Quiz 4: Volcanism and Extrusive Rocks
Geology/Geography/Oceanography/Atmospheric Sciences
Q 1Q 1
Measurements indicate that the worldwide average temperature dropped about a half degree Celsius for a couple of years after the eruption of Mt. St. Helens.
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True False
False
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True False
True
Q 3Q 3
Major volcanic peaks of the Cascade Mountains, like Mt. Rainier, Mt. Shasta, Mt. Hood, and Mt. St. Helens, have been active volcanoes for 30 to 40 million years.
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True False
False
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True False
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True False
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True False
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True False
Q 8Q 8
Volcanic rocks, and the magma from which they formed, have a silica content that ranges from 45% to 75% by volume.
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True False
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True False
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True False
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True False
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True False
Q 13Q 13
Volcanic domes are steep-sided domes or spine-shaped masses of volcanic rock formed from viscous lava that solidifies in or immediately above a volcano's vent.
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True False
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True False
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True False
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True False
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True False
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True False
Q 19Q 19
The islands of Hawaii are essentially a series of shield volcanoes built upward from the ocean floor over millions of years.
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True False
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True False
Q 21Q 21
The last volcano to erupt in the continental 48 states was __.
A) Mount Garibaldi
B) Mount Rainer
C) Mount Mazama
D) Mount St. Helens
E) Mount Fuji
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Multiple Choice
Q 22Q 22
The term ___ is used for molten rock on the Earth's surface.
A) lava
B) tuff
C) magma
D) tephra
E) cinder
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Multiple Choice
Q 23Q 23
A(n) _______ is a mix of gas and dust emitted by a volcano that is so dense that it hugs the ground.
A) pyroclastic flow
B) pahoehoe flow
C) obsidian
D) lava flow
E) tuff flow
Free
Multiple Choice
Q 24Q 24
Condensation of the water vapor by degassing magma during the time following Earth's formation produced the ____.
A) atmosphere
B) geosphere
C) hydrosphere
D) magneosphere
E) biosphere
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Multiple Choice
Q 25Q 25
The islands of the Hawaiian chain are an excellent example of a series of __.
A) cinder cones
B) composite volcanoes
C) spatter cones
D) shield volcanoes
E) strata volcanoes
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Multiple Choice
Q 26Q 26
_____ are tunnel-like caves within a lava flow.
A) Pores
B) Vesicles
C) Lava tubes
D) Lava pipes
E) Calderas
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Multiple Choice
Q 27Q 27
Shield volcanoes have ___ bases and ___ inclined slopes.
A) broad; steeply
B) broad; gently
C) narrow; steeply
D) narrow; gently
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Multiple Choice
Q 28Q 28
Occasionally, a volcano will spew large amounts of fine volcanic dust into the high atmosphere. This dust can have the effect of __.
A) reducing the sunlight that reaches Earth's surface, suppressing photosynthetic processes
B) reducing Earth's surface temperature
C) damaging aircraft that fly through the dust
D) causing unusual weather
E) All of the answers are correct.
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Multiple Choice
Q 29Q 29
What are the three factors that influence viscosity of a lava?
A) depth of magma, temperature, ease of gas escaping to atmosphere
B) amount of gas, rhyolite, and vesicules in the magma
C) origin of the magma, plate tectonic setting, condensation
D) plate tectonic setting, thickness of the geosphere, amount of gas in the magma
E) silica content, temperature, dissolved gases
Free
Multiple Choice
Q 30Q 30
A _____ is a mixture of gas and pyroclastic debris that is so dense that it hugs the ground as it flows rapidly into low areas.
A) silica flow
B) lava flow
C) pyroclastic flow
D) change in viscosity
E) pahoehoe lava flow
Free
Multiple Choice
Q 31Q 31
The Roman city of _____ was destroyed by the eruption of Vesuvius in 79 AD.
A) Rome
B) Pompeii
C) St. Pierre
D) Naples
E) Florence
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Multiple Choice
Q 32Q 32
The more _____ the lava, and the greater the amount of gas trying to escape, the more violent the eruption.
A) viscous
B) fluid
C) hot
D) older
E) oxygenated
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Multiple Choice
Q 33Q 33
How do scientists indicate the power of a volcanic eruption?
A) Viscosity charts
B) Volcanic Explosivity Index
C) Hawaiian volcanic index
D) Dissolved gas charts
E) Volcanic Eruptive Indicator
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Multiple Choice
Q 34Q 34
Because _____ magmas are the most viscous they are associated with the most violent eruptions.
A) silica-rich
B) iron-rich
C) carbon dioxide-rich
D) water-rich
E) older
Free
Multiple Choice
Q 35Q 35
The most abundant silicic volcanic rock is __.
A) basalt
B) andesite
C) rhyolite
D) tuff
E) obsidian
Free
Multiple Choice
Q 36Q 36
The most common mafic volcanic rock is __.
A) basalt
B) andesite
C) rhyolite
D) tuff
E) obsidian
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Multiple Choice
Q 37Q 37
A _____ volcano is composed of alternating layers of pyroclastic fragments and solidified lava flows.
