ESS 101: Midterm Exam Questions
with Guaranteed Pass Solutions 2025-
2026 Updated.
Match the magma type with the appropriate tectonic setting where it likely forms: Iceland -
Answer basalt
Match the magma type with the appropriate tectonic setting where it likely forms: Sierra
Nevada Batholith - Answer granite
Match the magma type with the appropriate tectonic setting where it likely forms: Phillipine
Islands - Answer andesite
The Columbia Plateau is composed of rock rich in - Answer basalt
The melting temperature of granitic magma (wet melt) - Answer increases as pressure is
reduced (as it rises)
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
How do we know that Earth was created from the debris of a previous star system? - Answer
Dense elements exist that could only have been formed through a Supernova event
Steps of the Nebular Hypothesis - Answer - Supernova and formation of primordial dust cloud
- condensation of primordial dust. Forms disk-shaped nebular cloud rotating counter-clockwise
- Proto sun and planets begin to form
- Accretion of planetesimals and differentiation of planets and moons
- Existing solar system takes shape
,- Planetary orbits are aligned along the sun's equatorial plane (v. random)
- Observations from Hubble and radio astronomy
Characteristics of Terrestrial Planets - Answer - Close to the sun, dense
- Small, rocky (silicate minerals, metallic cores)
Characteristics of Jovian Planets - Answer - Far from the sun, low density
- Large, gaseous (hydrogen, methane)
Can you explain why the earth and terrestrial planets have so little molecular hydrogen
comprising their respective atmospheres; yet the primarodial dust cloud was mostly comprised
of hydrogen gas? - Answer - Key word: heat.
- Jovian planets are located far enough away from the sun that molecular hydrogen is cool and
dense enough to remain in their atmosphere
- Terrestrial planets are close enough to the sun that molecular hydrogen would be too heated,
not dense enough to remain in the atmosphere
What's the inner and outer core of the earth made of? - Answer Iron-Nickel Core
Inner core in which phase? - Answer solid
Outer core in which phase? - Answer liquid
What's the mantle made of? - Answer Fe-Mg Silicate
What's the crust made of? - Answer Fe-Mg-Al Silicate
, - Atmosphere
How is the earth compositionally zoned? - Answer Along a density gradient
How did the earth become compositionally zoned? - Answer - accretion of planetesimals
- initial heating due to kinetic energy of colliding planetesimals and compressional heating
- Additional heating from radioactive decay
- melting point reached, dense iron sinks to core while lighter minerals are displaced outwards
- earth becomes compositionally zoned based on density
- convective overturn in asthenosphere, mantle, and outer core continues today
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
Which heat transfer process is more efficient? - Answer - CONVECTION. Conduction requires
atom-to-atom heat transfer, a very slow process
Why does the earth possess little evidence of its early accretion history? - Answer -
weathering
- vegetation
- spreading of ocean crust-- old crust getting subducted
What earth features were formed from degassing? - Answer - ocean and atmosphere formed
from degassing + condensation
with Guaranteed Pass Solutions 2025-
2026 Updated.
Match the magma type with the appropriate tectonic setting where it likely forms: Iceland -
Answer basalt
Match the magma type with the appropriate tectonic setting where it likely forms: Sierra
Nevada Batholith - Answer granite
Match the magma type with the appropriate tectonic setting where it likely forms: Phillipine
Islands - Answer andesite
The Columbia Plateau is composed of rock rich in - Answer basalt
The melting temperature of granitic magma (wet melt) - Answer increases as pressure is
reduced (as it rises)
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
How do we know that Earth was created from the debris of a previous star system? - Answer
Dense elements exist that could only have been formed through a Supernova event
Steps of the Nebular Hypothesis - Answer - Supernova and formation of primordial dust cloud
- condensation of primordial dust. Forms disk-shaped nebular cloud rotating counter-clockwise
- Proto sun and planets begin to form
- Accretion of planetesimals and differentiation of planets and moons
- Existing solar system takes shape
,- Planetary orbits are aligned along the sun's equatorial plane (v. random)
- Observations from Hubble and radio astronomy
Characteristics of Terrestrial Planets - Answer - Close to the sun, dense
- Small, rocky (silicate minerals, metallic cores)
Characteristics of Jovian Planets - Answer - Far from the sun, low density
- Large, gaseous (hydrogen, methane)
Can you explain why the earth and terrestrial planets have so little molecular hydrogen
comprising their respective atmospheres; yet the primarodial dust cloud was mostly comprised
of hydrogen gas? - Answer - Key word: heat.
- Jovian planets are located far enough away from the sun that molecular hydrogen is cool and
dense enough to remain in their atmosphere
- Terrestrial planets are close enough to the sun that molecular hydrogen would be too heated,
not dense enough to remain in the atmosphere
What's the inner and outer core of the earth made of? - Answer Iron-Nickel Core
Inner core in which phase? - Answer solid
Outer core in which phase? - Answer liquid
What's the mantle made of? - Answer Fe-Mg Silicate
What's the crust made of? - Answer Fe-Mg-Al Silicate
, - Atmosphere
How is the earth compositionally zoned? - Answer Along a density gradient
How did the earth become compositionally zoned? - Answer - accretion of planetesimals
- initial heating due to kinetic energy of colliding planetesimals and compressional heating
- Additional heating from radioactive decay
- melting point reached, dense iron sinks to core while lighter minerals are displaced outwards
- earth becomes compositionally zoned based on density
- convective overturn in asthenosphere, mantle, and outer core continues today
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
Which heat transfer process is more efficient? - Answer - CONVECTION. Conduction requires
atom-to-atom heat transfer, a very slow process
Why does the earth possess little evidence of its early accretion history? - Answer -
weathering
- vegetation
- spreading of ocean crust-- old crust getting subducted
What earth features were formed from degassing? - Answer - ocean and atmosphere formed
from degassing + condensation
