ASBOG EXAM REVIEW PRACTICE
QUESTIONS WITH COMPLETE
SOLUTION 2025/2026
What does it mean when you have topographic contours on a 1:24,000 scale base map that are roughly
circular and have hachures on the counters? - correct answer ✔They represent a closed depression
You have a base map at a scale of 1:6,000 and you need to represent the information you obtained
during a field investigation of a site that is one square mile, that included mapping of your site as well as
subsurface exploration results. What do you need to do to the map to make it work? - correct answer
✔Use a larger scale map because it covers a smaller area
If you have a map that is at a scale of 1:24,000 and you want to draw a cross section with a 10 times
exaggeration, what will the vertical scale be? - correct answer ✔1" = 200'
What is the approximate exaggerated dip if the vertical scale is exaggerated 10 times and the true dip is
30*? - correct answer ✔80*
What do you do if you have forgotten to research the current magnetic declination before you go to the
field to investigate and map a site for a geologic mapping project? - correct answer ✔Align your map
with two planimetric features and measure the declination with your compasss.
Location and elevation input into your GIS program comes from your GPS system. The maps generated
by this system are based on a reference datum. If the maps were created in 1972, what do you need to
do to use them with the data output from your GPS system? - correct answer ✔Make the conversion
from NAD27 to NAD83.
For a strike and dip of N25*E, 15*N, what is the attitude of the bed in terms of the azimuth? - correct
answer ✔205, 15
,MAP NEEDED PAGE 3: What is the strike and dip of the bed? - correct answer ✔N70*W, 38*NE
MAP NEEDED PAGE 3: What apparent dip would you expect to find along a trench that is perpendicular
to cross section A-A'? - correct answer ✔26*
The top of Unit A is found at location X at the ground surface and is dipping 40* to the west. The slope is
20* to the east. Unit B is 75 feet thick, is conformable with and below Unit A. The slope distance from
the outcrop at the top of Unit A at location X to the outcrop of the top of Unit B is 173 feet. Unit B is a
unit where you would expect a lot of lost circulation when drilling. The top of unit B is found at a depth
of 195 feet. What is the thickness of Unit A? - correct answer ✔150 feet
MAP NEEDED PAGE 4: What geologic law is used to determine the relative ages of the faults? - correct
answer ✔Law of Cross-Cutting relationships
MAP NEEDED PAGE 4: There is a synclinal axis downslope of Unit B. Which direction is the slope facing?
Is it steep?. - correct answer ✔NW and moderately sloping
MAP NEEDED PAGE 4: What is the youngest continuously deposited bed found on the map? - correct
answer ✔Unit D
MAP NEEDED PAGE 4: What type of feature would you expect to see on this map if you had a plunging
anticline? - correct answer ✔Closure of the units with the plunge in the direction of closure
MAP NEEDED PAGE 4: What evidence do you have to determine weather the eastern fault is normal,
reverse or strike-slip? - correct answer ✔Normal east side down because when projected in a cross
section Unit A on the west side is higher than its counterpart on the east side.
MAP NEEDED PAGE 4: If unit A is Permian, what is the most likely age of unit D? - correct answer
✔Cretaceous
, Which of the following survey corrections are required for the given geophysical survey method? -
correct answer ✔Gravity Survey - Bouguer anomaly
When investigating an active fault that is relatively close to the surface to determine the impact if would
have on a planned structure, it is important to locate it precisely and determine the recency of activity.
In order to accomplish this which of the following field methods would be the most appropriate? -
correct answer ✔seismic refraction and trenching
E-LOG ON PG-6: What is the distinguishing feature that would indicate the presence of the fresh water-
salt water interface in this coastal aquifer? - correct answer ✔A change in the resistivity in Unit D with
little corresponding change in the SP log
E-LOG ON PG-6: Where would you install the perforated section in this water supply well? - correct
answer ✔620 to 640
When flying to obtain air photos, the flight lines have to be relatively short before they double back on
themselves. Why is this? - correct answer ✔If the flight lines are too long they become less parallel
with length making it difficult to line up the photographs to make them be able to be viewed in stereo.
Which remote sensing method would be the most appropriate for the monitoring of minor ground
movements in terrain that has many small landslides - correct answer ✔LIDAR (light detection and
ranging)
You are getting ready to undertake an investigation into fault hazards in an urban area. Since this is an
urban area you cannot fly any lower than 1000 feet above the ground surface. The amount of relief
exposed at the site is up to 900 feet of elevation gain. In order to get stereo-paired aerial photographs at
a usable scale for the investigation you need to have a photo scale of 1:2400. Which focal length and
flying height makes the most sense? - correct answer ✔12 inch focal length at a flying height of 2400
feet above the ground
What is the most important reasons why rotary methods are NOT often used in hydrogeological
investigations? - correct answer ✔Because the drilling fluids interfere with the water quality.
