TEXAS PROFESSIONAL GEOSCIENTIST
LICENSING LEVEL I EXAM QUESTIONS WITH
CORRECT ANSWERS (VERIFIED ANSWERS)
PLUS RATIONALES 2026 Q&A | INSTANT
DOWNLOAD
1. Which of the following best defines a mineral?
A. Naturally occurring, solid, definite chemical composition, crystalline
structure
B. Organic substance found in soil
C. Any naturally occurring rock
D. A mixture of solids and liquids
Answer: A
Rationale: Minerals are naturally occurring, inorganic solids with a
definite chemical composition and crystalline structure.
2. The Mohs scale measures:
A. Density of rocks
B. Hardness of minerals
C. Magnetic susceptibility
D. Thermal conductivity
Answer: B
Rationale: The Mohs scale ranks minerals based on their hardness, from
talc (softest) to diamond (hardest).
,3. Which of the following rocks is igneous?
A. Sandstone
B. Basalt
C. Shale
D. Limestone
Answer: B
Rationale: Basalt is formed from cooled and solidified lava, making it an
igneous rock.
4. Metamorphic rocks are formed primarily by:
A. Cooling of magma
B. Compaction of sediments
C. Heat, pressure, and chemical processes
D. Precipitation from water
Answer: C
Rationale: Metamorphic rocks form when preexisting rocks undergo
heat, pressure, and/or chemical changes.
5. Which of the following is a common sedimentary rock?
A. Granite
B. Sandstone
C. Gneiss
D. Basalt
Answer: B
Rationale: Sandstone is a sedimentary rock composed of cemented
sand-sized particles.
,6. The principle of superposition states:
A. Older layers lie above younger layers
B. Younger layers lie above older layers
C. Layers are all the same age
D. Fossils are randomly distributed
Answer: B
Rationale: In undisturbed sedimentary sequences, the youngest layers
are on top and the oldest at the bottom.
7. Which type of fault is caused by compressional stress?
A. Normal fault
B. Reverse fault
C. Strike-slip fault
D. Transform fault
Answer: B
Rationale: Reverse faults occur due to compressional forces that push
rock layers together.
8. The Richter scale measures:
A. Wind speed
B. Earthquake magnitude
C. Soil porosity
D. Rock hardness
Answer: B
Rationale: The Richter scale quantifies the energy released by an
earthquake.
, 9. Which of the following is an aquifer?
A. Impermeable clay layer
B. Saturated, permeable rock layer
C. Igneous intrusion
D. Topsoil
Answer: B
Rationale: An aquifer is a saturated, permeable layer that can transmit
water.
10. Darcy’s Law is used to calculate:
A. Water velocity in rivers
B. Groundwater flow
C. Rock density
D. Soil permeability
Answer: B
Rationale: Darcy’s Law describes the flow of fluid through porous
media, like groundwater through an aquifer.
11. Porosity is defined as:
A. The total volume of voids in a material
B. The rate of water flow
C. Rock hardness
D. Mineral composition
Answer: A
Rationale: Porosity is the fraction of a rock or soil’s volume that is made
up of void spaces.
LICENSING LEVEL I EXAM QUESTIONS WITH
CORRECT ANSWERS (VERIFIED ANSWERS)
PLUS RATIONALES 2026 Q&A | INSTANT
DOWNLOAD
1. Which of the following best defines a mineral?
A. Naturally occurring, solid, definite chemical composition, crystalline
structure
B. Organic substance found in soil
C. Any naturally occurring rock
D. A mixture of solids and liquids
Answer: A
Rationale: Minerals are naturally occurring, inorganic solids with a
definite chemical composition and crystalline structure.
2. The Mohs scale measures:
A. Density of rocks
B. Hardness of minerals
C. Magnetic susceptibility
D. Thermal conductivity
Answer: B
Rationale: The Mohs scale ranks minerals based on their hardness, from
talc (softest) to diamond (hardest).
,3. Which of the following rocks is igneous?
A. Sandstone
B. Basalt
C. Shale
D. Limestone
Answer: B
Rationale: Basalt is formed from cooled and solidified lava, making it an
igneous rock.
4. Metamorphic rocks are formed primarily by:
A. Cooling of magma
B. Compaction of sediments
C. Heat, pressure, and chemical processes
D. Precipitation from water
Answer: C
Rationale: Metamorphic rocks form when preexisting rocks undergo
heat, pressure, and/or chemical changes.
5. Which of the following is a common sedimentary rock?
A. Granite
B. Sandstone
C. Gneiss
D. Basalt
Answer: B
Rationale: Sandstone is a sedimentary rock composed of cemented
sand-sized particles.
,6. The principle of superposition states:
A. Older layers lie above younger layers
B. Younger layers lie above older layers
C. Layers are all the same age
D. Fossils are randomly distributed
Answer: B
Rationale: In undisturbed sedimentary sequences, the youngest layers
are on top and the oldest at the bottom.
7. Which type of fault is caused by compressional stress?
A. Normal fault
B. Reverse fault
C. Strike-slip fault
D. Transform fault
Answer: B
Rationale: Reverse faults occur due to compressional forces that push
rock layers together.
8. The Richter scale measures:
A. Wind speed
B. Earthquake magnitude
C. Soil porosity
D. Rock hardness
Answer: B
Rationale: The Richter scale quantifies the energy released by an
earthquake.
, 9. Which of the following is an aquifer?
A. Impermeable clay layer
B. Saturated, permeable rock layer
C. Igneous intrusion
D. Topsoil
Answer: B
Rationale: An aquifer is a saturated, permeable layer that can transmit
water.
10. Darcy’s Law is used to calculate:
A. Water velocity in rivers
B. Groundwater flow
C. Rock density
D. Soil permeability
Answer: B
Rationale: Darcy’s Law describes the flow of fluid through porous
media, like groundwater through an aquifer.
11. Porosity is defined as:
A. The total volume of voids in a material
B. The rate of water flow
C. Rock hardness
D. Mineral composition
Answer: A
Rationale: Porosity is the fraction of a rock or soil’s volume that is made
up of void spaces.
