Question 1

A ______ is a volcano constructed of pyroclastic fragments ejected from a central vent.

Accepted Answer

A) shield volcano 
B) caldera 
C) stratovolcano 
D) dome 
E) cinder cone 
A) shield volcano 
B) caldera 
C) stratovolcano 
D) dome 
E) cinder cone

Question 2

________ is a frothy volcanic glass with so much void space that it can actually float.

Accepted Answer

A) Obsidian 
B) Sponge rock 
C) Pumice 
D) Lava 
E) A floater 
A) Obsidian 
B) Sponge rock 
C) Pumice 
D) Lava 
E) A floater

Question 3

A _________ is a volcanic depression much larger than the original crater,formed when the volcano collapses into a vacated magma chamber.

Accepted Answer

A) vent 
B) caldera 
C) basin 
D) ring dike 
E) crater 
A) vent 
B) caldera 
C) basin 
D) ring dike 
E) crater

Question 4

Volcanic rocks,and the magma from which they formed,have a silica content that ranges from 45% to 75% by volume.

Accepted Answer

A) True 
 B)False

Question 5

Rhyolite is a fine-grained extrusive rock composed of feldspar with some quartz.

Accepted Answer

A) True 
 B)False

Question 6

The term ___ is used for molten rock on the Earth's surface.

Accepted Answer

A) lava 
B) tuff 
C) magma 
D) tephra 
E) cinder 
A) lava 
B) tuff 
C) magma 
D) tephra 
E) cinder

Question 7

_____ are tunnel-like caves within a lava flow.

Accepted Answer

A) Pores 
B) Vesicles 
C) Lava tubes 
D) Lava pipes 
E) Calderas 
A) Pores 
B) Vesicles 
C) Lava tubes 
D) Lava pipes 
E) Calderas

Question 8

The most common mafic volcanic rock is __.

Accepted Answer

A) basalt 
B) andesite 
C) rhyolite 
D) tuff 
E) obsidian 
A) basalt 
B) andesite 
C) rhyolite 
D) tuff 
E) obsidian

Question 9

Volcanic domes are steep-sided,spine-shaped masses of volcanic rock formed from _______ magma.

Accepted Answer

A) viscous 
B) fluid 
C) mafic 
D) unusually hot 
E) low-viscosity 
A) viscous 
B) fluid 
C) mafic 
D) unusually hot 
E) low-viscosity

Question 10

The last volcano to erupt in the continental 48 states was __.

Accepted Answer

A) Mount Garibaldi 
B) Mount Rainer 
C) Mount Mazama 
D) Mount St.Helens 
E) Mount Fuji 
A) Mount Garibaldi 
B) Mount Rainer 
C) Mount Mazama 
D) Mount St.Helens 
E) Mount Fuji

Question 11

The largest pyroclasts are __.

Accepted Answer

A) ash and dust 
B) bombs/blocks 
C) cinders 
D) lapillis 
E) sand 
A) ash and dust 
B) bombs/blocks 
C) cinders 
D) lapillis 
E) sand

Question 12

Most of the better known composite volcanoes on Earth are __.

Accepted Answer

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. 
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.

Question 13

Volcanic eruptions have no effect on climate.

Accepted Answer

A) True 
 B)False

Question 14

The islands of the Hawaiian chain are an excellent example of a series of __.

Accepted Answer

A) cinder cones 
B) composite volcanoes 
C) spatter cones 
D) shield volcanoes 
E) strata volcanoes 
A) cinder cones 
B) composite volcanoes 
C) spatter cones 
D) shield volcanoes 
E) strata volcanoes

Question 15

Occasionally,a volcano will spew large amounts of fine volcanic dust into the high atmosphere.This dust can have the effect of __.

Accepted Answer

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. 
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.

Question 16

Because _____ magmas are the most viscous they are associated with the most violent eruptions.

Accepted Answer

A) silica-rich 
B) iron-rich 
C) carbon dioxide-rich 
D) water-rich 
E) older 
A) silica-rich 
B) iron-rich 
C) carbon dioxide-rich 
D) water-rich 
E) older

Question 17

Pillow structures,pillow-shaped rounded masses,form where lava is extruded under water.

Accepted Answer

A) True 
 B)False

Question 18

Eruptions of shield volcanoes fed by mafic magma tend __.

Accepted Answer

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 
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

Question 19

How do scientists indicate the power of a volcanic eruption?

Accepted Answer

A) Viscosity charts 
B) Volcanic Explosivity Index 
C) Hawaiian volcanic index 
D) Dissolved gas charts 
E) Volcanic Eruptive Indicator 
A) Viscosity charts 
B) Volcanic Explosivity Index 
C) Hawaiian volcanic index 
D) Dissolved gas charts 
E) Volcanic Eruptive Indicator

Question 20

A _________,a mixture of gas and volcanic debris,may blast out laterally under a viscous plug capping a volcano.

Accepted Answer

A) pyroclastic flow 
B) mud flow 
C) debris flow 
D) lava flow 
E) lahar 
A) pyroclastic flow 
B) mud flow 
C) debris flow 
D) lava flow 
E) lahar

Exam 10: Volcanism and Extrusive Rocks

A ______ is a volcano constructed of pyroclastic fragments ejected from a central vent.

________ is a frothy volcanic glass with so much void space that it can actually float.

A _________ is a volcanic depression much larger than the original crater,formed when the volcano collapses into a vacated magma chamber.

Volcanic rocks,and the magma from which they formed,have a silica content that ranges from 45% to 75% by volume.

Rhyolite is a fine-grained extrusive rock composed of feldspar with some quartz.

The term ___ is used for molten rock on the Earth's surface.

_____ are tunnel-like caves within a lava flow.

The most common mafic volcanic rock is __.

Volcanic domes are steep-sided,spine-shaped masses of volcanic rock formed from _______ magma.

The last volcano to erupt in the continental 48 states was __.

The largest pyroclasts are __.

Most of the better known composite volcanoes on Earth are __.

Volcanic eruptions have no effect on climate.

The islands of the Hawaiian chain are an excellent example of a series of __.

Occasionally,a volcano will spew large amounts of fine volcanic dust into the high atmosphere.This dust can have the effect of __.

Because _____ magmas are the most viscous they are associated with the most violent eruptions.

Pillow structures,pillow-shaped rounded masses,form where lava is extruded under water.

Eruptions of shield volcanoes fed by mafic magma tend __.

How do scientists indicate the power of a volcanic eruption?

A _________,a mixture of gas and volcanic debris,may blast out laterally under a viscous plug capping a volcano.

Introducing Geology,the Essentials of Plate Tectonics,and Other Important Concepts

Earths Interior and Geophysical Properties

The Sea Floor

Plate Tectonics

Mountain Belts and the Continental Crust

Geologic Structures

Earthquakes

Time and Geology

Atoms,Elements and Minerals

Igneous Rocks, Intrusive Activity, and the Origin of Igneous Rocks

Weathering and Soil

Mass Wasting

Sediment and Sedimentary Rocks

Metamorphism, Metamorphic Rocks, and Hydrothermal Rocks

Streams and Floods

Ground Water

Deserts and Wind Action

Glaciers and Glaciation

Waves,Beaches and Coasts

Geologic Resources

The Earths Companions

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