1
ESS 101: Midterm Practice Exam | Verified
Questions, Correct Answers & Complete
Solutions | A+ Graded | New 2025 Version
1. Why did the earth heat up and then rapidly cool during the differentiation process? -
ANSWER - Conduction: SLOW, rate of heat leaving too slow to cool the rapidly heating
planet, therefore liquification
- Convection: FAST, liquid--> solid, rapid cooling
2. Which heat transfer process is more efficient? - ANSWER - CONVECTION. Conduction
requires atom-to-atom heat transfer, a very slow process
3. Match the magma/lava type with the appropriate geographic/tectonic setting where it
likely formed.
Columbia Plateau
Asthenosphere
Mount Fuji, Japan - ANSWER 3) basalt
4) periodite
5) andesite
4. Match the magma type with the appropriate tectonic setting where it likely forms.
Iceland
Sierra Nevada Batholith
Philippine Islands
Ural mountains
(basalt, granite, andesite, periotite, andalucite)r - ANSWER Iceland = Basalt
Sierra Nevada Batholith = Granite
Philippine Islands = Andesite
Ural mountains= granite
5. The Columbia Plateau is composed of rock rich in: - ANSWER Basalt
6. The melting temperature of granitic magma (wet melt) ______________: - ANSWER
increases as pressure is reduced (as it rises). Therefore it solidifies as it rises and rarely
gets to surface. Dry basaltic magma has opposite effect.
7. A partial melt of the asthenosphere will not rise toward the surface because
_____________. - ANSWER the above question is incorrect because an asthenospheric
melt will rise towards the surface
, 2
8. Aa basalts _______. - ANSWER are blocky textured flows that form as the viscosity
increases during degassing
9. When two ocean plates converge ___________. - ANSWER the older plate will be
subducted (because it is more dense)
10. The most widely accepted explanation for the earth's magnetic field is
_______________. - ANSWER movement of electrons in the molten iron of its outer
core
11. What kind of plate margin exists today in East Africa? - ANSWER Divergent Margins
12. What type of volcanic rock would incorporate lithic fragments during the eruption. -
ANSWER Volcanic Tuff
13. Why does potassium feldspar develop cleavage planes yet it is a framework silicate
mineral with all its oxygen atoms shared between tetrahedra? - ANSWER this mineral
has an aluminum atom in some of its tetrahedra which requires additional ionic bonds
with
potassium atoms
14. 3. ______________ flows from Mount Vesuvius obliterated the Roman city of Pompeii
in 79AD. - ANSWER Pyroclastic
15. What is Lahar? - ANSWER Mudflow on the slopes of a volcano
16. Magnetic minerals that crystallize in a lava flow erupted near the North Pole today will
________. - ANSWER be oriented perpendicular to the surface of the lava flow
17. Rank the chemical bonds forming minerals from weakest to strongest (Van der waals,
covalent, ionic) - ANSWER Van der Waals, ionic, covalent
18. What are the two most common elements comprising rocks of the crust and mantle. -
ANSWER Si and O
19. How does the silicate tetrahedron achieve charge balance? - ANSWER it will share
electrons between oxygen atoms AND it will form ionic bonds with available cations. -4
net charge
20. Why do the large Jovian planets have molecular hydrogen in their atmospheres, but the
smaller terrestrial planets do not? - ANSWER The Jovian planets are further from the sun
and the hydrogen gas can condense and be held by gravity
21. Most mined iron ore occurs in the ____________ mineral group. - ANSWER oxide (Fe-
Oxide)
, 3
22. Define "ore" - ANSWER Metallic ores are oxides, silicates, and sulfides... "Native"
metals
23. Most metallic ore bodies, such as lead, silver and copper occur in the __________
mineral group. - ANSWER sulfide
24. What is the significance of (OH) in the amphibole crystal structure? - ANSWER it is
water likely incorporated during the subduction process
25. Arrange the compositional zones of the earth according to their respective density
(lightest to densest) - ANSWER Continental crust, ocean crust, mantle, outer core, inner
core
26. What kind of tectonic setting is represented by Yellowstone Park? - ANSWER hotspotco
27. Meteorites that strike the earth are predominantly composed of ____________? -
ANSWER iron-nickel and silicate minerals
28. Why do seismic waves decelerate in the "low velocity zone?" - ANSWER "the low
velocity zone" is at the partial melting temperature for the earth's mantle
29. During differentiation of the earth into its compositional zones heat was generated from
_________. - ANSWER kinetic energy of impacting planetesimals
AND compressional heating during condensation
AND radioactive heating
30. Nevada and Utah? - ANSWER a spreading ridge was subducted under California and is
now upwelling beneath the Basin and Range
31. Transform plate boundaries are typically associated with ___________. - ANSWER
divergent margins where the rate of spreading is different along segments of the
spreading ridge
32. The cause of volcanism observed in the Cascades is similar to that of ________. -
ANSWER the Phillipines
33. A shield volcano has a lower slope angle than a strato (composite) volcano because
________. - ANSWER its basaltic lava flows have lower viscosities than the andesitic
flows of strato volcanoes
34. What is the significance of the change in direction of the Hawaiian Island and the
Emperor Seamount chains? - ANSWER the tectonic plate on which both island chains sit
changed directions
35. Which tectonic margin would tend to have only shallow focused earthquakes? -
ANSWER Divergent and Transform
ESS 101: Midterm Practice Exam | Verified
Questions, Correct Answers & Complete
Solutions | A+ Graded | New 2025 Version
1. Why did the earth heat up and then rapidly cool during the differentiation process? -
ANSWER - Conduction: SLOW, rate of heat leaving too slow to cool the rapidly heating
planet, therefore liquification
- Convection: FAST, liquid--> solid, rapid cooling
2. Which heat transfer process is more efficient? - ANSWER - CONVECTION. Conduction
requires atom-to-atom heat transfer, a very slow process
3. Match the magma/lava type with the appropriate geographic/tectonic setting where it
likely formed.