QUESTIONS WITH COMPLETE
SOLUTION 2025/2026
What does it mean when you have topographic contours on a 1:24,000 scale base map that are roughly
circular and have hachures on the counters? - correct answer ✔They represent a closed depression
You have a base map at a scale of 1:6,000 and you need to represent the information you obtained
during a field investigation of a site that is one square mile, that included mapping of your site as well as
subsurface exploration results. What do you need to do to the map to make it work? - correct answer
✔Use a larger scale map because it covers a smaller area
If you have a map that is at a scale of 1:24,000 and you want to draw a cross section with a 10 times
exaggeration, what will the vertical scale be? - correct answer ✔1" = 200'
What is the approximate exaggerated dip if the vertical scale is exaggerated 10 times and the true dip is
30*? - correct answer ✔80*
What do you do if you have forgotten to research the current magnetic declination before you go to the
field to investigate and map a site for a geologic mapping project? - correct answer ✔Align your map
with two planimetric features and measure the declination with your compasss.
Location and elevation input into your GIS program comes from your GPS system. The maps generated
by this system are based on a reference datum. If the maps were created in 1972, what do you need to
do to use them with the data output from your GPS system? - correct answer ✔Make the conversion
from NAD27 to NAD83.
For a strike and dip of N25*E, 15*N, what is the attitude of the bed in terms of the azimuth? - correct
answer ✔205, 15
,MAP NEEDED PAGE 3: What is the strike and dip of the bed? - correct answer ✔N70*W, 38*NE
MAP NEEDED PAGE 3: What apparent dip would you expect to find along a trench that is perpendicular
to cross section A-A'? - correct answer ✔26*
The top of Unit A is found at location X at the ground surface and is dipping 40* to the west. The slope is
20* to the east. Unit B is 75 feet thick, is conformable with and below Unit A. The slope distance from
the outcrop at the top of Unit A at location X to the outcrop of the top of Unit B is 173 feet. Unit B is a
unit where you would expect a lot of lost circulation when drilling. The top of unit B is found at a depth
of 195 feet. What is the thickness of Unit A? - correct answer ✔150 feet
MAP NEEDED PAGE 4: What geologic law is used to determine the relative ages of the faults? - correct
answer ✔Law of Cross-Cutting relationships
MAP NEEDED PAGE 4: There is a synclinal axis downslope of Unit B. Which direction is the slope facing?
Is it steep?. - correct answer ✔NW and moderately sloping
MAP NEEDED PAGE 4: What is the youngest continuously deposited bed found on the map? - correct
answer ✔Unit D
MAP NEEDED PAGE 4: What type of feature would you expect to see on this map if you had a plunging
anticline? - correct answer ✔Closure of the units with the plunge in the direction of closure
MAP NEEDED PAGE 4: What evidence do you have to determine weather the eastern fault is normal,
reverse or strike-slip? - correct answer ✔Normal east side down because when projected in a cross
section Unit A on the west side is higher than its counterpart on the east side.
MAP NEEDED PAGE 4: If unit A is Permian, what is the most likely age of unit D? - correct answer
✔Cretaceous
, Which of the following survey corrections are required for the given geophysical survey method? -
correct answer ✔Gravity Survey - Bouguer anomaly
When investigating an active fault that is relatively close to the surface to determine the impact if would
have on a planned structure, it is important to locate it precisely and determine the recency of activity.
In order to accomplish this which of the following field methods would be the most appropriate? -
correct answer ✔seismic refraction and trenching
E-LOG ON PG-6: What is the distinguishing feature that would indicate the presence of the fresh water-
salt water interface in this coastal aquifer? - correct answer ✔A change in the resistivity in Unit D with
little corresponding change in the SP log
E-LOG ON PG-6: Where would you install the perforated section in this water supply well? - correct
answer ✔620 to 640
When flying to obtain air photos, the flight lines have to be relatively short before they double back on
themselves. Why is this? - correct answer ✔If the flight lines are too long they become less parallel
with length making it difficult to line up the photographs to make them be able to be viewed in stereo.
Which remote sensing method would be the most appropriate for the monitoring of minor ground
movements in terrain that has many small landslides - correct answer ✔LIDAR (light detection and
ranging)
You are getting ready to undertake an investigation into fault hazards in an urban area. Since this is an
urban area you cannot fly any lower than 1000 feet above the ground surface. The amount of relief
exposed at the site is up to 900 feet of elevation gain. In order to get stereo-paired aerial photographs at
a usable scale for the investigation you need to have a photo scale of 1:2400. Which focal length and
flying height makes the most sense? - correct answer ✔12 inch focal length at a flying height of 2400
feet above the ground
What is the most important reasons why rotary methods are NOT often used in hydrogeological
investigations? - correct answer ✔Because the drilling fluids interfere with the water quality.
