ESS 101: MIDTERM EXAM | QUESTIONS AND ANSWERS
| 2026 UPDATE | WITH COMPLETE SOLUTION
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
Evidence to support the nebular hypothesis Answer - - planets and moons
revolve in a counter-clockwise direction (v. random)
- 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
Differentiated earth order (starting from center) Answer - - Iron-Nickel Core
- Fe-Mg Silicate Mantle
- Fe-Mg-Al Silicate Crust (ocean and continental)
- Oceans
- Atmosphere
How is the earth compositionally zoned? Answer - Along a density gradient
| 2026 UPDATE | WITH COMPLETE SOLUTION
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
Evidence to support the nebular hypothesis Answer - - planets and moons
revolve in a counter-clockwise direction (v. random)
- 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
Differentiated earth order (starting from center) Answer - - Iron-Nickel Core
- Fe-Mg Silicate Mantle
- Fe-Mg-Al Silicate Crust (ocean and continental)
- Oceans
- Atmosphere
How is the earth compositionally zoned? Answer - Along a density gradient
