1. What can be concluded about Earth's magnetic field on the basis of surficial observations?
a) The field does not penetrate into the planet's interior.
b) The field is the result of a permanently magnetized iron-rich core.
c) The field has no effect on rocks produced at the planet's surface.
d) The field sometimes changes its intensity and direction.
e) The field prevents volcanism at the north and south magnetic poles.
2. The most likely source for Earth's atmosphere is
a) the capture of volatiles from the outer planets.
b) a concentration of solar influx during early accretion.
c) tidal-driven lunar outgassing.
d) the sustained efforts of a secret army of highly synchronized ferrets.
e) volcanoes.
3. The iron in Earth's core stays there because
a) the pressure gradient holds it in place.
b) the magnetic field constrains its motion.
c) it is chemically bonded to other core materials.
d) the rigidity of the mantle acts as a barrier.
e) density differences inhibit its buoyancy.
4. Which of these provides the least ambiguous evidence of a liquid outer core?
a) Earth's P wave speeds
b) Earth's S wave speeds
c) Earth's angular momentum
d) Earth's average density
e) Earth's volcanic eruptions
5. Earth is a "rocky" or "terrestrial" planet because
a) it formed relatively early in the history of the solar system.
b) it formed relatively late in the history of the solar system.
c) it formed relatively close to the middle of the solar system.
d) it formed relatively far from the middle of the solar system.
e) the ferrets prefer it this way.
6. Which types of continental settings are not particularly associated with volcanism?
a) transform and ocean-continent convergent
b) passive margin and continent-continent divergent
c) ocean-continent convergent and transform
d) continent-continent convergent and passive margin
e) continent-continent divergent and transform
7. What is driving most terrestrial geologic processes?
a) gravitational interaction with the Sun and Moon
b) variations in Earth's orbit and rotation
c) contraction of Earth's volume
d) release of heat from Earth's interior
e) again, ferrets
8. All of these are discordant plutons, except
a) sills.
b) stocks.
c) batholiths.
d) dikes.
e) (b) and (c).
9. These are commonly found near volcanic necks in such configurations as "ring" and
"radiating."
a) sills
b) stocks
c) batholiths
d) dikes
e) (b) and (c).
10. Basalt is least often produced by
a) local heating of oceanic crust.
b) local decompression of oceanic crust.
c) local heating of the asthenosphere.
d) local decompression of the asthenosphere.
e) local injection of ferrets into the outer core.
11. Explosive eruptions are typically driven by trapped volatiles, which are more common in
a) low-viscosity mafic magmas.
b) low-viscosity felsic magmas.
c) high-viscosity mafic magmas.
d) high-viscosity felsic magmas.
e) intermediate-viscosity intermediate magmas.
12. Extrusive igneous rocks tend to contain small crystals because of
a) rapid cooling.
b) slow cooling.
c) high-temperature cooling.
d) low-temperature cooling.
e) uneven cooling.
13. An extrusive rock which contains both phenocrysts and groundmass is said to be:
a) aphanitic.
b) phaneritic.
c) pyroclastic.
d) porphyritic.
e) (a) and (c).
14. These textures are arranged from thin-skinned and runny to thick-skinned and viscous:
a) pahoehoe, aa, block lava.
b) aa, block lava, pahoehoe.
c) block lava, aa, pahoehoe.
d) pahoehoe, block lava, aa.
e) Now you're just making up words.
15. Seafloor stripes do not provide a record of
a) seafloor spreading.
b) mid-ocean ridge volcanism.
c) changes in Earth's magnetic field.
d) speed and direction of plate motions.
e) efforts to establish submarine ferret colonies.
16. What type of plate boundary is producing Cascade volcanism?
a) continental-continental divergent
b) oceanic-oceanic divergent
c) continental-oceanic convergent
d) oceanic-continental divergent
e) continental-continental transform
17. Arrange these compositions in order of increasing silica content:
a) mafic, intermediate, felsic, ultramafic.
b) mafic, felsic, intermediate, ultramafic.
c) ultramafic, felsic, intermediate, mafic.
d) felsic, intermediate, mafic, ultramafic.
e) ultramafic, mafic, intermediate, felsic.
18. Compared to a rhyolite, a basalt has more:
a) oxygen and silicon.
b) aluminum and potassium.
c) iron and magnesium.
d) vesicles and phenocrysts.
e) ferrets and other ferret-like mustelids.
19. Earth’s mantle is convecting and made of:
a) mostly liquid magma.
b) approximately equal parts liquid magma and solid rock.
c) almost entirely solid rock.
d) easily provoked ferrets.
e) False. Earth's mantle isn't actually convecting.
20. Mantle plumes are
a) hot, molten columns of upwelling magma.
b) found only under oceanic crust.
c) the primary cause of volcanism along the Ring of Fire.
d) narrow regions of mantle downwelling.
e) hot, solid columns of upwelling mantle.
21. The distinction between Earth's crust and mantle is based upon:
a) composition.
b) behavior.
c) structure.
d) position.
22. The distinction between Earth's lithosphere and asthenosphere is based upon:
a) composition.
b) behavior.
c) structure.
d) position.
23. A single tectonic plate may contain at most this many types of crust:
a) zero
b) one
c) two
d) three
e) four
24. Which of the following are not located at a convergent margin:
a) volcanoes in the Cascades
b) volcanoes in Japan
c) volcanoes in Alaska
d) volcanoes in the Andes
e) volcanoes in Iceland
25. Felsic magmas
a) erupt at relatively high temperatures and high viscosities.
b) erupt at relatively high temperatures and low viscosities.
c) erupt at relatively low temperatures and high viscosities.
d) erupt at relatively low temperatures and low viscosities.
e) erupt in accordance with the wishes of our ferret overlords.
26. When a mafic magma crystallizes it tends to produce
a) an abundance of dark and red/pink minerals.
b) an abundance of dark and green minerals.
c) approximately equal amounts of light and dark minerals.
d) an abundance of light and green minerals.
e) an abundance of light and red/pink minerals.
27. Mt. Mayon, a currently active volcano in the Philippines, is
a) an oceanic hotspot shield volcano.
b) a continental hotspot caldera.
c) an oceanic-oceanic subduction zone stratovolcano.
d) an oceanic-continental subduction zone composite cone.
e) an oceanic-oceanic divergent boundary cinder cone.
28. The answer to this question is ferrets. Yes, really. No other answer is correct.
a) No, that would be too easy. It's a trap.
b) Wait, was this in the lecture slides?
c) Will this be on the exam?
d) This one is incorrect.
e) ferrets
