AEPA Earth Science Exam

AEPA Earth Science Practice Questions

1. The lithification process results in the formation of which of the following types of rocks?

A: Sedimentary
B: Intrusive igneous
C: Extrusive igneous
D: Metamorphic

2. Which of the following types of igneous rock solidifies deepest beneath the Earth’s surface?

A: Hypabyssal
B: Hypabyssal
C: Volcanic
D: Detrital

3. Physical weathering of rocks can be caused by all of the following EXCEPT:

A: The freezing and thawing of water on the surface of rocks.
B: Changes in temperature.
C: Oxidation.
D: Changes in pressure due to the removal of overlying rocks.

4. Which of the following is NOT an example of chemical weathering of rocks?

A: Highly acidic rainwater causes dissolution of rocks.
B: Minerals that comprise rocks take on water, causing them to enlarge and creating fractures within the rocks.
C: Salt water penetrates fractures in rocks and leaves behind salt crystals that cause fractures.
D: Iron molecules in rocks react with atmospheric oxygen, which causes oxidation.

5. Which of the following lists places several phases of the sedimentary cycle in the correct order?

A: Erosion, weathering, transportation, deposition
B: Weathering, erosion, deposition, transportation
C: Weathering, deposition, erosion, transportation
D: Weathering, erosion, transportation, deposition

6. Which of the following is required for the process of diagenesis (also called lithification)?

A: Magma
B: Water
C: Wind
D: Sulfur

7. Nondetrital sedimentary rock is produced by:

A: Chemical precipitation.
B: Cooling of magma just below the Earth’s surface.
C: Physical weathering processes.
D: Weathering of igneous rock.

8. Leaching in the “A” soil horizon results from:

A: The accumulation of cations in the “B” horizon.
B: The accumulation of cations in the “O” horizon.
C: Contact with acid solutions generated in the “O” horizon.
D: Contact with acid solutions generated in the “B” horizon.

9. . Which of the following statements is true of rocks such as olivine that are found at the top of Bowen’s reaction series?

A: They are classified as metamorphic.
B: They weather more quickly than rocks found lower in the series.
C: They crystallize at lower temperatures than rocks found at the bottom of the series.
D: None of the above

10. Metamorphic rock is produced when which of the following undergoes profound changes as a result of exposure to intense pressure and heat?

A: A batholith
B: A protolith
C: A subduction zone
D: A volcano

Answer key

1. A. The lithification process results in the formation of sedimentary rocks. During lithification, existing rock is compacted and liquid is squeezed from its pores. Eventually, the rock is cemented together, resulting in sedimentary rock.
2. B. Plutonic, or intrusive, rock forms deep beneath the Earth’s surface and cools slowly. Volcanic, or extrusive, rock solidifies at or near the surface. Hypabyssal rock forms below the Earth’s surface, but not at a depth as great as plutonic rock. Detrital rock is a type of sedimentary rock
3. C. Overgrazing and deforestation directly contribute to soil erosion by destroying the natural groundcover that normally prevents soil from being washed and blown away. These activities can ultimately result in desertification, which renders land unsuitable for agriculture.
4. C. When salt water penetrates fractures in rocks and leaves behind salt crystals that cause the rock to fracture, it is considered physical rather than chemical weathering. Chemical weathering involves changes in the molecules that comprise the rocks, while physical weathering occurs when external factors act on the rock without changing its chemical composition in any way.
5. D. Weathering causes erosion, which often leads to transportation and the deposition of eroded material. After the eroded material is deposited in a new location, lithification proceeds and the sedimentary cycle begins anew.
6. B. Water is a key element in the lithification of sedimentary rock. After it is squeezed from the compressed material, it forms a chemical cement that holds the sedimentary rock in place. This cementation process is followed by recrystallization of the rock when equilibrium is reached.
7. A. Non-detrital sedimentary rock is produced by chemical precipitation. In contrast, detrital sedimentary rocks are comprised of pre-existing rocks, such as quartz, or weathered products of pre-existing rocks, such as clay.
8. C. Leaching in the “A” soil horizon results from contact with acid solutions generated in the “O” horizon, which is the uppermost organic layer of soil. Cations that are leached in the “A” soil horizon accumulate in the “B” soil horizon below.
9. B. Rocks such as olivine that are found at the top of Bowen’s reaction series weather more quickly than rocks found lower in the series. This is because rocks high in the series crystallize at higher temperatures than those found lower in the series. This means they are less stable and more susceptible to weathering than rocks that crystallize at lower temperatures, such as quartz.
10. B. Metamorphic rock is produced when a protolith undergoes profound changes after being exposed to extreme heat and pressure. A protolith is any rock that is transformed through this process. The original rock may be sedimentary, igneous, or metamorphic. The extreme heat and pressure that serve as the catalyst for this transformation may be produced by the intrusion of magma or tectonic activity, among other factors.

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