–2027 TESTING CYCLE
SECTION 1: GENERAL AND FIELD GEOLOGY (Questions 1–20)
Question 1: A geologist is planning a subsurface investigation to characterize a site for a
proposed dam foundation. Which of the following is the MOST appropriate first step in the
investigation?
Answer: Compile and review existing geologic maps, aerial photographs, and previous
subsurface data for the site.
Rationale: The initial phase of any geological investigation should involve compiling and
organizing available information to plan the investigation. This includes reviewing existing
maps, reports, and data before any new field or laboratory work begins. This approach is
consistent with ASBOG Domain A requirements for planning geological investigations.
Question 2: When collecting field data using a handheld GPS unit, which of the following
factors has the GREATEST effect on positional accuracy?
,Answer: Satellite geometry and the number of satellites in view (Dilution of Precision – DOP).
Rationale: Dilution of Precision (DOP) is a measure of satellite geometry quality. Poor satellite
geometry (high DOP) significantly degrades positional accuracy, often more than atmospheric
effects or multipath in modern receivers. ASBOG Domain A requires competency in GPS and
GIS applications.
Question 3: A geologist is preparing a geologic cross-section from surface mapping and
borehole data. The MOST appropriate way to project data onto the section line is:
Answer: Project data perpendicular to strike for structures and along strike for stratigraphic
contacts, depending on the data type.
Rationale: Structural data (e.g., fault planes, fold axes) should generally be projected
perpendicular to strike to maintain true structural relationships. Stratigraphic contacts should
be projected along strike to maintain stratigraphic continuity. Proper projection techniques are
critical for accurate geologic section construction, a key skill in Domain A.
Question 4: A geologist observes that a rock unit on one side of a fault has been repeated on the
other side. This observation is MOST indicative of:
Answer: A thrust fault.
,Rationale: Thrust faults are low-angle reverse faults that can repeat stratigraphic sections,
bringing older rocks over younger rocks. This repetition of strata is a classic indicator of thrust
faulting. Normal faults typically omit section, and strike-slip faults cause lateral offset without
significant repetition or omission.
Question 5: Which of the following geophysical methods is BEST suited for detecting near-
surface voids and cavities?
Answer: Ground-penetrating radar (GPR).
Rationale: GPR is highly effective for detecting shallow subsurface voids, cavities, and buried
utilities due to its high resolution in the near-surface environment. It uses electromagnetic waves
to image subsurface features. While resistivity and seismic methods can also detect voids, GPR is
typically the method of choice for shallow, high-resolution void detection.
Question 6: During a field investigation, a geologist collects rock samples for laboratory
analysis. Which of the following is the MOST important consideration for ensuring sample
integrity?
Answer: Proper sample labeling, chain-of-custody documentation, and appropriate storage
conditions.
, Rationale: Sample integrity depends on proper labeling, documentation (chain of custody), and
storage to prevent contamination or alteration. Without these, even the most carefully collected
samples may yield unreliable results. This aligns with ASBOG Domain A requirements for
documentation and record keeping.
Question 7: A geologist is using a plane table and alidade for field mapping. This method is
MOST useful for:
Answer: Creating detailed topographic and geologic maps in areas without modern surveying
equipment.
Rationale: The plane table and alidade is a traditional field mapping technique that allows
direct, in-field creation of maps. It remains useful in remote areas where GPS or total stations
are impractical, or for detailed mapping where the geologist needs to see and adjust the map in
real-time.
Question 8: When interpreting aerial photographs for geologic mapping, which of the following
features is MOST indicative of a fault?
Answer: Linear topographic lineaments, offset drainage patterns, and truncated geologic
contacts.
EXAMINATION
PRACTICE OF GEOLOGY (PG) EXAMINATION –
ASBOG
2026–2027 TESTING CYCLE
SECTION 1: GENERAL AND FIELD GEOLOGY (Questions 1–20)
Question 1: A geologist is planning a subsurface investigation to characterize a site for a
proposed dam foundation. Which of the following is the MOST appropriate first step in the
investigation?
Answer: Compile and review existing geologic maps, aerial photographs, and previous
subsurface data for the site.
Rationale: The initial phase of any geological investigation should involve compiling and
organizing available information to plan the investigation. This includes reviewing existing
maps, reports, and data before any new field or laboratory work begins. This approach is
consistent with ASBOG Domain A requirements for planning geological investigations.
Question 2: When collecting field data using a handheld GPS unit, which of the following
factors has the GREATEST effect on positional accuracy?
,Answer: Satellite geometry and the number of satellites in view (Dilution of Precision – DOP).
Rationale: Dilution of Precision (DOP) is a measure of satellite geometry quality. Poor satellite
geometry (high DOP) significantly degrades positional accuracy, often more than atmospheric
effects or multipath in modern receivers. ASBOG Domain A requires competency in GPS and
GIS applications.
Question 3: A geologist is preparing a geologic cross-section from surface mapping and
borehole data. The MOST appropriate way to project data onto the section line is:
Answer: Project data perpendicular to strike for structures and along strike for stratigraphic
contacts, depending on the data type.
Rationale: Structural data (e.g., fault planes, fold axes) should generally be projected
perpendicular to strike to maintain true structural relationships. Stratigraphic contacts should
be projected along strike to maintain stratigraphic continuity. Proper projection techniques are
critical for accurate geologic section construction, a key skill in Domain A.
Question 4: A geologist observes that a rock unit on one side of a fault has been repeated on the
other side. This observation is MOST indicative of:
Answer: A thrust fault.
,Rationale: Thrust faults are low-angle reverse faults that can repeat stratigraphic sections,
bringing older rocks over younger rocks. This repetition of strata is a classic indicator of thrust
faulting. Normal faults typically omit section, and strike-slip faults cause lateral offset without
significant repetition or omission.
Question 5: Which of the following geophysical methods is BEST suited for detecting near-
surface voids and cavities?
Answer: Ground-penetrating radar (GPR).
Rationale: GPR is highly effective for detecting shallow subsurface voids, cavities, and buried
utilities due to its high resolution in the near-surface environment. It uses electromagnetic waves
to image subsurface features. While resistivity and seismic methods can also detect voids, GPR is
typically the method of choice for shallow, high-resolution void detection.
Question 6: During a field investigation, a geologist collects rock samples for laboratory
analysis. Which of the following is the MOST important consideration for ensuring sample
integrity?
Answer: Proper sample labeling, chain-of-custody documentation, and appropriate storage
conditions.
, Rationale: Sample integrity depends on proper labeling, documentation (chain of custody), and
storage to prevent contamination or alteration. Without these, even the most carefully collected
samples may yield unreliable results. This aligns with ASBOG Domain A requirements for
documentation and record keeping.
Question 7: A geologist is using a plane table and alidade for field mapping. This method is
MOST useful for:
Answer: Creating detailed topographic and geologic maps in areas without modern surveying
equipment.
Rationale: The plane table and alidade is a traditional field mapping technique that allows
direct, in-field creation of maps. It remains useful in remote areas where GPS or total stations
are impractical, or for detailed mapping where the geologist needs to see and adjust the map in
real-time.
Question 8: When interpreting aerial photographs for geologic mapping, which of the following
features is MOST indicative of a fault?
Answer: Linear topographic lineaments, offset drainage patterns, and truncated geologic
contacts.