A) shield
B) composite
C) cinder cone
D) caldera
E) plateau
Free
Multiple Choice
Q 38Q 38
_________ crystallizes from an intermediate composition lava.
A) Andesite
B) Basalt
C) Gabbro
D) Composite
E) Rhyolite
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Multiple Choice
Q 39Q 39
Eruptions of shield volcanoes fed by mafic magma tend __.
A) to be violent and potentially dangerous events
B) to be explosive but short-lived
C) not to be explosive or particularly dangerous
D) to result in the expulsion of vast amounts of tephra
E) to cover the surrounding landscape in ash
Free
Multiple Choice
Q 40Q 40
Volcanic domes are steep-sided, spine-shaped masses of volcanic rock formed from _______ magma.
A) viscous
B) fluid
C) mafic
D) unusually hot
E) low-viscosity
Free
Multiple Choice
Q 41Q 41
_____ refers to a rock's appearance with respect to the size, shape, and arrangement of its grains or other constituents.
A) Crystallinity
B) Texture
C) Extrusiveness
D) Magma
E) Viscosity
Free
Multiple Choice
Q 42Q 42
_________ is a hill or mountain formed by the extrusion of lava or ejection of rock fragments from a vent.
A) Caldera
B) Flank eruption
C) Pillow lava
D) Volcano
E) Cinder cone
Free
Multiple Choice
Q 43Q 43
The eruption of ______ is related to the fact that the North American plate is overriding a portion of the Pacific Ocean floor.
A) Fuji
B) Tamboro
C) Mount St. Helens
D) Mount Pelee
E) Mauna Loa
Free
Multiple Choice
Q 44Q 44
In 1902 the port city of St. Pierre on the island of Martinique was destroyed by a ___.
A) tsunami
B) lava flow
C) mud flow
D) poison gas cloud
E) pyroclastic flow
Free
Multiple Choice
Q 45Q 45
Over 34,000 people died as a result of the ______ generated by the eruption of Krakatoa in 1883.
A) tidal wave
B) suzuki
C) roller
D) tsunami
E) whitecap
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Multiple Choice
Q 46Q 46
Crater Lake is a volcanic feature of _____.
A) the Cascade Mountains
B) Hawaii
C) the Aleutian Islands
D) the Ouachita Mountains
E) Baja California
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Multiple Choice
Q 47Q 47
A _________ is a volcanic depression much larger than the original crater, formed when the volcano collapses into a vacated magma chamber.
A) vent
B) caldera
C) basin
D) ring dike
E) crater
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Multiple Choice
Q 48Q 48
A ________ igneous rock is one in which larger crystals are enclosed in a groundmass of much finer-grained material.
A) aphanitic
B) phaneritic
C) polyphonic
D) porphyritic
E) mylonitic
Free
Multiple Choice
Q 49Q 49
________ is a frothy volcanic glass with so much void space that it can actually float.
A) Obsidian
B) Sponge rock
C) Pumice
D) Lava
E) A floater
Free
Multiple Choice
Q 50Q 50
The largest pyroclasts are __.
A) ash and dust
B) bombs/blocks
C) cinders
D) lapillis
E) sand
Free
Multiple Choice
Q 51Q 51
_____ describes the surface of a basalt flow with a smooth ropy surface.
A) Pahoehoe
B) Aa
C) Haleakela
D) Poy
E) Pele's hair
Free
Multiple Choice
Q 52Q 52
_____ describes the surface of a basalt flow with a jagged, rubble surface.
A) Pahoehoe
B) Aa
C) Haleakela
D) Poy
E) Pele's hair
Free
Multiple Choice
Q 53Q 53
Individual layers of basalt lava may be divided into vertical columns called ______.
A) pahoehoe
B) columnar basalt
C) pillow structure
D) collapse structure
E) tuff
Free
Multiple Choice
Q 54Q 54
A ______ is a volcano constructed of pyroclastic fragments ejected from a central vent.
A) shield volcano
B) caldera
C) stratovolcano
D) dome
E) cinder cone
Free
Multiple Choice
Q 55Q 55
________ is a rock composed of fine-grained pyroclastic particles.
A) Tuff
B) Pumice
C) Scoria
D) Rhyolite
E) Obsidian
Free
Multiple Choice
Q 56Q 56
________ are cavities in extrusive rocks resulting from gas bubbles in the lava.
A) Phenocrysts
B) Pleochroic
C) Vesicles
D) Vascular
E) Holy
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Multiple Choice
Q 57Q 57
Several times in Earth's history, outpourings of magma covered many thousands of square kilometers in multiple flows called __.
A) pillow basalts
B) plateau basalts
C) rift basalts
D) sheet basalts
E) regional basalts
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Multiple Choice
Q 58Q 58
A _________, a mixture of gas and volcanic debris, may blast out laterally under a viscous plug capping a volcano.
A) pyroclastic flow
B) mud flow
C) debris flow
D) lava flow
E) lahar
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Multiple Choice
Q 59Q 59
Radar images of which planet show a surface that is young and still volcanically active?
A) Mercury
B) Venus
C) Mars
D) Neptune
E) Saturn
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Multiple Choice
Q 60Q 60
Most of the better known composite volcanoes on Earth are __.
A) in the mid-ocean ridge system
B) in the circum-Pacific belt
C) in the Mediterranean belt
D) All of the choices are correct.
E) All of the choices are correct, except in the Mediterranean belt.
Free
Multiple Choice