Columbia Plateau
Asthenosphere
Mount Fuji, Japan - ANSWER 3) basalt
4) periodite
5) andesite
4. Match the magma type with the appropriate tectonic setting where it likely forms.
Iceland
Sierra Nevada Batholith
Philippine Islands
Ural mountains
(basalt, granite, andesite, periotite, andalucite)r - ANSWER Iceland = Basalt
Sierra Nevada Batholith = Granite
Philippine Islands = Andesite
Ural mountains= granite
5. The Columbia Plateau is composed of rock rich in: - ANSWER Basalt
6. The melting temperature of granitic magma (wet melt) ______________: - ANSWER
increases as pressure is reduced (as it rises). Therefore it solidifies as it rises and rarely
gets to surface. Dry basaltic magma has opposite effect.
7. A partial melt of the asthenosphere will not rise toward the surface because
_____________. - ANSWER the above question is incorrect because an asthenospheric
melt will rise towards the surface
, 2
8. Aa basalts _______. - ANSWER are blocky textured flows that form as the viscosity
increases during degassing
9. When two ocean plates converge ___________. - ANSWER the older plate will be
subducted (because it is more dense)
10. The most widely accepted explanation for the earth's magnetic field is
_______________. - ANSWER movement of electrons in the molten iron of its outer
core
11. What kind of plate margin exists today in East Africa? - ANSWER Divergent Margins
12. What type of volcanic rock would incorporate lithic fragments during the eruption. -
ANSWER Volcanic Tuff
13. Why does potassium feldspar develop cleavage planes yet it is a framework silicate
mineral with all its oxygen atoms shared between tetrahedra? - ANSWER this mineral
has an aluminum atom in some of its tetrahedra which requires additional ionic bonds
with
potassium atoms
14. 3. ______________ flows from Mount Vesuvius obliterated the Roman city of Pompeii
in 79AD. - ANSWER Pyroclastic
15. What is Lahar? - ANSWER Mudflow on the slopes of a volcano
16. Magnetic minerals that crystallize in a lava flow erupted near the North Pole today will
________. - ANSWER be oriented perpendicular to the surface of the lava flow
17. Rank the chemical bonds forming minerals from weakest to strongest (Van der waals,
covalent, ionic) - ANSWER Van der Waals, ionic, covalent
18. What are the two most common elements comprising rocks of the crust and mantle. -
ANSWER Si and O
19. How does the silicate tetrahedron achieve charge balance? - ANSWER it will share
electrons between oxygen atoms AND it will form ionic bonds with available cations. -4
net charge
20. Why do the large Jovian planets have molecular hydrogen in their atmospheres, but the
smaller terrestrial planets do not? - ANSWER The Jovian planets are further from the sun
and the hydrogen gas can condense and be held by gravity
21. Most mined iron ore occurs in the ____________ mineral group. - ANSWER oxide (Fe-
Oxide)
, 3
22. Define "ore" - ANSWER Metallic ores are oxides, silicates, and sulfides... "Native"
metals
23. Most metallic ore bodies, such as lead, silver and copper occur in the __________
mineral group. - ANSWER sulfide
24. What is the significance of (OH) in the amphibole crystal structure? - ANSWER it is
water likely incorporated during the subduction process
25. Arrange the compositional zones of the earth according to their respective density
(lightest to densest) - ANSWER Continental crust, ocean crust, mantle, outer core, inner
core
26. What kind of tectonic setting is represented by Yellowstone Park? - ANSWER hotspotco
27. Meteorites that strike the earth are predominantly composed of ____________? -
ANSWER iron-nickel and silicate minerals
28. Why do seismic waves decelerate in the "low velocity zone?" - ANSWER "the low
velocity zone" is at the partial melting temperature for the earth's mantle
29. During differentiation of the earth into its compositional zones heat was generated from
_________. - ANSWER kinetic energy of impacting planetesimals
AND compressional heating during condensation
AND radioactive heating
30. Nevada and Utah? - ANSWER a spreading ridge was subducted under California and is
now upwelling beneath the Basin and Range
31. Transform plate boundaries are typically associated with ___________. - ANSWER
divergent margins where the rate of spreading is different along segments of the
spreading ridge
32. The cause of volcanism observed in the Cascades is similar to that of ________. -
ANSWER the Phillipines
33. A shield volcano has a lower slope angle than a strato (composite) volcano because
________. - ANSWER its basaltic lava flows have lower viscosities than the andesitic
flows of strato volcanoes
34. What is the significance of the change in direction of the Hawaiian Island and the
Emperor Seamount chains? - ANSWER the tectonic plate on which both island chains sit
changed directions
35. Which tectonic margin would tend to have only shallow focused earthquakes? -
ANSWER Divergent and Transform
